(12) United States Patent (10) Patent No.: US 8,883,817 B2 Sadée Et Al

US008883817B2

(12) United States Patent (10) Patent No.: US 8,883,817 B2 Sadée et al. (45) Date of Patent: Nov. 11, 2014

(54) COMBINATION ANALGESIC EMPLOYING 5,972,954. A 10/1999 Foss et al...... 514,282 OPOD AND NEUTRAL ANTAGONST 6,004,970 A 12/1999 O'Malley etal 514,282 6,054,127 A 4/2000 Swain et al...... 424,194.1 w 6,110,503 A 8/2000 Rickey et al...... 424,501 (75) Inventors: Wolfgang Sadee, Upper Arlington, OH 6,136,817 A 10/2000 Schmidhammer ... 514,279 (US); Edward Bilsky, Biddeford, ME 6,194,006 B1 2/2001 Lyons et al...... 424/489 (US); Janet Yancey-Wrona, Freeport, 6,228,863 B1 5, 2001 Palermo et al. 514,282 ME (US) 6,271,240 B1 8/2001 Simon ...... 514,282 6,274,591 B1 8, 2001 Foss et al. .. 514,282 6,277.384 B1 8, 2001 Kaiko et al. (73) Assignee: AIKO Biotechnology, Portland, ME 6,306.425 B1 10/2001 Tice et al...... 424/400424/426 (US) 6,362,194 B1 3/2002 Crain et al. ... 514,285 6,375,957 B1 4/2002 Kaiko et al...... 424/400 (*) Notice: Subject to any disclaimer, the term of this 6,419,959 B1 7/2002 Walter et al...... 424/490 patent is extended or adjusted under 35 6,451,806 B2 9/2002 Farrar ...... 514,282 6,455,537 B1 9/2002 Cooper . 514,289 U.S.C. 154(b) by 943 days. 6,469,030 B2 10/2002 Farrar et al. 514,331 6,475,494 B2 11/2002 Kaiko et al. ... 424/400 (21) Appl. No.: 12/288,347 6,525,062 B2 2/2003 Levine ...... 514,282 6,528,271 B1 3/2003 Bohn et al. . 435/72 (22) Filed: Oct. 17, 2008 6,559,158 B1 5/2003 Foss et al. .. 514,282 6,559,159 B2 5/2003 Carroll et al. . 514,282 (65) Prior PublicationO O Data 6,569,8666.593,367 B2B1 7/20035/2003 SimonDewey et...... al. . 514,282514,561 US 2009/011 1844 A1 Apr. 30, 2009 6,608,075 B2 8, 2003 Foss et al...... 514,282 6,627,635 B2 9, 2003 Palermo et al. 514,282 O O 6,696,066 B2 2/2004 Kaiko et al...... 424/400 Related U.S. Application Data 6,713,488 B2 3/2004 Sadée et al. ... 514,282 (60) Provisional application No. 60/981,034, filed on Oct. 6,716,449 B2 4/2004 Oshlack et al. ... 424/449 6,734,188 B1 5, 2004 Rhodes et al. .... 514,282 18, 2007. 6,790,854 B2 9/2004 Tsushima et al...... 514,278 6,794,510 B2 9, 2004 Le Bourdonnec et al. ... 546,192 (51) Int. Cl. 6.825.205 B2 11/2004 Kyle ...... 514,282 A63/485 (2006.01) Continued A6 IK3I/37 (2006.01) (Continued) A6 IK 45/06 (2006.01) FOREIGN PATENT DOCUMENTS (52) U.S. Cl. CPC ...... A61K 45/06 (2013.01); A61 K3I/485 EP 1479 381 A1 11, 2004 (2013.01) EP 1263438 5, 2006 USPC ...... S14/282 (Continued) (58) Field of Classification Search USPC ...... 514/282 OTHER PUBLICATIONS See application file for complete search history. www.clinicaltrials.gov, APhase 2, Double-Blind, Multiple-Dose (56) References Cited Escalation Study to Evaluate NKTR-118 (Oral PEG-Naloxol) in Patients with Opioid-Induced Constipation (OIC), Sep. 27, 2009, 3 U.S. PATENT DOCUMENTS pageS. 3,523,906 A 8, 1970 Vrancken et al...... 252.316 (Continued) 3,691,090 A 9/1972 Kitajima et al...... 252/.316 3,737,337 A 6/1973 Schnoring et al...... 117,100 3,891,570 A 6, 1975 Fukushima et al. ... 252/.316 3,960,757 A 6, 1976 Morishita et al...... 252.316 Primary Examiner — Shirley V Gembeh 4,175,1194,176, 186 A 11,1 1/1979 1979 GoldbergPorter ...... et al. .4336 424,10 (74), Attorney, Agent, or Firm – Sunstein Kann Murphy & 4.389,330 A 6, 1983 Tice et al...... 427,213.36 Timbers LLP 4,457.933 A 7, 1984 Gordon et al. ... 424,260 4.459.278 A 7, 1984 Porter ...... 424,10 4,719,215 A 1/1988 Goldberg ...... 514,282 (57) ABSTRACT 4,760,069 A 7, 1988 RZeSZOtarski et ... 514,282 4,861,781 A 8/1989 Goldberg ...... 514,282 5.019.400 A 5, 1991 Gombotz et al. ... 424/497 A non-addictive analgesic co-formulation comprising an 5,472,943 A 12, 1995 Crain et al...... 514/12 opioid agonist in an amount Sufficient to confer analgesia in a 5,512.578 A 4, 1996 Crain et al...... 514,282 mammalian Subject and a neutral opioid antagonist in an 3. A 121: Real 35 amount sufficient to inhibit peripheral effects, and insufficient 5,656.297 A 8, 1997 Bernstein et al, r 424/484 to block substantial central effects, of the opioid agonist in the 5,767,125 A 6, 1998 Crain et al...... 514,282 Subject. Such formulations, and methods of using same, may 292 A S...... i. i 3. also deter diversion, inhibit peripheral effects, and reduce ckey et al. ... - - - - -

5,811,451 A 9, 1998 Minoia et al. E addiction liability. 5,852,032 A 12/1998 Mason ...... 514,282 5,916,598 A 6/1999 Rickey et al. 424,501 5,922,253 A 7, 1999 Herbert et al...... 264.5 28 Claims, 31 Drawing Sheets US 8,883,817 B2 Page 2

(56) References Cited European Patent Office, Jeans Arribrosch, Authorized Officer, Partial International Search Report dated Jun. 10, 2009; Application No. U.S. PATENT DOCUMENTS PCT/US2008/01 1915; 17 pages. Haider, Ursula, Authorized Officer, The International Search Report 6,919,350 B2 7/2005 Chang et al...... 514,282 and the Written Opinion of the International Searching Authority, 6,992,090 B2 1/2006 Le Bourdonnec et al. ... 514/317 International Application No. PCT/US2008/01 1915, International 7,008,939 B2 3/2006 Christoph ...... 514,212.01 Searching Authority, Sep. 30, 2009, 34 pages. 7,026,329 B2 4/2006 Crain et al...... 514,285 Marczak, et al., “N-Allyl-Dmtl-endomorphins are u-opioid recep 7,034,036 B2 4/2006 Schoenhard 514,282 7,041,320 B1 5/2006 Nuwayser ...... 424/497 tor antagonists lacking inverse agonist properties.” J. Pharmacol. 7,056,500 B2 6/2006 Bentley et al...... 424/78.18 Exp. Ther: Fast Forward (Jul 12, 2007). 7,091,354 B2 8, 2006 Le Bourdonnec et al. ... 546,236 Wang, et al., “Basal signaling activity of muopioid receptor in mouse 7,144,587 B2 12/2006 Oshlack et al...... 424/490 brain: role in narcotic dependence.” J Pharmacol Exp. Ther.; 7,172,767 B2 2/2007 Kaiko et al. ... 424/468 308(2): 512-20 (Feb. 2004 Epub Nov. 4, 2003). 7,196,100 B2 3/2007 Benesh et al. . 514,318 Raehal, et al., “In vivo characterization of 6B-naltrexol, an opioid 7,201.920 B2 4/2007 Kumar et al...... 424/454 ligand with less inverse agonist activity compared with naltrexone 2001.?004.9375 A1 12/2001 Sadée et al...... 514,282 and naloxone in opioid-dependent mice.” J Pharmacol Exp. Ther 2003. O18701.0 A1 10/2003 Foss et al. ... 514,282 313(3): 1150-62). (Jun. 2005; Epub Feb. 16, 2005). 2003,019 1147 A1 10/2003 Sherman et al. 514,282 Bilsky, et al., “Antinociceptive activity of beta-methyl-2',6'- 2003/0211157 A1 11/2003 Simon ...... 424/486 dimethyltyrosine(1)-substituted cyclic D-Pen(2), 2004.0024006 A1 2, 2004 Simon ...... 514,282 2004O162308 A1 8, 2004 Foss et al. 514,282 DPen(5) Enkephalin and D-Ala(2), Asp(4) Deltorphin analogs.” J 2004O167147 A1 8, 2004 Foss et al. ... 514,282 Pharmacol Exp Ther; 293(1): 151-8, 1999. 2004O167148 A1 8, 2004 Foss et al. 514,282 Cone, et al., “The Urinary Excretion Profile of Naltrexone and 2004/O18091.6 A1 9, 2004 Levine ..... 514,282 Metabolites in Man.” Drug Metab and Disp2(6): 506-512 (1974). 2004/0254208 A1 12/2004 Weber et al. 514,282 Wall, et al., “Metabolism and Disposition of Naltrexone in Man after 2005, OO38062 A1 2/2005 Burns et al. . 514,282 Oral and Intravenous Administration, Drug Metabolism and Dispo 2005. O165038 A1 7/2005 Gordon .... 514,282 sition' Drug Metabolism and Disposition, 9(4):369-375 (1981). 2006, OO69086 A1 3/2006 Michallow ...... 514, 220 Verebey K. “The Clinical Pharmacology of Naltrexone: Pharmacol 2006/011 1382 A1 5/2006 Shafer et al...... 514,282 ogy and Pharmacodynamics.” Naltrexone. NIDA Research Mono 2006/0235038 A1 10, 2006 Simon ...... 514,282 2007/00999.47 A1 5, 2007 Dean et al. .. 514,282 graph, 28, REWillette and G Barnett, eds. pp. 147-158 (1980). 2007/0105863 A1 5, 2007 Dolle et al. . 514,249 Wall, et al., “The Metabolism of Naltrexone in Man.” Naltrexone. 2007/O1975.73 A1 8/2007 Sadée et al. . 514,282 NIDA Research Monograph, 28, REWillette and G Barnett, eds. pp. 105-131 (1980). 2009/011 1844 A1 4/2009 Sadée et al...... 514,282 Perez-Reyes, et al., “A Comparative Study of the Oral, Intravenous, and Subcutaneous Administration f3 h-Naltrexone to normal male FOREIGN PATENT DOCUMENTS volunteers.” Naltrexone. NIDA Research Monograph 28, RE Wil WO WO 96/37775 11, 1996 lette and G Barnett, eds. pp. 93-101) (1980). WO WOO1? 6808O 9, 2001 Dunbar, et al., “Single- and Multiple-Dose Pharmacokinetics of WO WO 2004/05OO20 6, 2004 Long-acting Injectable Naltrexone.” Alcohol. Clin and Exper Res. WO WO 2007/O16108 2, 2007 30(3):48.0-490 (2006). Jayaram-Lindstrom, et al., “An open clinical trial of naltrexone for OTHER PUBLICATIONS amphetamine dependence: Compliance and tolerability.” Nord J Pschy. 59(3):167-171 (2005). M.C. Holden Ko, et al., Differential in Vivo Potencies of Naltrexone Brewer, et al., “Case Report. Naltrexone: report of lack of and 6B-Naltrexol in the Monkey, The Journal of Pharmacology and hepatotoxicity in acute viral hepatitis, with a review of the literature.” Experimental Therapeutics, vol. 316, No. 2, 2006, pp. 772-779. Addict Bio 9, 81-87) (2004). L. M. Sayre et al. (Abstract only), Importance of C-6 chirality in Chatterjie, et al., “Sterospecific synthesis of the 6B-Hydroxy Metabo conferring irreversible opioid antagonism to naltrexone-derived lites of Naltrexone and Naloxone.” J. Med. Chem., 18, pp. 490-492 afinity labels, NCBI, Sep. 26, 1983, 2 pages. (1975). Anna Ferari, et al. Serum time course of naltrexone and 6B-maltrexol Jiang, et al., J. Med. Chem. 20, pp. 1100-1102 (1977). levels during long term treatment in drug addicts, ScienceDirect, Plapp, B.V., “Control of Alcholo Metabolism.” pp. 311-322 Towards 1998, 2 pages. a Molecular Basis of Alcohol Use and Abuse, eds. Janssen et al., Sadée, et al., “Basal Opioid Receptor Activity, Neutral Antagonists, Birkhaeuser Verlag, 1994. and Therapeutic Opportunities.” Life Sciences, vol. 76, No. 13, Feb. Yancey-Wrona, et al., “6B-Naltrexol Prefrentially Antagonizes 11, 2005, pp. 1427-1437. Opioid Effects on Gastrointestinal Transit Compared to Antinociep Wang, et al., “Inverse Agonists and Neutral Antagonists at u Opioid tion in Mice' Life Sciences 85 (2009) 413-20. Receptor (MOR): Possible Role of Basal Receptor Signaling in Nar European Patent Office, Summons to Attend Oral Proceedings pur cotic Dependence.” Journal of Neurochemistry, vol. 77, No. 6, Jun. Suant to Rule 115(1) EPC International Application No. 08839342. 2001, pp. 1590-1600. 6—1216, dated Jan. 5, 2012 (16 pages). U.S. Patent Nov. 11, 2014 Sheet 1 of 31 US 8,883,817 B2

: 75 5 vo

HC 10 20 60 90 120 18O 6 hrs Control Time of Pre-treatment (min) (63-naltrexol 0.56 mg/kg, i.v.)

FIG 1A U.S. Patent Nov. 11, 2014 Sheet 2 of 31 US 8,883,817 B2

100

: 75 5 Yo

HC 15 30 60 90 120 180 6 hrs 12 hrs 24 hrs Control Time of Pre-treatment (min) (63-naltrexol 5.6 mg/kg, p.o.)

FIG 1B U.S. Patent Nov. 11, 2014 Sheet 3 of 31 US 8,883,817 B2

100 1N s CMJ 75 O w O g 50 O op w S < SNC 25

HC 0.10 0.18 0.32 0.56 Control Dose of 63-naltrexol (mg/kg, i.v.)

FIG 2A U.S. Patent Nov. 11, 2014 Sheet 4 of 31 US 8,883,817 B2

100

HC 1.0 1.8 3.2 5.6 Control -- Dose of 6f-naltrexol (mg/kg, p.o.)

FIG 2B U.S. Patent Nov. 11, 2014 Sheet 5 of 31 US 8,883,817 B2

100 Co-Administration (p.0.) 1. Y W -O-Hydrocodone Control > -9-6b-naltrexol (3.2 mg/kg) saO C W W -H-- 6b-naltrexol (32(10 mg/kg) w 80 N a-O-Saline Control JH N Y

.S. 60 O gld O A. op O QN O 40 a pu N)

C SS 20 S CS - M) N

O 30 60 90 120 150 180 Time (min) FIG 3 U.S. Patent Nov. 11, 2014 Sheet 6 of 31 US 8,883,817 B2

100

Saline HC 0.010 0.032 0.10 0.32 Control Control -- Dose of AIKO-150 (mg/kg, i.v.)

FIG 4A U.S. Patent Nov. 11, 2014 Sheet 7 of 31 US 8,883,817 B2

100

Saline HC 0.10 0.32 1.0 Control Control -- Dose of 6B-naltrexol (mg/kg, p.o.)

FIG 4B U.S. Patent Nov. 11, 2014 Sheet 8 of 31 US 8,883,817 B2

100

Saline HC 0.32 1.0 3.2 Control Control -- Dose of 63-naltrexol (mg/kg, p.o.)

FIG 5 U.S. Patent Nov. 11, 2014 Sheet 9 of 31 US 8,883,817 B2

O Hydrocodone (A90 i.v.) GI Transit -O-Hydrocodone (A90 i.v.) Antinociception 100

0.001 0.01 0.1 1 10 100 Dose of 63-maltrexol (mg/kg, i.v.) FIG 6A U.S. Patent Nov. 11, 2014 Sheet 10 of 31 US 8,883,817 B2

-O-Hydrocodone (A90 i.v.) GI Transit -O-Hydrocodone (A90 i.v.) Antinociception 100

0.001 0.01 0.1 l 10 100 Dose of 6B-naltrexol (mg/kg, p.o.) FIG 6B U.S. Patent Nov. 11, 2014 Sheet 11 of 31 US 8,883,817 B2

-O Hydrocodone (A90 p.o.) GI Transit 1. i-O- Hydrocodone (A90 p.o.) Antinociception > 100 s M SH 80 N

d 60 > s 40 O C O 2 20 PC

SNe O

0.001 0.01 0.1 1 10 100 Dose of 6B-naltrexol (mg/kg, p.o.) FIG 6C U.S. Patent Nov. 11, 2014 Sheet 12 of 31 US 8,883,817 B2

100 1. s CM)SH 75 O o w) O Od 50 O

op w

SNC 25 S. CN:

HC 20 60 90 120 180 Control - Time of Pre-treatment (min) (6 f-naltrexamide 10 mg/kg, i.v.)

FIG 7A U.S. Patent Nov. 11, 2014 Sheet 13 of 31 US 8,883,817 B2

100

75 5

50 ; 25 HC 30 60 120 18O 6 hrs. Control -- Time of Pre-treatment (min) (6 f3-maltrexamide 56 mg/kg, p.o.)

FIG 7B U.S. Patent Nov. 11, 2014 Sheet 14 of 31 US 8,883,817 B2

100

HC 1.0 3.2 10 Control -- Dose of 6B-naltrexamide (mg/kg, i.v.)

FIG 8A U.S. Patent Nov. 11, 2014 Sheet 15 of 31 US 8,883,817 B2

100

HC 10 18 32 56 Control t Dose of 63-naltrexamide (mg/kg, p.o.)

FIG 8B U.S. Patent Nov. 11, 2014 Sheet 16 of 31 US 8,883,817 B2

100 Co-Administration (p.o.) 1. -O-Hydrocodone Control > -G-6b-maltrexamide (100 mg/kg) -H 6b-naltrexamide (180 mg/kg) s Saline Control CMO 80 SH C O 60 O gld op9 9 O 40 o wo < e SN 20 N

O 30 60 90 120 150 180 Time (min) FG 9 U.S. Patent Nov. 11, 2014 Sheet 17 of 31 US 8,883,817 B2

100

Saline HC 0.032 0.10 0.32 Control Control -- Dose of 63-naltrexamide (mg/kg, i.v.)

FIG 10A U.S. Patent Nov. 11, 2014 Sheet 18 of 31 US 8,883,817 B2

100

Saline HC 1.0 1.8 3.2 Control Control -- Dose of 63-naltrexamide(mg/kg, p.o.)

FIG 10B U.S. Patent Nov. 11, 2014 Sheet 19 Of 31 US 8,883,817 B2

-O-Hydrocodone (A90 i.v.) GI Transit an O Hydrocodone (A90 i.v.) Antinociception > 100 s CM) 80

G9 60 > s 40 O C O 3 20 C

SSC O

0.001 0.01 0.1 1. 10 100 Dose of 63-naltrexamide (mg/kg, i.v.) FIG 11A U.S. Patent Nov. 11, 2014 Sheet 20 of 31 US 8,883,817 B2

-OHydrocodone (A90 i.v.) GI Transit -O-Hydrocodone (A90 i.v.) Antinociception 100

0.001 0.01 0.1 1 10 100 Dose of 63-maltrexamide (mg/kg, p.o.) FIG 11B U.S. Patent Nov. 11, 2014 Sheet 21 of 31 US 8,883,817 B2

100

HC 10 20 30 60 90 Control - Time of Pre-treatment (min) (Naltrexone 0.10 mg/kg, i.v.)

FG 12A U.S. Patent Nov. 11, 2014 Sheet 22 of 31 US 8,883,817 B2

100 1. s SHMD 75 O o wo O Gld 50 O op w < SNe 25 S. CS

HC 15 30 45 60 120 Control -- Time of Pre-treatment (min) (Naltrexone 0.56 mg/kg, p.o.)

FIG 12B U.S. Patent Nov. 11, 2014 Sheet 23 of 31 US 8,883,817 B2

100

HC 0.010 0.032 0.10 Control -- Dose of Naltrexone (mg/kg, i.v.)

FIG 13A U.S. Patent Nov. 11, 2014 Sheet 24 of 31 US 8,883,817 B2

100 1. ? CM) SH 75

O O d .2O 50 O

S. - SNC 25

HC 0.32 0.56 1.0 Control Dose of Naltrexone (mg/kg, p.o.)

FIG 13B U.S. Patent Nov. 11, 2014 Sheet 25 Of 31 US 8,883,817 B2

OO Co-Administration (p.o.) 1. -O-Hydrocodone Control > -e-Naltrexone (0.32 mg/kg) -H Naltrexone (1.0 mg/kg) ?a -- Naltrexone (3.2 mg/kg) w 80 arO- Saline Control SH

.S.ro 60

op9 9 e NM 40 w) MS

C SN 20 N

e s N

O 30 60 90 120 150 18O Time (min) FG 14 U.S. Patent Nov. 11, 2014 Sheet 26 of 31 US 8,883,817 B2

Saline HC 0.032 0.10 0.32 Control Control + Dose of Naltrexone (mg/kg, i.v.)

FG 15A U.S. Patent Nov. 11, 2014 Sheet 27 Of 31 US 8,883,817 B2

100

Saline HC 0.10 0.18 0.32 Control Control -- Dose of Naltrexone (mg/kg, p.o.)

FIG 15B U.S. Patent Nov. 11, 2014 Sheet 28 of 31 US 8,883,817 B2

100

Saline HC 0.32 1.0 3.2 Control Control -- Dose of Naltrexone (mg/kg, p.o.)

FIG 16 U.S. Patent Nov. 11, 2014 Sheet 29 Of 31 US 8,883,817 B2

On Hydrocodone (A90 i.v.) GI Transit iO Hydrocodone (A90 i.v.) Antinociception 100

0.001 0.01 0.1 l 10 100 Dose of Naltrexone (mg/kg, i.v.) FIG 17A U.S. Patent Nov. 11, 2014 Sheet 30 of 31 US 8,883,817 B2

-O-Hydrocodone (A90 i.v.) GI Transit 1. -O- Hydrocodone (A90 i.v.) Antinociception > 100 s CM) SH 80 CS gd 60 > s 40 O C O 2 20 C

SNC O

0.001 0.01 O.1 l 10 100 Dose of Naltrexone (mg/kg, p.o.) FIG 17B U.S. Patent Nov. 11, 2014 Sheet 31 of 31 US 8,883,817 B2

iO Hydrocodone (A90 p.o.) GI Transit 1. -O- Hydrocodone (A90 p.o.) Antinociception > 100 s M SH 80 p ex Y Gld 60 > s (9 40 O C O 2 20 C

SNC O

0.001 0.01 0.1 1 10 100 Dose of Naltrexone (mg/kg, p.o.) FIG 17C US 8,883,817 B2 1. 2 COMBINATION ANALGESCEMPLOYING ratio of naltrexol to opioid. Given the complete lack of Sup OPOD AND NEUTRAL ANTAGONST porting data, these Suggested dosages are uninformative and effectively meaningless, representing mere guesses. Further, CROSS REFERENCE TO RELATED Kaiko teaches the use of antagonists that have aversive effects APPLICATIONS in humans and precipitate severe withdrawal symptoms. Simon extrapolates to propose a dosage chart in paragraph This application claims priority from U.S. Provisional O156 for other kinds of opioid agonists. Application Ser. No. 60/981,034, filed in the United States Patent and Trademark Office on Oct. 18, 2007, which is hereby incorporated by reference herein. 10 SUMMARY OF THE INVENTION TECHNICAL FIELD The present invention teaches the use of an opioid/opioid antagonist co-formulation, co-administration of the agonist The present invention relates to co-formulations of opioid with the antagonist, or separate but overlapping administra agonists and opioid antagonists, and in particular to Such 15 tion of the agonist with the neutral antagonist, wherein Such co-formulations using neutral antagonists. co-formulation, co-administration or separate administration is uniquely designed to address both addiction liability of the BACKGROUND ART opioid and peripheral side effects, such as constipation. Opioid agonists, while creating analgesia in humans and In a first embodiment of the invention there is provided a other mammalian Subjects, typically are addictive and also unit dosage of an analgesic composition comprising an opioid typically have serious adverse side effects, including consti agonist in an amount Sufficient to confer analgesia in a mam pation and nausea. To address the addictive qualities of opioid malian Subject and a neutral opioid antagonist in an amount agonists, the prior art teaches the use of co-formulations that sufficient to inhibit peripheral effects, and insufficient to include both opioid agonists and opioid antagonists. Most 25 block substantial central effects, of the opioid agonist in the prior art co-formulations utilize opioid antagonists such as Subject. maltrexone or naloxone, which themselves have aversive effects in human and mammalian Subjects. In fact, these In a related embodiment of the invention the analgesic compounds can trigger severe, and sometimes life-threaten composition comprises an opioid agonist, which is selected ing, withdrawal symptoms. Such opioid antagonists are 30 from the group consisting of alfentanil, allylprodine, referred to in the present application as “aversive.” U.S. Pat. alphaprodine, anilleridine, benzylmorphine, bezitramide, No. 6,627,635 to Palermo et al. and U.S. Pat. Nos. 6,696,066, buprenorphine, butorphanol, clonitazene, codeine, desomor 6,475,494 and 6,375,957 to Kaiko et al. provide examples of phine, dextromoramide, dezocine, diampromide, diamor co-formulations that employ aversive opioid antagonists. phone, dihydrocodeine, dihydromorphine, dimenoxadol, Recent research by Marczak et al. emphasizes the aversive 35 dimepheptanol, dimethylthiambutene, dioxaphetylbutyrate, effects of both naltrexone and naloxone in opioid-dependent dipipanone, eptazocine, ethoheptazine, ethylmethylthiam subjects. Marczak E., Jinsmaa Y., Li T., Bryant S. D., Tsuda butene, ethylmorphine, etonitaZene, fentanyl, heroin, hydro Y., Okaday. Lazaraus L. H. (Jul 12, 2007)“N-Allyl-Dmt1 codone, hydromorphone, hydroxypethidine, isomethadone, endomorphins are u-opioid receptor antagonists lacking ketobemidone, levorphanol, levophenacylmorphan, lofenta inverse agonist properties. J. Pharmacol. Exp. Ther. Fast 40 nil, meperidine, meptazinol, metazocine, methadone, meto Forward. pon, morphine, myrophine, narceline, nicomorphine, nor U.S. Pat. No. 6,713,488 B2 to Wolfgang Sadée et al., which levorphanol, normethadone, noroxycodone, nalorphine, is hereby incorporated herein by reference and is hereinafter nalbuphene, normorphine, norpipanone, opium, oxycodone, referred to as “Sadée teaches the use of “neutral opioid oxymorphone, papaveretum, pentazocine, phenadoxone, antagonists, which do not have aversive effects, to treat opioid 45 phenomorphan, phenazocine, phenoperidine, piminodine, agonist addiction. Sadée identifies as neutral antagonists cer piritramide, propheptazine, promedol, properidine, pro tain naltrexone and naloxone analogs, including 6B-maltrexol and 6B-maltrexamide. Sadee also teaches that neutral antago poxyphene, Sufentanil, tilidine and tramadol, in an amount nists can be used to treat other side-effects of opioid agonists, Sufficient to confer analgesia in a mammalian Subject. In including constipation and respiratory depression. 50 addition, the neutral opioid antagonist may be a naloxone or Building on Sadee's research, United States Patent Appli maltrexone analog showing neutral nonaversive properties. cation 2004/0024006 A1 to David Lew Simon, hereinafter Naltrexone analogs may be represented by formula IC. or referred to as "Simon proposes non-addictive opioid ago IB, including pharmaceutically acceptable salts thereof: nist/antagonist co-formulations that include neutral opioid antagonists such as 6B-maltrexol. Simon's disclosure is pro 55 phetic in nature, however, and lacks Supporting, experimental (IC) data. For example, paragraphs 01 07 and 108 of Simon discuss a known effective dosage of morphine (0.15) mg/kg body weight) and then suggest a completely unknown and untested range of possible doses for 6.3-maltrexol from 60 0.00026-0.0015 mg/kg is body weight, providing no data for such a formulation ever being effective. Similarly, in para graph O155 of Simon's application, Simon uses data pro vided by Kaiko in the U.S. Pat. No. 6,475,494 to propose that 0.5 to 12 mg of 6f-naltrexol be administered per 15 mg 65 hydrocodone. These ratios of naltrexol to opioid range from 0.03:1 (i.e. 15.5-fold less naltrexol than opioid) to nearly a 1:1 US 8,883,817 B2 3 4 -continued -continued (IB) (IB) R12

N-R

wherein: wherein: R" is cycloalkyl(alkyl), for example, C-C, (cycloalkyl) 15 R" is alkenyl, for example C-C alkenyl, such as allyl, alkyl, for example, C-C (cycloalkyl)methyl such as (cyclo R’ is H, OH or esters thereof, such as —OAc(OC(alkyl)), propyl)methyl or Cs-C7 (cycloalkenyl)alkyl; for example O(C-C alkyl); R is H, OH or esters thereof, such as —OAc(OC(alkyl)), R is H, alkyl for example, C-C alkyl, or (alkyl)C=O for for example O(C-C alkyl); example, ((C-C)alkyl)-C=O; R is H. alkyl for example, C-C alkyl, or (alkyl)C=O for R" and Rare independently H, halogen (F, Cl, Br or I), example, ((C-C)alkyl)-C=O; alkyl, for example C-C alkyl, alkoxy, such as C-C alkoxy, R and Rare independently H, halogen (F, Cl, Br or I). nitro, amino, cyano, carboxyl or acyl which may be substi alkyl, for example C-C alkyl, alkoxy, such as C-C alkoxy, tuted for one or more hydrogens on the ring; nitro, amino, cyano, carboxyl or acyl which may be substi X' and X’ are the same or different, and may be H, alkyl, 25 OR, NR7RR, NCOR, NO, or SR'', tuted for one or more hydrogens on the ring; wherein, X' and X’ are the same or different, and may be H, C-C, RandR'' are independently H, alkyl, for example C-C, alkyl, OR, NRRR, NCOR', NO, or - SR'', alkyl, substituted alkyl, cycloalkyl, for example C-C, wherein, cycloalkyl, Substituted cycloalkyl, aryl, for example phenyl, RandR'' are independently H, alkyl, for example C-C, 30 naphthyl, imidazole, quinoline, isoquinoline, oxazole, ben alkyl, Substituted alkyl, cycloalkyl, for example C-C, ZOxazole, thiazole, pyrimidyl, pyrazolyl, indole, Substituted cycloalkyl, substituted cycloalkyl, aryl, for example phenyl, aryl, acyl, for example C-C, acyl such as —C(O)—C-C, naphthyl, imidazole, quinoline, isoquinoline, oxazole, ben alkyl wherein n is typically 6-10 but may be 10-20 or greater, ZOxazole, thiazole, pyrimidyl, pyrazolyl, indole, Substituted aroyl, for example benzoyl, naphthoyl, imidazoyl, quinoli aryl, acyl, for example C-C, acyl such as —C(O)C-C alkyl 35 noyl, isoquinolinoyl, oxazoyl, benzoxazoyl, thiazoyl, indoyl, whereinn is typically 6-10 but may be 10-20 or greater, aroyl, and pyrimidoyl, polyethyleneglycyl (PEGyl), or other similar for example benzoyl, naphthoyl, imidazoyl, quinolinoyl, iso Substitutions such as polyether groups; quinolinoyl, oxazoyl, benzoxazoyl, thiazoyl, indoyl, and R. R and R'' are independently hydrogen, alkyl, for pyrimidoyl, polyethyleneglycyl (PEGyl), or other similar example C-C alkyl Substituted alkyl, cycloalkyl for Substitutions such as polyether groups; 40 example C-C, cycloalkyl, Substituted cycloalkyl, aryl, Sub R. R. and R' are independently hydrogen, alkyl, for stituted aryl; example C-C alkyl, Substituted alkyl, cycloalkyl for R and R' can be present or absent and are independently example C-C cycloalkyl, Substituted cycloalkyl, aryl, Sub hydrogen, alkyl, for example C-C alkyl, Substituted alkyl, stituted aryl; cycloalkyl for example C-C cycloalkyl, Substituted 45 cycloalkyl, aryl, for example phenyl, naphthyl, imidazole, Rand R' can be present or absent and are independently quinoline, isoquinoline, oxazole, benzoxazole, thiazole, hydrogen, alkyl, for example C-C alkyl, substituted alkyl, pyrimidyl, pyrazolyl, indole, Substituted aryl; cycloalkyl for example C-C cycloalkyl, Substituted and pharmaceutically acceptable salts thereof. cycloalkyl, aryl, for example phenyl, naphthyl, imidazole, For generic formulae I C. and If, when X and X’ are the quinoline, isoquinoline, oxazole, benzoxazole, thiazole, 50 same, the stereocenter at this position, marked by an asterisk, pyrimidyl, pyrazolyl, indole, Substituted aryl; goes away. and pharmaceutically acceptable salts thereof. In related embodiments, the naloxone or naltrexone analog Naloxone analogs may be represented by formula ICl. or IB, may be, including 6B-maltrexol, 6B-maltrexamide, including pharmaceutically acceptable salts thereof: 6B-naloxol. 6C.-naltrexol. 6C.-naloxol. 6C.-naltrexamine, 55 6-deoxynaltrexone, 6B-maltrexamine, and 6C.-naltrexamide, pharmaceutically acceptable physical isomorphs thereof, and (IC) pharmaceutically acceptable salts thereof.

In a further related embodiment of the invention described above, the mammalian Subject is a human. 60 In another related embodiment of the invention described above, the analgesic composition is for oral or intravenous administration and the neutral opioid antagonist is 6B-maltr exol. Dosage ranges for the neutral antagonist relative to the analgesic, in separate formulations for co-administration, 65 may range from a dosage of approximately 0.0008-0.08 mg of 6f-naltrexol per kg of body weight of the subject for i.v. administration of both the antagonist and agonist, and from a US 8,883,817 B2 5 6 dosage range of approximately 0.008-0.24 mg 6 B-maltrexol amount of a unit dosage of a neutral opioid antagonist, the per kg of body weight for oral administration of both the effective amount sufficient to inhibit peripheral effects and antagonist and agonist, and from a dosage range of from insufficient to block substantial central effects in the subject. 0.008-0.08 mg of 6f-naltrexol per kg of body weight for oral A more particular embodiment provides a method of deter administration of the antagonistandi.V. administration of the ring addiction in a Subject being administered an opioid ago agonist. These dosage ranges were calculated as “human nist, the method comprising co-administering to the Subject equivalent dosages' from the effective dosages determined in the opioid agonist with an effective amount of a unit dosage of rodent models; it is anticipated that some dosage adjustment a neutral opioid antagonist, the effective amount Sufficient to be made for other species, and specifically humans. The dos reduce euphoria and reduce pain relief upon Successive age for the analgesic in separate formulations suitable for 10 administrations beyond therapeutically recommended limits, co-administration with the neutral antagonist, was an Ago thereby deterring addiction. dosage, which means it confers 90% analgesic activity. In related method embodiments, the unit dosage of the In another related embodiment of the invention described opioid antagonist is selected from the group consisting of above, the neutral opioid antagonist is 6B-maltrexol in a dos 6.3-maltrexol. 6(B-naltrexamide, 6 B-naloxol. 6C.-naltrexol, age of approximately 0.0008-0.24 mg per kg of body weight 15 6C.-naloxol. 6O-maltrexamine, 6B-maltrexamine, 6-deoxynal of the subject. trexone, and 6C.-naltrexamide, pharmaceutically acceptable In another related embodiment of the invention described physical isomorphs thereof, and pharmaceutically acceptable above, the neutral opioid antagonist is 6B-maltrexamide in a salts thereof. dosage of approximately 0.0024-0.8 mg per kg of body In other related method embodiments, the opioid agonist weight of the subject. and unit dosage may be administered in a manner selected In another related embodiment of the invention described from the group consisting of orally, perorally, intragastrically, above, the analgesic composition is co-administered orally Sublingually, by Suppository, intravenously and a combina with neutral opioidantagonist. In still further related embodi tion thereof, and wherein co-administration is overlapping ments, the neutral opioid antagonist is 6B-maltrexamide in an Such that administration may be of a single co-formulation oral administration with the agonist given by i.V., wherein the 25 comprising agonistandantagonist, or may be simultaneous or neutral antagonist dosage is approximately 0.024-0.8 mg per sequential administration of separate agonist and antagonist kg of body weight of the Subject. Again, the analgesic is given formulations. at an Ago dose. In various related embodiments of this invention, the Similar ranges are determined, as indicated, for other neu opioid agonist of the analgesic composition is hydrocodone. tral antagonists of the present invention. 30 In other particular embodiments, the unit dosage, pharmaceu Another embodiment comprises a method for inhibiting tical composition, and any or all of the methods may further peripheral effects of an opioid agonist while still permitting comprise a neutral opioid antagonist that is suitable for for Substantial central effects of the opioid agonist in a subject, mulation in a slow-release formulation, or is formulated in a the method comprising co-administering the opioid agonist slow-release formulation. with an effective amount of a unit dosage of a neutral opioid 35 In a further related embodiment of the invention described antagonist formulated as described to a subject in need above, the neutral opioid antagonist has a blood half-life thereof. substantially longer than the blood half-life of the opioid Still another embodiment provides a method of deterring agonist, so that repeated abusive administration of the dosage addiction in a subject being administered an opioid agonist, causes a greater increase in blood concentration of the the method comprising co-administering the opioid agonist 40 antagonist than of the agonist, so as to deter diversion, dis with an effective amount of a unit dosage of a neutral opioid courage abuse and/or reduce addiction liability to the agonist antagonist formulated according to as described to a subject resulting from Such administration. in need thereof. In a further related embodiment of the invention described In related embodiments, the opioid agonistand unit dosage above, the neutral antagonist has physicochemical properties are administered orally, perorally, intragastrically, Sublin 45 similar to that of the opioid agonist, so as to deter diversion of gually, by Suppository, or intravenously. the agonist by extraction or other means. Other embodiments provide a pharmaceutical formulation In various embodiments, whether the embodiments are that deters diversion of an opioid agonist, the formulation methods for inhibiting peripheral effects, deterring diversion comprising an amount of opioid agonist Sufficient to induce a or addiction, or reducing addiction liability, among other euphoric State or Sufficient to relieve pain upon ingestion or 50 methods, are whether the embodiments are for a unit dosage administration, the opioid agonist having a blood half-life, or a pharmaceutical composition, the neutral antagonist may and an effective amount of a neutral opioid antagonist with a be formulated alone or together with the opioid agonist in a ratio fixed relative to that of the opioid agonist, the neutral slow-release co-formulation. In Such co-formulations, the antagonist having a blood half-life Substantially longer than neutral antagonist may be provided with an opioid agonist the blood half-life of the opioid agonist, wherein upon suc 55 wherein only the neutral antagonist is provided in a slow cessive administration, the blood concentration ratio of neu release form. Other embodiments provide a neutral antago tral opioid antagonist to opioid agonist increases with each nist with an opioid agonist in a co-formulation, wherein only Successive administration, as measured in mg per kg of body the opioid agonist is provided in the co-formulation in a weight of the Subject, and Such that repeated administration of slow-release form. Still other embodiments provide a neutral the formulation in a dosage regimen exceeding therapeuti 60 antagonist with the opioid agonist in a co-formulation, cally recommended limits results in reduced euphoria and wherein both the neutral antagonist and the opioid agonist are reduced pain relief in the subject and so deters diversion. formulated as slow-release agents. Yet another embodiment provides a method for inhibiting To deter diversion the neutral antagonist of the present peripheral effects of an opioid agonist while still permitting invention is relatively lipophilic, similar to the agonists; Substantial central effects of the opioid agonist in a Subject in 65 moreover, greatest protection against diversion is achieved by need thereof, the method comprising co-administering to the making the two components in a co-formulation not easily subject in need thereof the opioid agonist with an effective separable. Further, the neutral antagonist is potent and is at US 8,883,817 B2 7 8 least partially excluded from the brain, not primarily by FIG. 7A is a graph that shows data reflecting the duration of means of high polarity, which also tends to reduce receptor the inhibitive effects of intravenously-administered 6,3-maltr potency (such as occurs with methylmaltrexone (MNTX)), examide on an antinociceptive, intravenous dose of hydroc but by other means, including but not limited to, the action of odone, and demonstrates the time of peak effect of antinoci an extrusion pump (e.g. —the multi-drug resistance pump 5 ception inhibition. MDR1, which also keeps loperamide (immodium) out of the FIG. 7B is a graph that shows data reflecting the duration of brain). The combination of these features makes the com the inhibitive effects of orally-administered 6,3-maltrexamide pounds of the invention unique. Lastly, Such potent and rela on an antinociceptive, intravenous dose of hydrocodone, and tively lipophilic antagonists have the tendency to show sig demonstrates the time of peak effect of antinociception inhi nificantly delayed central activity (for kinetic reasons) 10 bition. compared to peripheral effects. This is advantageous for short FIG. 8A is a dose response curve reflecting the potency of term use, and it facilitates dosage schedules that prevent the inhibitive effects of intravenously-administered 6,3-maltr inappropriate dosage escalation. examide on an antinociceptive, intravenous dose of hydroc 15 odone. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 8B is a dose response curve reflecting the potency of the inhibitive effects of orally-administered 6,3-maltrexamide The foregoing features of the invention will be more on an antinociceptive, intravenous dose of hydrocodone. readily understood by reference to the following detailed FIG. 9 is a graph that shows data reflecting the potency of description, taken with reference to the accompanying draw the inhibitive effects of various concentrations of orally-ad ings, in which: ministered 6B-maltrexamide on an orally-co-administered, FIG. 1A is a graph that shows data reflecting the duration of antinociceptive dose of hydrocodone. the inhibitory effects of intravenously-administered 6,3-nal FIG. 10A is a dose response curve reflecting the potency of trexol on an antinociceptive, intravenous dose of hydroc intravenously-administered 6 B-maltrexamide to reverse odone, and demonstrates the time of peak effect of antinoci 25 hydrocodone-induced GI transit slowing, where the two com ception inhibition. pounds are not co-administered. FIG.1B is a graph that shows data reflecting the duration of FIG. 10B is a dose response curve reflecting the potency of the inhibitive effects of orally-administered 6,3-maltrexol on orally-administered 6.3-maltrexamide to reverse hydroc an antinociceptive, intravenous dose of hydrocodone, and odone-induced GI transit slowing, where the two compounds demonstrates the time of peak effect of antinociception inhi 30 are not co-administered. bition. FIG. 11A shows the summarized potency data for inhibi FIG. 2A is a dose response curve reflecting the potency of tion of hydrocodone activity by 6B-maltrexamide in GI transit the inhibitive effects of intravenously-administered 6,3-maltr studies (peripheral effects) and antinociception studies (cen exol on an antinociceptive, intravenous dose of hydrocodone. tral effects), where both 6 B-maltrexamide and hydrocodone FIG. 2B is a dose response curve reflecting the potency of 35 were administered intravenously at different times. the inhibitive effects of orally-administered 6,3-maltrexol on FIG. 11B shows the summarized potency data for inhibi an antinociceptive, intravenous dose of hydrocodone. tion of hydrocodone activity by 6.f3-maltrexamide in the GI FIG. 3 is a graph that shows data reflecting the potency of transit studies (peripheral effects) and antinociception studies the inhibitive effects of various concentrations of orally-ad (central effects), where 6f-naltrexamide was administered ministered 6B-maltrexol on an orally-co-administered, anti 40 orally and hydrocodone was administered intravenously at nociceptive dose of hydrocodone. different times. FIG. 4A is a dose response curve reflecting the potency of FIG. 12A is a graph that shows data reflecting the duration intravenously-administered 6B-maltrexol to reverse hydroc of the inhibitive effects of intravenously-administered naltr odone-induced GI transit slowing, where the two compounds exone on an antinociceptive, intravenous dose of hydroc are not co-administered. 45 odone, and demonstrates the time of peak effect of antinoci FIG. 4B is a dose response curve reflecting the potency of ception inhibition. orally-administered 6f-naltrexol to reverse hydrocodone-in FIG.12B is a graph that shows data reflecting the duration duced GI transit slowing, where the two compounds are not of the inhibitive effects of orally-administered naltrexone on co-administered. an antinociceptive, intravenous dose of hydrocodone, and FIG. 5 is a dose response curve reflecting the potency of 50 demonstrates the time of peak effect of antinociception inhi 6.3-maltrexol to reverse hydrocodone-induced GI transit slow bition. ing when the two compounds are orally co-administered. FIG. 13A is a dose response curve reflecting the potency of FIG. 6A shows the summarized potency data for inhibition the inhibitive effects of intravenously-administered naltrex of hydrocodone activity by 6.3-maltrexol in GI transit studies one on an antinociceptive, intravenous dose of hydrocodone. (peripheral effects) and antinociception studies (central 55 FIG. 13B is a dose response curve reflecting the potency of effects), where both 6.3-maltrexol and hydrocodone were the inhibitive effects of orally-administered naltrexone on an administered intravenously. antinociceptive, intravenous dose of hydrocodone. FIG. 6B shows the summarized potency data for inhibition FIG. 14 is a graph that shows data reflecting the potency of of hydrocodone activity by 6.3-maltrexol in GI transit studies the antinociception-inhibitive effects of various concentra (peripheral effects) and antinociception studies (central 60 tions of orally-administered naltrexone on an orally-co-ad effects), where 6,3-maltrexol was administered orally and ministered, antinociceptive dose of hydrocodone. hydrocodone was administered intravenously. FIG. 15A is a dose response curve reflecting the potency of FIG. 6C shows the summarized potency data for inhibition intravenously-administered naltrexone to reverse hydroc of hydrocodone activity by 6.3-maltrexol in the GI transit odone-induced GI transit slowing. studies (peripheral effects) and antinociception studies (cen 65 FIG.15B is a dose response curve reflecting the potency of tral effects) where both 6f-naltrexol and hydrocodone were orally-administered naltrexone to reverse hydrocodone-in orally co-administered. duced GI transit slowing. US 8,883,817 B2 9 FIG. 16 is a dose response curve reflecting the potency of maltrexone to reverse hydrocodone-induced GI transit slow (IB) ing when the two compounds are orally co-administered.

FIG. 17A shows the summarized potency data for inhibi tion of the effects of intravenously-administered hydroc odone by intravenously-administered naltrexone in the GI transit studies (peripheral effects) and antinociception studies (central effects). FIG. 17B shows the summarized potency data for inhibi 10 tion of the effects of intravenously-administered hydroc OS '' odone by orally-administered naltrexone in the GI transit studies (peripheral effects) and antinociception studies (cen tral effects). The alpha isomers of 6-Naltrexoland 6-Naltrexamide may FIG. 17C shows the summarized potency data for inhibi 15 be represented by the generic formula IC.: tion of the effects of hydrocodone by naltrexone in the GI transit studies (peripheral effects) and antinociception studies (IC) (central effects) where both compounds are orally co-admin istered.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

25 Definitions. As used in this description and the accompa nying claims, the following terms shall have the meanings indicated, unless the context otherwise requires: 6B-maltrexol is a naltrexone analog with the following Structure: 30 For generic formulae I C. and If, when X and X’ are the same, the stereocenter at this position, marked by an asterisk, goes away. “IDso value” refers to a dose which inhibits activity by 50%. 35 A blood half-life substantially longer than the blood half life of the opioid agonist’ as used herein means a blood half-life that is in the order of 2-fold greater, or more, as measured at t=60 min than that for the opioid agonist. “A dose” refers to the dose, for example of an opioid 40 agonist, which produces 90% analgesic activity. Pharmaceutically acceptable salts of the naltrexone and naloxone analogs, which are neutral antagonists at the L 6B-Naltrexol opioid receptor, include salts derived from an appropriate 45 base. Such as an alkali metal (for example, sodium, potas 6B-maltrexamide is a naltrexone analog with the following sium), an alkaline earth metal (for example, calcium, magne Structure: sium), ammonium and NX. (wherein X is C-C alkyl). Pharmaceutically acceptable salts of an amino group include salts of organic carboxylic acids such as acetic, lactic, tar 50 taric, malic, lactobionic, fumaric, and Succinic acids; organic Sulfonic acids such as methanesulfonic, ethanesulfonic, isethionic, benzenesulfonic and p-toluenesulfonic acids; and inorganic acids Such as hydrochloric, hydrobromic, Sulfuric, phosphoric and Sulfamic acids. 55 In enantiomeric forms, compounds of the invention include individual enantiomers of the compounds in single species form Substantially free of the corresponding enanti omer, as well as in admixture (in mixtures of enantiomeric pairs and/or in mixtures of multiple enantiomer species). 60 Opiates are a class of centrally acting compounds and are HO NHCOCH frequently used agents for pain control. Opiates are narcotic 6B-Naltrexamide agonistic analgesics and are drugs derived from opium, Such as morphine, codeine, and many synthetic congeners of mor phine, with morphine being the most widely used derivative. Compounds 6,3-Naltrexol and 6(3-Naltrexamide may be 65 Opioids are natural and synthetic drugs with morphine-like represented by the generic formula If, where the stereocenter actions and include the opiates. Opioids are narcotic agonistic at position 6 is indicated by an asterisk. analgesics which produce drug dependence of the morphine US 8,883,817 B2 11 12 type and are Subject to control under federal narcotics law of the naltrexone or naloxone at the 6-keto position results in because of their addicting properties. an additional chiral carbon in the analog, the Borientation at The chemical classes of opioids with morphine-like activ the newly formed chiral carbon is preferred over the C. orien ity are the purified alkaloids of opium consisting of phenan tation, although the latter may be also appropriate in certain threnes and benzylisoquinolines, semi-synthetic derivatives applications. This preference is based upon the probably of morphine, phenylpiperidine derivatives, morphinan slower conversion of the B analogs back to naloxone or nal derivatives, benzomorphan derivatives, diphenyl-heptane trexone. Further, if desired, conversion of the naltrexone or derivatives, and propionanilide derivatives. The principal naloxone analog can be blocked by any suitable inhibitory phenanthrenes are morphine, codeine, and thebaine. The agent. For example, in the case of 6B or 6C.-naloxol or naltr principal benzoisoquinolines are papaverine, a Smooth 10 muscle relaxant, and noscapine. Semi-synthetic derivatives exol, conversion of the –OH at the 6 position back to the keto of morphine include diacetylmorphine (heroin), hydromor functionality of the naloxone or naltrexone can be inhibited phone, oxymorphone, hydrocodone, apomorphine, etorpine, with alcohol dehydrogenase inhibitors, such as 4-meth and oxycodone. Phenylpiperidine derivatives include meperi ylpyrazole (Plapp, B. V., “Control of Alcohol Metabolism.” dine and its congeners diphenoxylate and loperamide, 15 pp. 311-322 in Towards a Molecular Basis of Alcohol Use and alphaprodine, anilleridine hydrochloride or phosphate, and Abuse, eds. Janssenet al., Birkhaeuser Verlag, 1994). Further, piminodine esylate. Morphinan derivatives include levorpha the replacement of the 6-keto functionality with, for example, nol. The diphenyl-heptane derivatives include methadone and an amine or amide resulting in 6C.- and 6B-maltrexamine and its congeners, and propoxyphene. Propionanilide derivatives maltrexamide is likely to undergo much slower, if any, con include fentanyl citrate and its congeners Sufentanil citrate version to naltrexone. and alfenatil hydrochloride. Other examples of potential neutral antagonists include the As used herein, a “therapeutically effective amount” refers C-6-H reduced analogue of naltrexol (access to the CNS++). to the amount of the naltrexone or naloxone analog or Sus whose molecular formula is CHNO, and whose IUPAC tained release composition having the naltrexone or naloxone name is 17-(cyclopropylmethyl)4.5-epoxy-3, 14-dihydroxy analog incorporated therein, needed to elicit the desired bio 25 morphinan but for the purposes of this application is referred logical response following administration. The desired bio to as 6-deoxynaltrexone. Still other possibilities for neutral logical response herein can be sufficient blockade of the L antagonists, based on the naloxone or naltrexone core formu opioid receptor resulting in reducing adverse effects associ las, can be envisioned, or may be identified, and are consid ated with current pain management Such as diarrhea and ered to fall within the scope of the invention and encompassed constipation and without significantly inhibiting the central 30 by the claims. For example, the C-6 position could be modi effects such as pain relief. fied in other ways, whether by replacement of the keto group The neutral antagonist compositions of this invention can with halogens, alkyl- and alkoxyl groups, alkylamine groups, be administered in vivo, for example, a human, or an animal. vinyl groups, secondary and tertiary amine groups, among Alternatively, a neutral antagonist can also be administered others, or by modification at other sites, or in other ways, that orally, transdermally, or parenterally such as by injection, 35 retain the neutral antagonist activity at the L receptor. implantation (e.g., Subcutaneously, intramuscularly, intrap This definition of neutral antagonist also encompasses eritoneally, intracranially, and intradermally), administration compounds that are not based on the naltrexone or naloxone to mucosal membranes (e.g., intranasally, intravaginally, core formulas, but may represent a new type of compound intrapulmonary, buccally or by means of a Suppository), or in that still possesses the properties associated with a neutral situ delivery (e.g., by enema or aerosol spray) to provide the 40 antagonist of the LL receptor. desired dosage of naltrexone or naloxone analog to modulate Thus, while the concept of neutral antagonist has been undesirable effects of narcotic analgesic (such constipation, particularly shown and described with references to preferred nausea, vomiting) in the treatment of pain oranesthesia, in an embodiments thereof, it will be understood by those skilled in individual in need thereof. the art that various changes in form and details to the neutral “Neutral antagonists’ as that term is used herein, refers to 45 antagonist core formulas, or to the development of com agents that block the effects of an agonist at the target recep pletely unrelated core formulas for neutral antagonists, may tor, but do not significantly affect the level of spontaneous be made therein without departing from the scope of the activity present at the target receptor. “Neutral antagonist at invention encompassed by the appended claims. the Lopioid receptor as that term is used herein refers to an The term “sustained release composition' as defined agent which can bind selectively to the resting, drug-sensitive 50 herein, can comprise a biocompatible polymer having incor L opioid receptor state, to the constitutively active L opioid porated therein at least one naloxone or naltrexone analog receptor State, or to both, blocking the effects of an agonist at which is a neutral antagonist at the Lopioid receptor. Suitable the receptor, but not significantly effecting the level of spon biocompatible polymers, can be either biodegradable or non taneous activity present at the receptor. biodegradable polymers or blends or copolymers thereof, as The naloxone and naltrexone analogs represented by the 55 described herein. structures presented hereincan be synthesized using standard The Sustained release compositions of the present inven synthetic procedures such as those described in March J., tions may comprise a neutral antagonist formulated alone or Advanced Organic Chemistry, 3rd Ed. (1985), employing, for together with an opioid agonist in a slow-release co-formu example, naltrexone or naloxone as the starting material. lation. In Such co-formulations, the neutral antagonist may be Many of the analogs of naltrexone and naloxone which 60 provided with an opioid agonist wherein only the neutral possess neutral antagonist activity at the Lopioid receptor, for antagonist is provided in a slow-release form. In other co example, the analogs wherein the 6-keto functionality has formulations with a neutral antagonist and an opioid agonist, been reduced to an —OH functionality, are known com only the opioid agonist is provided in the co-formulation in a pounds, and their syntheses have been described, for slow-release form. And in still other co-formulations with a example, by Chatterjie et al., J. Med. Chem., 18, pp. 490-492 65 neutral antagonist and an opioid agonist, both the neutral (1975) and Jiang et al., J. Med. Chem. 20, pp. 1100-1102 antagonist and the opioid agonist are formulated as slow (1977), incorporated by reference herein. When modification release agents. US 8,883,817 B2 13 14 The Sustained release compositions of this invention can be Acceptable molecular weights for polymers used in this formed into many shapes such as a film, a pellet, a rod, a invention can be determined by a person of ordinary skill in filament, a cylinder, a disc, a wafer or a microparticle. A the art taking into consideration factors such as the desired microparticle is preferred. A “microparticle' as defined polymer degradation rate, physical properties such as herein, comprises a polymer component having a diameter of 5 mechanical strength, and rate of dissolution of polymer in less than about one millimeter and having a naltrexone or Solvent. Typically, an acceptable range of molecular weight is naloxone analog which is a neutral antagonist at the L opioid of about 2,000 Daltons to about 2,000,000 Daltons. receptor dispersed therein. A microparticle can have a spheri In a particular embodiment, the polymer is biodegradable cal, non-spherical or irregular shape. Typically, the micropar polymer or copolymer. In a more preferred embodiment, the ticle will be of a size suitable for injection. A preferred size 10 polymer is a poly(lactide-co-glycolide) (hereinafter “PLG'). range for microparticles is from about one to about 180 The PLG can have a lactide:glycolide ratio, for example, of microns in diameter. about 10:90, 25:75, 50:50, 75:25 or 90:10 and a molecular As defined herein, a Sustained release of a naltrexone or weight of about 5,000 Daltons to about 70,000 Daltons. naloxone analog of the present invention is a release of the It is understood that when the naltrexone or naloxone ana agent from a Sustained release composition. As explained 15 log, which is a neutral antagonist at the L opioid receptor, or above, a Sustained release of a neutral antagonist with an when the opioid agonist, separately or in a co-formulation opioid agonist may be release of the antagonist, or release of with a neutral antagonist, is incorporated into a biocompatible the agonist, or release of both the neutral antagonist and the polymer for Sustained release of the analog and/oragonist, the opioid agonist from a Sustained release composition. The Sustained release composition can include additional compo release occurs over a period which is longer than that period nents which can stabilize the analog and/or modify the release during which a therapeutically significant amount of the profile of the naltrexone or naloxone analog from the Sus naloxone or naltrexone analog, or the opioid agonist, would tained release composition. That is, the naltrexone or nalox be available following direct administration of a solution of one analog, or opioid agonist, of the Sustained release com the analog. The period of Sustained release can be, for position can be stabilized against loss of potency and/or loss example, about one day, about two days, about seven days, 25 of activity, all of which can occur during formation of the about ten days to one month, or more, as needed to attain the Sustained release composition having the naltrexone or desired results. A Sustained release of a naltrexone or nalox naloxone analog and/or opioid agonist dispersed therein, and/ one analog of the invention from a Sustained release compo or prior to and during in vivo release of the analog and/or sition, or of an opioid agonist in a co-formulation with a agonist. In addition, the period of release of the naltrexone or neutral antagonist from a Sustained release composition, may 30 naloxone analog, and/or the opioid agonist, can be prolonged. be a continuous or a discontinuous release, with relatively A Suitable excipient or a specific combination of excipients constant or varying rates of release. The continuity of release can be employed in the sustained release composition. and level of release can be affected by the type of polymer “Excipient’, as that term is used herein, is any agent which composition used (e.g., monomer ratios, molecular weight, binds or interacts in a covalent or non-covalent manner or is and varying combinations of polymers), agent loading, and/ 35 included with the naloxone or naltrexone analog in the Sus or selection of excipients to produce the desired effect. tained release composition. The polymers of the Sustained release compositions Suitable excipients include, for example, carbohydrates, described herein are biocompatible. Suitable biocompatible amino acids, fatty acids, Surfactants, and bulking agents, and polymers, can be either biodegradable or non-biodegradable are known to those skilled in the art. An acidic or a basic polymers or blends or copolymers thereof, as described 40 excipient is also Suitable. The amount of excipient used is herein. based on ratio to the naltrexone or naloxone analog, on a Suitable biocompatible polymers, can be either biodegrad weight basis. Foramino acids, fatty acids and carbohydrates, able or non-biodegradable polymers or blends or copolymers Such as Sucrose, trehalose, lactose, mannitol, dextran and thereof, as described herein. A polymer is biocompatible if heparin, the ratio of carbohydrate to analog, is typically the polymer and any degradation products of the polymer are 45 between about 1:10 and about 20:1. For surfactants the ratio non-toxic to the recipient and also possess no significant of surfactant to analog is typically between about 1:1000 and deleterious or untoward effects on the recipient’s body, such about 2:1. Bulking agents typically comprise inert materials. as an immunological reaction at the injection site. Suitable bulking agents are known to those skilled in the art. “Biodegradable', as defined herein, means the composi The excipient can also be a metal cation component which tion will degrade or erode in vivo to form smaller chemical 50 acts to modulate the release of the naltrexone or naloxone species. Degradation can result, for example, by enzymatic, analog. A metal cation component used in modulating release chemical and physical processes. Suitable biocompatible, typically comprises at least one type of multivalent metal biodegradable polymers include, for example, poly(lactides), cation. Examples of metal cation components Suitable to poly(glycolides), poly(lactide-co-glycolides), poly(lactic modulate release include or contain, for example, Mg(OH), acid)S, poly(glycolic acid)S. polycarbonates, polyesteram 55 MgCO (such as 4MgCO.Mg(OH).5H2O), MgSO, ides, polyanhydrides, poly(amino acids), polyorthoesters, Zn(OAc), Mg(OAc), ZnCO (such as 3Zn(OH)2ZnCO), poly(dioxanone)S. poly(alkylene alkylate)S. copolymers or ZnSO, ZnCl2, MgCl, CaCO, Zn(CHO) and Mgs polyethylene glycol and polyorthoester, biodegradable poly (CHO). A suitable ratio of metal cation component to urethane, blends thereof, and copolymers thereof. polymer is between about 1:99 to about 1:2 by weight. The Suitable biocompatible, non-biodegradable polymers 60 optimum ratio depends upon the polymerand the metal cation include non-biodegradable polymers selected from the group component utilized. A polymer matrix containing a dispersed consisting of polyacrylates, polymers of ethylene-vinyl metal cation component to modulate the release of a an agent acetates and other acyl Substituted cellulose acetates, non from the polymer matrix is further described in U.S. Pat. No. degradable polyurethanes, polystyrenes, polyvinylchloride, 5,656.297 to Bernstein et al. the teachings of which are incor polyvinyl fluoride, poly(vinyl imidazole), chlorosulphonate 65 porated herein by reference in their entirety. polyolefin, polyethylene oxide, blends thereof, and copoly A number of methods are known by which sustained mers thereof. release compositions (polymer/active agent matrices) can be US 8,883,817 B2 15 16 formed. In many of these processes, the material to be encap emulsified in a solution of a polymeric material in a solvent Sulated is dispersed in a solvent containing a wall forming that is immiscible in water and then the emulsion is emulsified material. At a single stage of the process, Solvent is removed in an aqueous solution containing a hydrophilic colloid. Sol from the microparticles and thereafter the microparticle prod vent removal from the microparticles is then accomplished by uct is obtained. 5 evaporation and the product is obtained. Methods for forming a composition for the sustained release of biologically active agent are described in U.S. Pat. In still another process as shown in U.S. Pat. No. 3,691, No. 5,019,400, issued to Gombotzet al., and issued U.S. Pat. 090, incorporated herein by reference in its entirety, organic No. 5,922.253 issued to Herbert et al. the teachings of which Solventis evaporated from a dispersion of microparticles in an are incorporated herein by reference in their entirety. 10 aqueous medium, preferably under reduced pressure. In this method, a mixture comprising a biologically active Similarly, the disclosure of U.S. Pat. No. 3,891,570, incor agent, a biocompatible polymer and a polymer Solvent is porated herein by reference in its entirety, shows a method in processed to create droplets, wherein at least a significant which solvent from a dispersion of microparticles in a poly portion of the droplets contains polymer, polymer Solvent and hydric alcohol medium is evaporated from the microparticles the active. These droplets are then frozen by a suitable means. 15 by the application of heat or by Subjecting the microparticles Examples of means for processing the mixture to form drop to reduced pressure. lets include directing the dispersion through an ultrasonic noZZle, pressure nozzle, Rayleigh jet, or by other known Another example of a solvent removal process is shown in means for creating droplets from a solution. U.S. Pat. No. 3,960,757, incorporated herein by reference in Means suitable for freezing droplets include directing the its entirety. droplets into or near a liquified gas, such as liquid argon or Tice et al., in U.S. Pat. No. 4.389.330, describe the prepa liquid nitrogen to form frozen microdroplets which are then ration of microparticles containing an active agent by a separated from the liquid gas. The frozen microdroplets are method comprising: (a) dissolving or dispersing an active then exposed to a liquid or Solid non-solvent, such as ethanol, agent in a solvent and dissolving a wall forming material in hexane, ethanol mixed with hexane, heptane, ethanol mixed 25 that solvent; (b) dispersing the solvent containing the active with heptane, pentane or oil. agent and wall forming material in a continuous-phase pro The solvent in the frozen microdroplets is extracted as a cessing medium; (c) evaporatingaportion of the solvent from Solid and/or liquid into the non-solvent to form a polymer/ the dispersion of step (b), thereby forming microparticles active agent matrix comprising a biocompatible polymer and containing the active agent in the Suspension; and (d) extract a biologically active agent. Mixing ethanol with other non 30 Solvents, such as hexane, heptane or pentane, can increase the ing the remainder of the solvent from the microparticles. rate of solvent extraction, above that achieved by ethanol Further suitable methods of preparation are described in alone, from certain polymers, such as poly(lactide-co-gly U.S. Pat. No. 6,194,006 to Lyons et al., U.S. Pat. Nos. 6,110, collide) polymers. 503, 5,916,598 and 5,792.477 to Rickey et al. and U.S. Pat. A wide range of sizes of Sustained release compositions 35 No. 5,650,173 to Ramstack et al. the entire content of all of can be made by varying the droplet size, for example, by which is hereby incorporated by reference. changing the ultrasonic nozzle diameter. If the Sustained release composition is in the form of microparticles, and very While this invention has been particularly shown and large microparticles are desired, the microparticles can be described with references to preferred embodiments thereof, extruded, for example, through a syringe directly into the cold 40 it will be understood by those skilled in the art that various liquid. Increasing the Viscosity of the polymer Solution can changes in form and details may be made therein without also increase microparticle size. The size of the micropar departing from the scope of the invention encompassed by the ticles which can be produced by this process ranges, for appended claims. example, from greater than about 1000 to about 1 microme Effect of 6f-Naltrexol on Hydrocodone-Induced Antinocice ters in diameter. 45 ption Yet another method of forming a Sustained release compo sition, from a Suspension comprising a biocompatible poly Previous work confirms that 6f-naltrexol antagonizes the mer and a biologically active agent, includes film casting, central effects of opioids. For example, research by Wang D. Such as in a mold, to form a film or a shape. For instance, after Raehal K M, Bilsky E. J. Sadee W. (2001 June) “Inverse putting the Suspension into a mold, the polymer Solvent is 50 agonists and neutral antagonists at mu opioid receptor then removed by means known in the art, or the temperature (MOR): possible role of basal receptor signaling in narcotic of the polymer Suspension is reduced, until a film or shape, dependence. J Neurochem., 77(6):1590-600 showed that with a consistent dry weight, is obtained. 6B-maltrexol reverses morphine-induced antinociception A further example of a conventional microencapsulation when administered intraperitoneally. Other experiments have process and microparticles produced thereby is disclosed in 55 further shown that 6f-naltrexol prevents the stereotypic cir U.S. Pat. No. 3,737,337, incorporated by reference herein in cling induced by morphine in non-dependent and chronically its entirety, wherein a solution of a wall or shell forming dependent mice (Wang D. Raehal K. M., Lin E.T., Lowery J. polymeric material in a solvent is prepared. The solvent is J., Kieffer B. L., Bilsky E.J., Sadee W. (2004 February Epub only partially miscible in water. A solid or core material is 2003 Nov. 4) “Basal signaling activity of mu opioid receptor dissolved or dispersed in the polymer-containing mixture 60 in mouse brain: role in narcotic dependence. J Pharmacol and, thereafter, the core material-containing mixture is dis Exp Ther; 308(2): 512-20; Raehal K. M., Lowery J. J., Bha persed in an aqueous liquid that is immiscible in the organic midipati C.M., Paolino R. M., Blair J. R. Wang D. Sadee W. solvent in order to remove solvent from the microparticles. Bilsky E.J. (2005 June: Epub 2005 Feb. 16) “In vivo charac Another example of a process in which solvent is removed terization of 6B-maltrexol, an opioid ligand with less inverse from microparticles containing a Substance is disclosed in 65 agonist activity compared with naltrexone and naloxone in U.S. Pat. No. 3,523,906, incorporated herein by reference in opioid-dependent mice. J Pharmacol Exp. Ther its entirety. In this process a material to be encapsulated is 313(3):1150-62). US 8,883,817 B2 17 18 Experimental Data Demonstrates that 6f-Naltrexol Reverses sal of the hydrocodone-induced antinociception was calcu Hydrocodone-Induced Antinociception. lated as (test-hydrocodone control)/(saline control-hydroc odone control)*100. From this data an IDs value (and 95% Example 1 confidence interval) was calculated for each route using linear regression (FlashCalc software; Dr. Michael Ossipov, Uni Tail-Flick Assay versity of Arizona, Tucson, Ariz.). IDso values for 6B-maltr exol inhibition of hydrocodone-induced antinociception were Antinociception was assessed using a 55° C. warm-water determined to be 0.222 mg/kg (95% CI=0.194-0.253) for i.v. tail-flick assay (Bilsky E. J., Qian X. Hruby V. J., Porreca F. administration, and 2.35 mg/kg (95% CI-2.11-2.63) for oral (2000 April) “Antinociceptive activity of beta-methyl-2',6'- 10 administration, consistent with this compounds 14% bio dimethyltyrosine(1)-substituted cyclic D-Pen(2), D-Pen availability in the rodent (previously determined data not (5) Enkephalin and D-Ala(2), Asp(4) Deltorphin analogs.J. shown). Pharmacol Exp Ther; 293(1): 151-8; Raehal K. M., Lowery J. Antinociception Studies for Oral Co-Administration. J., Bhamidipati C. M., Paolino R. M., Blair J. R. Wang D., The tail-flick assay was used to construct full dose- and Sadee W., Bilsky E. J. (2005 June: Epub 2005 Feb. 16) “In 15 time-response Summaries for 63-maltrexol in combination Vivo characterization of 6beta-naltrexol, an opioid ligand with hydrocodone. Vehicle or various doses of 6f-naltrexol with less inverse agonist activity compared with naltrexone were orally co-administered with an Ago dose of hydrocodone and naloxone in opioid-dependent mice. J Pharmacol Exp (32 mg/kg, p.o.) determined previously (data not shown) at Ther 313(3): 1150-62). Male ICR mice (UNE) or CD-1 mice t=0 min. Tail-flick latencies were determined at t=10, 20, 30, (Charles River) 25-40 grams were used in all procedures. 45, 60.90, 120 and 180 minutes post injection (or until 20% Mice were weighed and the tails marked with indelible ink, MPE was reached) and % antinociception was calculated for with an in size of 8-10 mice/group. The latency to the first sign each mouse (FIG. 3). of a rapid tail-flick was used as the behavioral endpoint (Jan The antinociception experiments shown in FIG.3 yield an insen et al., 1963). Briefly, each mouse was tested for baseline IDso value of 12.3 mg/kg (95% CI=10.4-14.7) for 6 B-maltr latency by immersing the distal third of its tail into the water 25 exol co-administered with hydrocodone. bath and recording the time until a vigorous tail-flick The experiments shown in FIGS. 1-3 demonstrate that response to the noxious stimulus. Latencies typically aver 6B-maltrexol blocks hydrocodone-induced antinociception aged between 1.5 and 2.5 S in drug naive subjects with any regardless of the route of administration. mice having a baseline latency greater than 5 S eliminated Effect of 6f-Naltrexol on Hydrocodone-Induced Gas from further testing. Upon completion of baseline testing 30 trointestinal Tract Slowing mice were injected and retested for tail-flick latencies at vari ous times after injection (typically 10, 20, 30, 45, 60,90, 120 Example 2 and 180 minutes or until the test latency approaches the baseline latency, e.g., less than 20% MPE for the group.). A GI Transit Assay maximal score was assigned to mice not responding within 10 35 S to avoid tissue damage. The percentage of antinociception Opioid-induced GI inhibition was measured using a stan was calculated as (test latency-baseline latency)/(10-base dard protocol (Current Protocols in Pharmacology, number line latency)*100. 5.3). Male CD-1 mice (Charles River) 25-40 grams are used Antinociception Studies for Determining Time of Peak in all procedures. Mice are weighed and the tails marked with Effect of 6f-naltrexol. 40 indelible ink, with an in size of 8-10 mice/group. Mice were The duration of 6f-naltrexol effects was measured by pre deprived of food for approximately 18 hr prior to the start of treating mice with 63-maltrexol at various times prior to an the experiment. 6B-maltrexol or saline was injected at 1 injection of an antinociceptive Ago dose of hydrocodone (3.2 ml/100g bodyweight (route and pretreatment time vary) prior mg/kg, i.V., dose determined previously; data not shown). to an oral delivery of a charcoal suspension (constant Volume Mice were tested 10 min later at the time of peak effect for 45 of 250 LL). At t=0 minutes, the oral charcoal is delivered hydrocodone in the tail-flickassay. 6(3-maltrexol doses of 0.56 using an 18 gauge curved gavage needle (Popper & Sons) on mg/kg for i.v. administration (FIG. 1A) and 5.6 mg/kg for p.o. a 1 cc syringe. The Suspension is made the day of use at 10% administration (FIG. 1B) were used. charcoal (100-400 mesh) with 2.5% arabic acid in distilled These time ranging experiments illustrated that 63-maltr water and mixed thoroughly and repeatedly to minimize exol was capable of reversing the centrally mediated antinoci 50 needle obstruction. Animals were sacrificed 30 min after ceptive effects of hydrocodone (FIGS. 1A and 1B), with a administration of the charcoal meal by light ether anesthesia time of peak effect at 90 min for i.v. administration and 120 followed by cervical dislocation. The small intestine (duode min when administered p.o. num to cecum) was dissected out and carefully uncoiled. The Antinociception Studies for Determining Antagonist distance covered by the charcoal was measured and compared Potencies. 55 to the total length of the small intestine for each animal. The Both oral and i.v. potencies were determined by adminis mean percent transit was then calculated as (distance covered tering vehicle or various doses of 6B-maltrexol at appropriate by the charcoal)/(total length of the small intestine)* 100. times prior to an Ago dose of hydrocodone (3.2 mg/kg, i.v.). GI Transit Studies for Determining 6,3-Naltrexol Potency. The respective i.v. and p.o. pretreatment times were 90 min The ability of 6f-naltrexol to block hydrocodone induced (FIG. 2A) and 120 min (FIG. 2B). Mice were tested 10 min 60 GI inhibition was assessed. Both i.v. (FIG. 4A) and oral post hydrocodone injection (time of hydrocodone peak potencies (FIG. 4B) were determined by administering effect) in the 55°C. tail-flickassay. At least three doses were vehicle or various doses of 6f-naltrexol prior to an antinoci tested to produce a dose-response curve. The percent anti ceptive Aso dose of hydrocodone (3.2 mg/kg, i.v.). The pre nociception was then calculated for each dose and compared treatment times corresponded with the time of peak effect for to hydrocodone controls. 65 the antinociception studies. The charcoal meal was given 10 These dose response curves were used to determine IDso min following the injection of hydrocodone. Vehicle (saline) value for 6.f3-maltrexol. The percentage of inhibition or rever controls were also assessed i.v. The percentage of GI transit US 8,883,817 B2 19 20 was calculated for each mouse and a dose-response curve was case of orally co-administered 6B-maltrexol and hydroc constructed for the antagonist. At least three doses were used odone, that therapeutic window occurs when 6f-naltrexol is for each route and the results were compared to Saline and administered to a mouse from 0.1-3.0 mg/kg (FIG. 6C). hydrocodone controls. IDso values were calculated for 6 B-maltrexol to determine 5 TABLE 1 potency to inhibit hydrocodone effects. 6 B-maltrexol and The fold-shift in peripheral vs. central potency was calculated from hydrocodone were administered at appropriate times so that the data presented in FIG. 6A-C and is shown in Table 1 as time of peak effect (as determined in the tail-flick assay) (antinociception IDso)/(GI transit IDso). (A fold-shift less than occurred during charcoal administration. 6B-maltrexol dose 1.0 indicates a greater central potency over peripheral potency. dependently reversed the inhibition of GI transit by hydroc 10 Antinociception odone (Ago dose, i.v.), yielding IDso values of 0.0443 mg/kg Drug GI Transit IDso IDs (95% CI) Fold (95% CI=0.0275-0.0713) and 0.410 (95% CI=0.310-0.543) Combination (95% CI) (mg/kg) (mg/kg) Shift mg/kg for i.v. and p.o. (FIGS. 4A and 4B) administration, respectively. 6B-maltrexol 0.0443 (0.0275-0.0713) 0.222 (0.194-0.253) S.O1 (i.v.). GI Transit Studies for Oral Co-Administration. 15 Hydrocodone Vehicle (saline) or various doses of 6f-naltrexol were (i.v.) orally co-administered with an antinociceptive Aso dose of 6B-maltrexol 0.410 (0.310-0.543) 2.35 (2.11-2.63) 5.73 (p.o.) hydrocodone (32 mg/kg, p.o.) 60 min prior to charcoal Hydrocodone administration (FIG. 5). This time was chosen so that the time (i.v.) of peak effect for the antagonist would occur during intestinal 6B-maltrexol 1.290 (0.990-1.68) 12.3 (10.4-14.7) 9.53 transit of the charcoal meal. Vehicle (saline) controls were (p.o.), also assessed p.o. to compare the observed effects to opioid Hydrocodone naive mice. The percentage of GI transit was calculated for (p.o.) each mouse and a dose-response curve was constructed. At least three doses were used and the results were compared to 25 This therapeutic window is Surprising because it diverges saline and hydrocodone controls. 6B-maltrexol again dose dramatically from the ratios postulated by Simon in United dependently reversed GI inhibition (FIG. 5) with an IDs of States Patent Application 2004/0024006 A1. Our data also 1.290 mg/kg (95% CI=0.990-1.68). demonstrate that use of the dosages postulated by Simon (see Statistical Analysis. United States Patent Application 2004/0024006 A1 at para The dose-response curves shown in FIG. 2-5 were used to 30 graphs 107 and 155) would either have no effect (in the estimate and compare central (antinociception) to peripheral case of paragraph 107) or have the unwanted effect of (GI transit) potencies of 6B-maltrexol. The percentage of inhi reversing antinociception (in the case of paragraph 155). bition or reversal of the hydrocodone effect in either assay The mouse data can be extrapolated to provide for effective was determined for each mouse in the antagonist groups. The formulation for humans. The 0.1-3.0 mg/kg mouse Suggests a percent reversal was calculated as (test-hydrocodone con 35 Human Equivalent Dose (HED) of 0.0081-0.243 mg/kg. This trol)/(saline control-hydrocodone control)* 100. From this calculation is based on a body Surface area calculation pub data an IDs value (and 95% confidence interval) was calcu lished in FDA guidelines for Estimating the Safe Starting lated for each routefantagonist/assay using linear regression Dose in Clinical Trials for Therapeutics in Adult Healthy (FlashCalc software; Dr. Michael Ossipov, University of Ari Volunteers, available on Aug. 16, 2007 at www.fda.gov/cber/ Zona, Tucson, Ariz.). 40 gdlins/dose.htm. If this dose is applied to a 70kilo human, the Potency of 6f-Naltrexol for Slowing GI-Transit and for human subject would need between 0.567-17.0 mg to have Reversing Antinociception. the desired effect of relieving GI transit slowing without Comparison of the calculated potencies (IDs) for 63-nal inhibiting analgesia. A person skilled in the art could predict trexol to reverse either the central effects, antinociception, or and conduct clinical testing to confirm similar pharmacoki peripheral effects, GI-transit slowing, induced by hydroc 45 netics in humans and determine the absolute correct dosage. odone, led to the Surprising discovery that 63-maltrexol is It should be noted that the concentrations required to 5-10-fold more potent peripherally than centrally. FIGS. reverse the antinociceptive effects of hydrocodone are con 6A-C demonstrate this potency difference showing data sistent with the human blood levels of 6f-maltrexol obtained derived from the dose response curves described above. after standard naltrexone treatment for alcohol or opioid 6B-maltrexol was found to have significant shifts in potency 50 addiction maintenance where blocking the central effect is between the two assays for all administration parameters intended. Typically, a minimum dose of 50 mg naltrexone is (FIGS. 6A-C). Both i.v. (FIG. 6A) and p.o. (FIG. 6B) admin administered daily to a human patient. The human must be istration of 6f-naltrexol were approximately 5-times more opioid-free so there are no compounding effects on GI slow potent at reversing GI effects of i.v. hydrocodone than anti ing or drug interactions altering pharmacokinetics or absorp nociceptive effects (Table 1). Furthermore, oral co-adminis 55 tion. The literature teaches that approximately 43% of naltr tration with hydrocodone resulted in a 9.53-fold shift in exone is converted to 6B-maltrexol (for examples, see: Cone, potency (FIG. 6C, Table 1). These data suggest that 6f-nal E. J. Gorodetzky C. W. and Yea SY (1974) “The Urinary trexol is more potent at inhibiting peripheral effects than Excretion Profile of Naltrexone and Metabolites in Man.” central effects induced by opioids. Drug Metab and Disp2(6): 506-512: ReViaTMLabel; Wall M. Calculations of IDso potencies from these data further Sug 60 E., Brine D. R, Perez-Reyes M. (1981) “Metabolism and gest that 6f-naltrexol is 9.5-fold more potent for slowing Disposition of Naltrexone in Man after Oral and Intravenous GI-transit than for reversing antinociception when both drugs Administration, Drug Metabolism and Disposition Drug are administered orally, as would be utilized for therapeutic Metabolism and Disposition, 9(4):369-375; Verebey K. use (Table 1). (1980) “The Clinical Pharmacology of Naltrexone: Pharma These results indicate that there is a therapeutic window of 65 cology and Pharmacodynamics. Naltrexone: NIDA effectiveness for 6 B-maltrexol where peripheral side effects of Research Monograph, 28, RE Willette and G Barnett, eds. pp opioid use are reduced without inhibition of analgesia. In the 147-158: Wall M. E., Brine D. R., Perez-Reyes M. (1980) US 8,883,817 B2 21 22 “The Metabolism of Naltrexone in Man, Naltrexone: NIDA compared to naltrexone in mice, while immediate access is Research Monograph, 28, REWillette and G Barnett, eds. pp considerably less. Opioid agonist half lives in humans are 105-131; Perez-Reyes M. and Wall M. E. (1980) “A Com typically shorter, ~2-6 hours. parative Study of the Oral, Intravenous, and Subcutaneous Administration f3 h-Naltrexone to normal male volunteers.” TABLE 2 Naltrexone: NIDA Research Monograph 28, RE Willette and Concentrations of naltrexone, 63naltrexol and 63-maltrexamide G Barnett, eds. pp. 93-101), meaning humans are exposed to in plasma and brain tissue after i.p. iniection in mice. 20 mg of 6f-naltrexol following such a dose. Given that human dosages are determined for a standard 70 kg person, Plasma concentration Brain concentration 10 (ng/ml) (ng/g) persons are routinely exposed to >0.3 mg 63-maltrexol/kg Time after injection Time after injection body weight daily and often much higher dosages and blood min min levels are utilized. As such, there is evidence that this treat ment level is safe in humans (for examples, see: Dunbar J. L., Injection 10 60 10 60 Turncliff R. Z., Dong Q. Silverman B. L. Ehrich E. W., 15 Naltrexone, 1 mg/kg 54 - 16 4 + 1 69 - 20 9 - 1 Lasseter K. C. (2006) “Single- and Multiple-Dose Pharma 63-Naltrexol, 1 mg/kg 617 24, 28 7 6 9 - 1 6B-Naltrexol, 10 mg/kg 857 - 122 7S 25 89 6 74 - 14 cokinetics of Long-acting Injectable Naltrexone. Alcohol: 63-Naltrexamide, 1 mg/kg 115 - 2 18 - 1 6 - 1 4 + 1 Clin and Exper Res. 30(3):48.0-490; Jayaram-Lindstrom N., 6B-Naltrexamide, 10 mg/kg 933 + 221 166 it 77 27 6 24 1 Wennberg P. Beck O. Franck J. (2005) “An open clinical trial of naltrexone for amphetamine dependence: Compliance and 6(3-Naltrexol--Opioid as a Co-Formulated Product tolerability.” Nord J Pschy 59(3):167-171; Brewer C. and The results in Table 1 and Table 2 indicate that a co Wong V. S. (2004) “Case Report. Naltrexone: report of lack of formulated product containing a specified dose of hydroc hepatotoxicity in acute viral hepatitis, with a review of the odone and 6.3-maltrexol can be created that will effectively literature.” Addict Bio 9, 81-87). treat moderate to severe pain with limited peripheral side Substantially Longer Retention of 6f-Naltrexol and 6 B-Nal 25 trexamide in Plasma and Brain Tissue after i.p Injection in effects such as, but not limited to, constipation, and may Mice Compared to Naltrexone. possibly also reduce nausea and Vomiting. The pain relief would be similar to treatment with hydrocodone alone while Example 3 the peripheral side effects would be much reduced. 30 Moreover, this co-formulation will conferabuse resistance This study shows crude pharmacokinetics of 6f-naltrexol because the central effects of the opioid will be antagonized and 6b-naltrexamide in mouse plasma and brain (thenaltrexol by the 63-maltrexol when doses exceeding those prescribed data were published in Wang et al. 2004; the naltrexamide are taken by any route of administration, including if the data were not published) compared with naltrexone. Mice tablet is manipulated, crushed and injected or Snorted. In the were injected i.p. with 1 mg/kg naltrexone, 1 mg/kg 6B-nal 35 case where doses exceeding those prescribed are taken orally, trexol. 1 mg/kg 6B-maltrexamide, 10 mg/kg 6B-maltrexolor 10 the substantially longer half-life of 6f-naltrexol compared to mg/kg 6 B-maltrexamide and sacrificed after 10 or 60 min. opioid will cause 6f-naltrexol to accumulate to doses that will Blood samples and whole brain were collected. Samples were sufficiently penetrate the CNS to antagonize centrally-medi analyzed for the presence of the antagonists using mass spec ated opioid effects such as pain relief and euphoria. This will trometry. 40 be beneficial in cases of both accidental and intentional over Naltrexone, 6.3-maltrexol and 6.3-maltrexamide were dose. Due to the substantially longer half-life of 6f-maltrexol extracted from plasma or brain tissue homogenates, measured compared to opioid agonists, the effects will become more by liquid chromatography/mass spectrometry/mass spec profound as doses are increased, thus preventing this co trometry (LC/MS/MS), using APCI/positive ionization. Nal formulated product from oral or other abuse as is now com buphine served as the internal standard. The method was 45 mon for opioids. sensitive to ~1 ng/mL (g) (3-4 nM). 6(3-Naltrexol was detect In other words, the substantially longer half-life for the able in plasma but not brain tissue after the naltrexone dose neutral antagonists than of the opioid agonists means the (1.9 ng/mL and 1.7 ng/mL after 10 and 60 min, respectively). neutral antagonist will accumulate. Dosage will therefore be In contrast, no naltrexone was detectable after administration determined such that when steady-state is achieved, there will of 6f-naltrexol. The concentrations of two compounds in 50 be relief of the GI side effects (including possibly nausea and each row of the table represent the injected parent drug only. Vomiting) without impacting pain relief. The co-formulation Mean-SD, n=3. will be made, factoring in a calculation for regular dosing of As shown, similar brain levels were achieved with equipo the opioid, such that the patient or subject will receive the tent doses of naltrexone and 6.3-maltrexol or 6.3-maltrexamide appropriate level of neutral antagonist to relieve GI side (1 mg/kg and 10 mg/kg, respectively). Surprisingly, after 60 55 effects, yet still allow the opioid agonist to relieve pain. Tak min, the levels of 6f-naltrexol and 6(3-maltrexamide had not ing higher than prescribed doses of the co-formulation pre changed from those measured at 10 min, whereas the levels of vents addiction and deters abuse because at higher or multiple maltrexone declined nearly 90% by 60 min. This indicates a doses, the neutral antagonist begins to accumulate and then Substantially longer retention in plasma and particularly in competes with the effects of the opioid, lessoning the pain brain for 6.f3-maltrexol and 6.f3-maltrexamide than for naltrex 60 relief, or, if the formulation is taken for pleasure, the euphoria. one. These data can be extrapolated to Suggest a Substantially In cases where the co-formulation is injected as a form of longer half-life for 6.3-maltrexol and 6.3-maltrexamide than abuse, the higher bioavailability of the antagonist adminis that of opioid agonists Such as naltrexone, in general. In tered directly to the bloodstream will allow antagonism of the humans the half-life of naltrexone is 4 hours, while that of central effects at lower doses. As with oral administration, the 6.3-maltrexolis ~15 hours. Importantly, both 6f-naltrexoland 65 effects will become more profound over time as levels of the 6.3-maltrexamide are much more effectively retained in the antagonist continue to accumulate through repeated dosing brain, Suggesting a much longer effective duration of action due to the limited half-life of the opioid. Yet, because 6 B-nal US 8,883,817 B2 23 24 trexol is a neutral antagonist, these effects will manifest with Effect of 6B-Naltrexamide on Hydrocodone-Induced Gas out, or with Substantially less, precipitating withdrawal, pro trointestinal Tract Slowing viding an effective means for preventing misuse. See Sadee and Simon. Example 5 Effect of 6f-Naltrexamide on Hydrocodone-Induced Anti nociception GI Transit Assay Example 4 Opioid-induced GI transit inhibition was measured using standard protocols as described above under Example 2. Tail Flick Assay 10 GI Transit Studies for Determining 6?-Naltrexamide Potency. The tail-flickassay was used to measure antinociception as The ability of 6f-naltrexamide to block hydrocodone described above under Example 1. induced GI inhibition was assessed. Both i.v. (FIG. 10A) and Antinociception Studies for Determining Time of Peak oral potencies (FIG. 10B) were determined by administering 15 vehicle or various doses of 6B-maltrexamide prior to an anti Effect of 6,3-Naltrexamide. nociceptive Aso dose of hydrocodone (3.2 mg/kg, i.v.). The The duration of 6f-naltrexamide effects were measured by pretreatment times corresponded with the time of peak effect pretreating mice with 6B-maltrexamide at various times prior for the antinociception studies. The charcoal meal was given to an injection of an antinociceptive Aso dose of hydrocodone 10 min following the injection of hydrocodone. Vehicle (sa (3.2 mg/kg, i.v. dose determined previously; data not shown). line) controls were also assessed i.v. The percentage of GI Mice were then tested 10 min later, at time of peak effect for transit was calculated for each mouse and a dose-response hydrocodone, in the tail-flickassay. 6B-maltrexamide doses of curve was constructed for the antagonist. At least three doses 10 mg/kg (FIG. 7A) and 56 mg/kg (FIG.7B) were used for i.v. were used for each route and the results were compared to and p.o. administration, respectively. saline and hydrocodone controls. These time ranging experiments illustrated that 63-maltr 25 IDso values were calculated for 6 B-maltrexamide to deter examide was capable of reversing the centrally mediated mine potency to inhibit hydrocodone effects. 6(3-maltrexam antinociceptive effects of hydrocodone (FIGS. 7A and 7B). ide and hydrocodone were administered at appropriate times with a time of peak effect at 120 min for i.v. administration so that time of peak effect (as determined in the tail-flick and 120-180 min when administered p.o. assay) occurred during charcoal administration. When given Antinociception Studies for Determining Antagonist 30 i.V. (FIG. 10A) and p.o. (FIG. 10B) 6.3-maltrexamide dose Potencies. dependently reversed the inhibition of GI transit by hydroc Both oral and i.v. potencies were determined by adminis odone (Aso dose, i.v.), yielding IDso values of 0.173 (95% tering vehicle or various doses of 6B-maltrexamide at appro CI=0.131-0.230) and 1.92 (95% CI=1.03-3.56) for i.v. and priate times prior to an Ago dose of hydrocodone (3.2 mg/kg, p.o. administration, respectively. i.v.). The respective i.v. (FIG. 8A) and p.o. (FIG.8B) pretreat 35 GI Transit Studies for Oral Co-Administration. ment times were 120 min. Mice were tested 10 min post Vehicle (saline) or various doses of 6f-naltrexamide are hydrocodone injection (time of hydrocodone peak effect) in orally co-administered with an antinociceptive Aso dose of the 55° C. tail-flick assay. At least three doses were tested to hydrocodone (32 mg/kg, p.o.) 60 min prior to charcoal produce a dose-response curve. The percent antinociception administration. This time is chosen so that the time of peak was then calculated for each dose and compared to hydroc 40 effect for the antagonist will occur during the intestinal transit odone controls. of the charcoal meal. Vehicle (saline) controls are also These dose response curves were used to determine IDso assessed p.o. to compare the observed effects to opioid naive value for 6.3-maltrexamide. The percentage of inhibition, or mice. The percentage of GI transit is calculated for each reversal of the hydrocodone-induced antinociception, was mouse and a dose-response curve is constructed. At least calculated as (test-hydrocodone control)/(Saline control-hy 45 three doses are used for each antagonist and the results are drocodone control)*100. From this data an IDs value (and compared to Saline and hydrocodone controls. 95% confidence interval) was calculated for each route using When given i.v. and p.o., 6B-maltrexamide is expected to linear regression (FlashCalc software; Dr. Michael Ossipov, dose-dependently reverse the inhibition of GI transit by University of Arizona, Tucson, Ariz.). IDs values for 6f-nal hydrocodone and other analgesics with an IDs in the range of trexamide inhibition of hydrocodone-induced antinocicep 50 0.1 to 0.2 mg/kg and 1 to 2 mg/kg for i.v. and p.o. adminis tion were determined to be 4.06 mg/kg (95% CI=3.27-5.04) tration, respectively. for i.v. administration, and 27.4 (22.6-33.2) for oral adminis Statistical Analysis. tration. The dose-response curves shown in FIG.7-10 were used to Antinociception Studies for Oral Co-Administration. estimate and compare central (antinociception) to peripheral The tail-flick assay was used to construct full dose- and 55 (GI transit) potencies of 6f-naltrexamide. The percentage of time-response Summaries for 6B-maltrexamide in combina inhibition or reversal of the hydrocodone effect in either assay tion with hydrocodone. Vehicle or various doses of antagonist was determined for each mouse in the 6f-naltrexamide were orally co-administered with an Ago dose of hydrocodone groups. The percent reversal was calculated as (test-hydroc (32 mg/kg, p.o.) determined previously (data not shown). odone control)/(saline control-hydrocodone control)* 100. Tail-flick latencies were determined at t=10, 20, 30, 45, 60, 60 From this data an IDso value (and 95% confidence interval) 90, 120 and 180 minutes post injection (or until 20% MPE was calculated for each routefantagonist/assay using linear was reached) and % antinociception was calculated for each regression (FlashCalc software; Dr. Michael Ossipov, Uni mouse (FIG. 9). versity of Arizona, Tucson, Ariz.). The experiments shown in FIG. 7-9 demonstrate that Potency of 6f-Naltrexamide for Slowing GI-Transit and for 6B-maltrexamide blocks hydrocodone-induced antinocicep 65 Reversing Antinociception. tion regardless of the route of administration, with a potency Comparison of the calculated potencies (ID50) for 6.f3-nal approximately 10-fold lower than that of 6f-naltrexol. trexamide to reverse either the central effects, antinocicep US 8,883,817 B2 25 26 tion, or peripheral effects, GI-transit slowing, induced by hydrocodone in the tail-flickassay. Naltrexone doses of 0.10 hydrocodone, led to the Surprising discovery that 6B-maltr mg/kg for i.V. (FIG. 12A) and 0.56 mg/kg for p.o. (FIG. 12B) examide is 14-25-fold more potent peripherally than cen were used. trally. FIGS. 11A and B demonstrate this potency difference These time ranging experiments illustrate that naltrexone showing data derived from the dose response curves was capable of reversing the centrally mediated antinocicep described above. tive effects of hydrocodone (FIGS. 13A and 13B), with a time 6B-maltrexamide was found to have significant shifts in of peak effect at 30 min for i.v. administration and 45 min potency between the two assays for all injection parameters. when administered p.o. I.V. (FIG. 11A, Table 3) administration of 6f-naltrexamide was approximately 23-times more potent at reversing GI 10 Antinociception Studies for Determining Antagonist effects of i.v. hydrocodone than antinociceptive effects while Potencies. orally administered 6f-naltrexamide demonstrated 14-fold Both oral and i.v. potencies were determined by adminis more potency for reversing GI effects compared to antinoci tering vehicle or various doses of naltrexone at appropriate ceptive effects (FIG. 11B, Table 3). These data suggest that times prior to an Ago dose of hydrocodone (3.2 mg/kg, i.v.). 6B-maltrexamide is significantly more potent at inhibiting the 15 The respective i.v. (FIG. 13A) and p.o. (FIG. 13B) pretreat peripheral effects than the central effects induced by opioids. ment times were 30 and 45 min. Mice were tested 10 min post Furthermore, oral co-administration with hydrocodone is hydrocodone injection (time of hydrocodone peak effect) in expected to show a 10-25-fold and potentially up to a 50-fold the 55° C. tail-flick assay. At least three doses were tested to shift in potency as well. produce a dose-response curve. The percent antinociception Thus, it is anticipated that 6f-naltrexamide will be 10-25 was then calculated for each dose and compared to hydroc fold, and potentially 50-fold, more potent for slowing GI odone controls. transit than for reversing antinociception when both drugs are These dose response curves were used to determine IDso administered orally, so could be utilized for therapeutic use. value for naltrexone in these experiments for comparison The 6f-maltrexamide exhibited a much larger potency shift 25 purposes. The percentage of inhibition or reversal of the than predicted from its chemical structure, Suggesting that hydrocodone-induced antinociception was calculated as 6B-maltrexamide may be actively prevented from entering, or (test-hydrocodone control)/(Saline control-hydrocodone is transported out of the CNS compared to 6.3-maltrexol, and control)* 100. From this data an IDso value (and 95% confi thus may provide a larger therapeutic window than 6B-maltr dence interval) was calculated for each route using linear exol. 30 regression (FlashCalc software; Dr. Michael Ossipov, Uni versity of Arizona, Tucson, Ariz.). IDso values for naltrexone TABLE 3 inhibition of hydrocodone-induced antinociception were The fold-shift in peripheral vs. central potency was calculated and determined to be 0.0411 (0.0319-0.0529) for i.v. administra is shown as (antinociception IDso)f(GI transit IDso). A fold-shift 35 tion, and 0.534 (0.47 1-0.605) for oral administration. These less than 1.0 indicates a greater central potency over peripheral values are consistent with published values for the oral bio potency. availability of naltrexone and with the published observation Antinociception that 6f-naltrexol is approximately 5-10-fold less potent than GI Transit IDso IDso (95% Fold maltrexone for reversing morphine-induced antinociception Drug Combination (95% CI) (mg/kg) CI) (mg/kg) Shift 40 (Wang D. Raehal K.M., Lin E.T., Lowery J.J., Kieffer B. L., 6B-maltrexamide (i.v.), 0.173 (0.131-0.230) 4.06 (3.27-5.04) 23.5 Bilsky E. J., Sadee W. (2004 February Epub 2003 Nov. 4) Hydrocodone (i.v.) “Basal signaling activity of mu opioid receptor in mouse 6B-maltrexamide (p.o.), 1.92 (1.03-3.56) 27.4 (22.6-33.2) 14.3 Hydrocodone (i.v.) brain: role in narcotic dependence. J Pharmacol Exp Ther: 63-maltrexamide (p.o.), 1-2 3-5 10-50 308(2):512-20; Raehal K. M., Lowery J. J., Bhamidipati C. Hydrocodone (p.o.)* 45 M., Paolino R. M., Blair J. R., Wang D., Sadee W., Bilsky E. Predicted J. (2005 June: Epub 2005 Feb. 16), depending on route of administration. Effect of Naltrexone, a Well-Known and Characterized Antinociception Studies for Oral Co-Administration. Antagonist, on Hydrocodone-Induced Antinociception. 50 The tail-flick assay was used to construct full dose- and Experiments with naltrexone illustrate the significant dif time-response Summaries for naltrexone in combination with ferences between the compounds taught by this application hydrocodone. Vehicle or various doses of antagonist were and known, characterized antagonists. orally co-administered with an Ago dose of hydrocodone (32 Example 6 mg/kg, p.o.) determined previously (data not shown). Tail 55 flick latencies were determined at t=10, 20, 30, 45, 60,90, 120 Tail Flick Assay and 180 minutes post injection (or until 20% MPE was reached) and % antinociception was calculated for each The tail-flickassay was used to measure antinociception as mouse (FIG. 15). described above under Example 1. 60 The antinociception experiments shown in FIG. 14 yield an Antinociception Studies for Determining Time of Peak IDso value of 0.914 mg/kg (95% CI=3.27-5.04) for naltrex Effect of Naltrexone. one co-administered with hydrocodone. The duration of naltrexone effects were measured by pre The experiments shown in FIG. 12-14 demonstrate that treating mice with naltrexone at various times prior to an maltrexone blocks hydrocodone-induced antinociception injection of an antinociceptive Ago dose of hydrocodone (3.2 65 regardless of the route of administration, consistent with the mg/kg, i.V., dose determined previously; data not shown). many published reports on naltrexone and its clinical use for Mice were tested 10 min later at time of peak effect for the treatment of alcoholism and opioid addiction. US 8,883,817 B2 27 28 Effect of Naltrexone on Hydrocodone-Induced Gastrointes FIG. 17A-B illustrate the potency differences showing data tinal Tract Slowing derived from the dose response curves described above. Naltrexone was found to have small or negligible shifts in Example 7 potency between the two assays for all injection parameters. I.V. (FIG. 17A, Table 4) administration of naltrexone was GI Transit Assay approximately equipotent at reversing GI effects of i.v. hydrocodone than antinociceptive effects while orally admin Opioid-induced GI transit inhibition was measured using istered naltrexone demonstrated only a 3-fold difference in standard protocols as described above under Example 2. potency for reversing GI effects compared to antinociceptive GI Transit Studies for Determining Naltrexone Potency. 10 effects (FIG. 17B, Table 4). Furthermore, oral co-administra The ability of naltrexone to block hydrocodone-induced GI tion with hydrocodone resulted in a 0.6-fold shift in potency, inhibition was assessed. Both i.v. (FIG. 15A) and oral poten actually exhibiting more central than peripheral potency cies (FIG.15B) were determined by administering vehicle or (FIG. 17C, Table 4). These data suggest that naltrexone is various doses of naltrexone prior to an antinociceptive Ago nearly equipotent for inhibiting peripheral effects and central dose of hydrocodone (3.2 mg/kg, i.v.). The pretreatment 15 effects induced by opioids, consistent with its medicinal use times corresponded with the time of peak effect for the anti as a treatment for alcoholism and opioid addiction. nociception studies. The charcoal meal was given 10 min following the injection of hydrocodone. Vehicle (saline) con TABLE 4 trols were also assessed i.v. The percentage of GI transit was The fold-shift in peripheral vs. central potency was calculated and is shown in Table 4 as (antinociception IDso)f(GI transit IDso). A calculated for each mouse and a dose-response curve was fold-shift less than 1.0 indicates a greater central potency over constructed. At least three doses were used for each route and peripheral potency. the results were compared to Saline and hydrocodone con trols. Antinociception Drug GI Transit IDso IDso (95% CI) Fold IDso values were calculated for naltrexone to determine 25 (mg/kg) Shift potency to inhibit hydrocodone effects. Naltrexone and Combination (95% CI) (mg/kg) hydrocodone were administered at appropriate times so that Naltrexone 0.0456 (0.0275-0.0757) 0.0411 (0.0319-0.0529) O.901 (i.v.). time of peak effect (as determined in the tail-flick assay) Hydro occurred during charcoal administration. When given by i.v. codone (FIG. 15a) and p.o. (FIG. 15b) naltrexone dose-dependently 30 (i.v.) Naltrexone 0.194 (0.136-0.277) 0.534 (0.47 1-0.605) 2.75 reversed the inhibition of GI transit by hydrocodone (Aso (p.o.), dose, i.v.), yielding IDs values of 0.0456 (95% CI=0.0275 Hydro 0.0757) for i.v. and 0.194 (95% CI=0.136-0.277) for p.o. codone administration, respectively. (i.v.) GI Transit Studies for Oral Co-Administration. 35 Naltrexone 1.40 (1.07-1.84) 0.914 (0.628–1.33) O.653 (p.o.), Vehicle (saline) or various doses of naltrexone was orally Hydro co-administered with an antinociceptive Ago dose of hydroc codone odone (32 mg/kg, p.o.) 15 min prior to charcoal administra (p.o.) tion (FIG. 16). This time was chosen so that the time of peak effect for the antagonist would occur during the GI transit of 40 These data illustrate the difference in activity between the charcoal meal. Vehicle (saline) controls were also known, clinically used antagonists and the novel activities of assessed p.o. to compare the observed effects to opioid naive the neutral antagonists taught in this application. mice. The percentage of GI transit was calculated for each Moreover, a strong induction of diarrhea was present with mouse and a dose-response curve was constructed. At least administration of naltrexone, but was absent with naltrexol three doses were used for each antagonistand the results were 45 compared to Saline and hydrocodone controls. and naltrexamide. Naltrexone orally co-administered with hydrocodone (Aso What is claimed is: dose, p.o.) again dose-dependently reversed GI inhibition 1. A unit dosage of an analgesic composition comprising: (FIG. 16) with an IDs of 1.40 mg/kg (95% CI -1.07-1.84). an opioid agonist in an amount Sufficient to confer analge Statistical Analysis. 50 sia in a mammalian Subject; and The dose-response curves shown in FIG. 13-16 were used a neutral opioid antagonist in an amount Sufficient to Sub to estimate and compare central (antinociception) to periph stantially inhibit peripheral effects, and insufficient to eral (GI transit) potencies for naltrexone. The percentage of block Substantial central effects, of the opioid agonist in inhibition or reversal of the hydrocodone effect in either assay the Subject, wherein the agonist and antagonist are was determined for each mouse in the naltrexone groups. The 55 selected so that a ratio of antinociception ID50 to GI percent reversal was calculated as (test-hydrocodone con transit ID50 for the agonistand the antagonist is between trol)/(saline control-hydrocodone control)* 100. From this about 5 and about 50. data an IDs value (and 95% confidence interval) was calcu 2. A unit dosage of analgesic composition according to lated for each routefantagonist/assay using linear regression claim 1, wherein the opioid agonist is selected from the group (FlashCalc software; Dr. Michael Ossipov, University of Ari 60 consisting of alfentanil, allylprodine, alphaprodine, anileri Zona, Tucson, Ariz.). dine, benzylmorphine, bezitramide, buprenorphine, butor Potency of Naltrexone for Slowing GI-Transit and for phanol, clonitaZene, codeine, desomorphine, dextromora Reversing Antinociception. mide, dezocine, diampromide, diamorphone, Comparison of the calculated potencies (IDso) for naltrex dihydrocodeine, dihydromorphine, dimenoxadol, dimephep one to reverse either the central effects, antinociception, or 65 tanol, dimethylthiambutene, dioxaphetyl butyrate, dipi peripheral effects, GI-transit slowing, demonstrated that nal panone, eptazocine, ethoheptazine, ethylmethylthiambutene, trexone was nearly equipotent peripherally and centrally. ethylmorphine, etonitaZene, fentanyl, heroin, hydrocodone, US 8,883,817 B2 29 30 hydromorphone, hydroxypethidine, isomethadone, ketobe -continued midone, levorphanol, levophenacylmorphan, lofentanil, (IB) meperidine, meptazinol, metazocine, methadone, metopon, R12

morphine, myrophine, narceline, nicomorphine, norlevorpha nol, normethadone, noroxycodone, nalorphine, nalbuphene, normorphine, norpipanone, opium, oxycodone, oxymor phone, papavereturn, pentazocine, phenadoxone, phenomor phan, phenazocine, phenoperidine, piminodine, piritramide, propheptazine, promedol, properidine, propoxyphene, Sufen tanil, tilidine and tramadol. 10 '' X2 3. A unit dosage of an analgesic composition according to RO ON XI claim 2, wherein the Subject is a human. 4. A unit dosage of an analgesic composition according to wherein: claim 3, Such composition being Suitable for oral, peroral, 15 R" is C-C (cycloalkyl)(alkyl) or Cs-C, (cycloalkenyl) intragastric, Sublingual, Suppository, or intravenous adminis alkyl: tration. R’ is H, OH or esters thereof; 5. A unit dosage according to claim 4, wherein the neutral R is H, alkyl or C-C alkyl-C=O; opioid antagonist has a blood half-life Substantially longer R" and Rare independently H, halogen, C-C alkyl, than the blood half-life of the opioid agonist, so that repeated C-C alkoxy, nitro, amino, cyano, carboxyl or acyl administration of the dosage or administration above a pre which may be substituted for one or more hydrogens scribed dosage causes a greater increase in blood concentra on the ring: tion of the antagonist than of the agonist, so as to deter X' and X’ are the same ordifferent, and may be H, alkyl, diversion, discourage abuse and/or reduce addiction liability OR, NR7RR, NCOR, NO, or SR'', to the agonist resulting from Such administration. 25 wherein, 6. A unit dosage according to claim 4, wherein the neutral RandR'' are independently H, alkyl, substituted alkyl, opioid antagonist and/or agonist are Suitable for formulation cycloalkyl, substituted cycloalkyl, aryl, substituted in a slow-release formulation, slow-release co-formulation, aryl, acyl, aroyl, polyethyleneglycyl (PEGyl) or a or are formulated in a slow-release formulation or co-formu polyether group; lation, either separately or together. 30 R. RandR'' are independently hydrogen, alkyl, sub 7. A unit dosage of an analgesic composition according to stituted alkyl, cycloalkyl, Substituted cycloalkyl, aryl, claim 1 wherein the opioid agonist is hydrocodone. or substituted aryl; 8. A unit dosage according to claim 1 that deters abuse of R and R' can be present or absent and are indepen the opioid agonist, wherein the opioid agonist has a blood 35 dently hydrogen, alkyl, Substituted alkyl, cycloalkyl, half-life; and the neutral opioid antagonist has a blood half substituted cycloalkyl, aryl, or substituted aryl or life substantially longer than the blood half-life of the opioid pharmaceutically acceptable salts thereof. agonistand is also present in an amount effective so that, upon 11. A unit dosage according to claim 1, wherein the opioid Successive administration of the unit dosage, the blood con antagonist is a naloxone analog represented by formula IC or centration ratio of neutral opioid antagonist to opioid agonist 40 If: increases with each Successive administration until a steady state is reached, as measured in mg per kg of body weight of the Subject, and repeated administration of the unit dosage (IC) exceeding therapeutically recommended limits results in

reduced euphoria and reduced pain relief in the Subject so as 45 to deter abuse. 9. A pharmaceutical composition according to claim 8. wherein the neutral opioid antagonist and/or agonist are Suit able for formulation in a slow-release formulation, slow release co-formulation, or are formulated in a slow-release formulation or co-formulation, either separately or together. 50 10. A unit dosage according to claim 1, wherein the opioid antagonist is a naltrexone analog represented by formula ICl. or IB: (IB)

55 (IC)

65 wherein: R" is C-C alkenyl: R’ is H, OH or esters thereof; US 8,883,817 B2 31 32 R is H, alkyl or C-C alkyl-C=O; release co-formulation, or are formulated in a slow-release R" and Rare independently H, halogen, C-C alkyl, formulation or co-formulation, either separately or together. C-C alkoxy, nitro, amino, cyano, carboxyl or acyl 19. A unit dosage according to claim 16, wherein the neu which may be substituted for one or more hydrogens tral opioid antagonist and/or agonist are Suitable for formu on the ring: lation in a slow-release formulation, slow-release co-formu X' and X’ are the same or different, and may be H, alkyl, lation, or are formulated in a slow-release formulation or OR, NR7RR, NCOR, NO, or SR'', co-formulation, either separately or together. wherein, 20. A unit dosage of an analgesic composition comprising: RandR'' are independently H, alkyl, substituted alkyl, an opioid agonist in an amount Sufficient to confer analge cycloalkyl, substituted cycloalkyl, aryl, substituted 10 sia in a mammalian Subject; and aryl, acyl, aroyl, polyethyleneglycyl (PEGyl) or a a neutral opioid antagonist in an amount Sufficient to pro polyether group; duce nearly complete inhibition of peripheral effects, R. RandR'' are independently hydrogen, alkyl, sub and insufficient to block substantial central effects, of stituted alkyl, cycloalkyl, Substituted cycloalkyl, aryl, the opioid agonist in the Subject. or substituted aryl; 15 21. A unit dosage of an analgesic composition according to R and R' can be present or absent and are independently claim 20, wherein the subject is a human. hydrogen, alkyl, Substituted alkyl, cycloalkyl, Substi 22. A unit dosage of an analgesic composition according to tuted cycloalkyl, aryl, or Substituted aryl or pharmaceu claim 20, wherein the opioid agonist is hydrocodone. tically acceptable salts thereof. 23. A unit dosage according to claim 20 that deters abuse of 12. A unit dosage according to claim 1, wherein the neutral the opioid agonist, wherein the opioid agonist has a blood opioid antagonist is selected from the group consisting of half-life; and the neutral opioid antagonist has a blood half 6B-maltrexamide, a pharmaceutically acceptable isomorph life substantially longer than the blood half-life of the opioid thereof, and a pharmaceutically acceptable salt thereof. agonistand is also presentinanamount effective so that, upon 13. A unit dosage according to claim 1, wherein the neutral Successive administration of the unit dosage, the blood con opioid antagonist is selected from the group consisting of 25 centration ratio of neutral opioid antagonist to opioid agonist 6B-maltrexol, a pharmaceutically acceptable isomorph increases with each Successive administration until a steady thereof, and a pharmaceutically acceptable salt thereof. state is reached, as measured in mg per kg of body weight of 14. A composition according to claim 1, wherein the neu the Subject, and repeated administration of the unit dosage tral opioid antagonist is 6B-maltrexol present in an amount exceeding therapeutically recommended limits results in between about 0.008-0.25 mg/kg of body weight of the sub 30 reduced euphoria and reduced pain relief in the Subject so as ject and the opioid agonist is a therapeutically effective to deter abuse. amount of hydrocodone. 24. A unit dosage according to claim 20, wherein the opioid 15. A unit dosage of analgesic composition according to antagonist is a naltrexone analog represented by formula ICl. claim 1, wherein the opioid agonist is selected from the group or IB: consisting of alfentanil, allylprodine, alphaprodine, anilleri 35 dine, benzylmorphine, bezitramide, buprenorphine, butor phanol, clonitaZene, codeine, desomorphine, dextromora (IC) mide, dezocine, diampromide, diamorphone, dihydrocodeine, dihydromorphine, dimenoxadol, dimephep tanol, dimethylthiambutene, dioxaphetyl butyrate, dipi 40 panone, eptazocine, ethoheptazine, ethylmethylthiambutene, ethylmorphine, etonitaZene, fentanyl, heroin, hydrocodone, hydromorphone, hydroxypethidine, isomethadone, ketobe midone, levorphanol, levophenacylmorphan, lofentanil, meperidine, meptazinol, metazocine, methadone, metopon, 45 morphine, myrophine, narceline, nicomorphine, norlevorpha nol, normethadone, noroxycodone, nalorphine, nalbuphene, (IB) normorphine, norpipanone, opium, oxycodone, oxymor phone, papavereturn, pentazocine, phenadoxone, phenomor phan, phenazocine, phenoperidine, piminodine, piritramide, 50 propheptazine, promedol, properidine, propoxyphene, Sufen tanil, tilidine and tramadol. 16. A unit dosage of an analgesic composition according to claim 15. Such composition being suitable for oral, peroral, intragastric, Sublingual, Suppository, or intravenous adminis 55 tration. 17. A unit dosage according to claim 16, wherein the neu tral opioid antagonist has a blood half-life substantially longer than the blood half-life of the opioid agonist, so that wherein: repeated administration of the dosage or administration 60 R" is C-C (cycloalkyl)(alkyl) or Cs-C, (cycloalkenyl) above a prescribed dosage causes a greater increase in blood alkyl: concentration of the antagonist than of the agonist, so as to R’ is H, OH or esters thereof; deter diversion, discourage abuse and/or reduce addiction R is H, alkyl or C-C alkyl-C=O; liability to the agonist resulting from Such administration. R" and Rare independently H, halogen, C-C alkyl, 18. A pharmaceutical composition according to claim 17. 65 C-C alkoxy, nitro, amino, cyano, carboxyl or acyl wherein the neutral opioid antagonist and/or agonist are Suit which may be substituted for one or more hydrogens able for formulation in a slow-release formulation, slow on the ring: US 8,883,817 B2 33 34 X' and X’ are the same or different, and may be H, alkyl, wherein: -OR- NRRR, NCOR, NO, or SR'', R" is C-C alkenyl: wherein, RandR'' are independently H, alkyl, substituted alkyl, R’ is H, OH or esters thereof; cycloalkyl, substituted cycloalkyl, aryl, substituted 5 R is H, alkyl or C-C alkyl-C=O; aryl, acyl, aroyl, polyethyleneglycyl (PEGyl) or a R" and Rare independently H, halogen, C-C alkyl, polyether group; C-C alkoxy, nitro, amino, cyano, carboxyl or acyl R. RandR'' are independently hydrogen, alkyl, sub which may be substituted for one or more hydrogens stituted alkyl, cycloalkyl, Substituted cycloalkyl, aryl, on the ring: or substituted aryl; 10 R and R' can be present or absent and are indepen X' and X’ are the same or different, and may be H, alkyl, dently hydrogen, alkyl, Substituted alkyl, cycloalkyl, OR, NR7RR, NCOR, NO, or SR'', substituted cycloalkyl, aryl, or substituted aryl or wherein, pharmaceutically acceptable salts thereof. RandR'' are independently H, alkyl, substituted alkyl, 25. A unit dosage according to claim 20, wherein the opioid 15 cycloalkyl, substituted cycloalkyl, aryl, substituted antagonist is a naloxone analog represented by formula IC or aryl, acyl, aroyl, polyethyleneglycyl (PEGyl) or a IB: polyether group; R. RandR'' are independently hydrogen, alkyl, sub (IC) stituted alkyl, cycloalkyl, Substituted cycloalkyl, aryl, or substituted aryl; Rand R' can be present or absent and are independently hydrogen, alkyl, Substituted alkyl, cycloalkyl, Substi 25 tuted cycloalkyl, aryl, or Substituted aryl or pharmaceu tically acceptable salts thereof. 26. A unit dosage according to claim 20, wherein the neu tral opioid antagonist is selected from the group consisting of 6B-maltrexamide, a pharmaceutically acceptable isomorph (IB) 30 thereof, and a pharmaceutically acceptable salt thereof. 27. A unit dosage according to claim 20, wherein the neu tral opioid antagonist is selected from the group consisting of 6B-maltrexol, a pharmaceutically acceptable isomorph 35 thereof, and a pharmaceutically acceptable salt thereof. 28. A composition according to claim 20, wherein the neutral opioidantagonist is 6B-maltrexol present in an amount between about 0.008-0.25 mg/kg of body weight of the sub ject and the opioid agonist is a therapeutically effective 40 amount of hydrocodone. k k k k k UNI TED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. : 8,883,817 B2 Page 1 of 1 APPLICATIONNO. : 12/288347 DATED : November 11, 2014 INVENTOR(S) : Wolfgang Sadée et al. It is certified that error appears in the above-identified patent and that said Letters Patent is hereby corrected as shown below:

IN THE CLAIMS

In Col. 29, line 7 replace “papavereturn s with “papaveretum

In Col. 31, line 49 replace “papavereturn s with “papaveretum

In Col. 33, line 2 replace “OR” with “OR”

Signed and Sealed this Fifteenth Day of March, 2016 74-4-04- 2% 4 Michelle K. Lee Director of the United States Patent and Trademark Office