US 2006O198886A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2006/0198886 A1 Jenkins (43) Pub. Date: Sep. 7, 2006 (54) MEDICAMENT HAVING COATED Publication Classification METHENAMINE COMBINED WITH ACDFER (51) Int. Cl. A6IR 9/22 (2006.01) (76) Inventor: Richard B. Jenkins, Tampa, FL (US) A6II 3L/205 (2006.01) A6II 38/04 (2006.01) Correspondence Address: (52) U.S. Cl. ............................. 424/468; 514/19; 514/554 WYATT BARTON PRATT 15 COLUMBIAAVENUE HOPEWELL, NJ 08525 (US) (57) ABSTRACT (21) Appl. No.: 11/068,712 A Solid pharmaceutical medicament has a coated meth (22) Filed: Mar. 1, 2005 enamine compound in combination with an urinary acidifier. US 2006/019888.6 A1 Sep. 7, 2006 MEDCAMENT HAVING COATED 0010 When used herein, the terms active agent, active METHENAMINE COMBINED WITH ACIDFER pharmaceutical ingredient, pharmaceutical actives, API. active compound, therapeutic agent, therapeutic ingredient, BACKGROUND OF THE INVENTION therapeutic compound and other like terms are used inter 0001) 1. Field of the Invention changeably and include salts and other pharmaceutical forms of the detailed compounds. 0002 The present invention pertains to solid pharmaceu tical combinations of a coated methenamine compound 0011. The methenamine compounds of the present inven combined with an acidifier. tion include methenamine, pharmaceutically acceptable 0003 2. Brief Description of the Related Art salts of methenamine and combinations thereof. Salts of the present invention include those refers to derivatives of the 0004 Methenamine, also known as hexamethylenetetra methenamine having the therapeutic compound modified by mine or HMTA, is a compound useful in the treatment of reacting it with an acid or base as needed to form an ionically urinary infections. Typically, the methenamine mandelate is bound pair. Examples of pharmaceutically acceptable salts administered with sodium acid phosphate monohydrate to include conventional non-toxic salts or the quaternary increase the formation of formaldehyde from hydrolysis of ammonium salts of the parent compound formed, for the methenamine mandelate in the urine to impart an anti septic effect. At a pH of 6.0 or above, and particularly in an example, from non-toxic inorganic or organic acids. Suitable alkaline medium, methenamine is devoid of antiseptic non-toxic salts include those derived from inorganic acids action. Such as hydrochloric, hydrobromic, Sulfuric, Sulfonic, Sul famic, phosphoric, nitric and others known to those of 0005 Methenamine has a wide spectrum bacteriacidal ordinary skill in the art. The salts prepared from organic and bacteriostatic activity and low toxicity, however, it acids such as amino acids, acetic, propionic, succinic, gly requires a constant acidic urine to induce the continuous colic, Stearic, lactic, malic, tartaric, citric, ascorbic, pamoic, yield of formaldehyde. The separate concomitant adminis maleic, hydroxymaleic, phenylacetic, glutamic, benzoic, tration of an acidifying agent for urine necessitates frequent salicylic, Sulfanilic, 2-acetoxybenzoic, fumaric, toluene pH assays of the urine and a constant reminder to the patient Sulfonic, methanesulfonic, ethane disulfonic, oxalic, to take the second, acidifying agent. This results in a isethionic, and others known to those of ordinary skill in the haphazard coadministration of the acidifying agent along art. The pharmaceutically acceptable salts of the present with the methenamine. invention can be synthesized from the parent therapeutic 0006 There is a need in the art to provide improved compound which contains a basic or acidic moiety by pharmaceutical formulations of methenamine compounds as conventional chemical methods. Salts of methenamine an antiseptic agent. The present invention addresses this and include combinations, condensation products or other salt other needs. formations of methenamine, as known in the art, such as tannin (as disclosed in U.S. Pat. No. 607,172 to Hock), SUMMARY OF THE INVENTION quinic acid (as disclosed in U.S. Pat. No. 690,804 to Wichmann et al.), sodium acetate double salt (as disclosed 0007. The present invention includes a solid pharmaceu in U.S. Pat. No. 852,993 to Bergell), mandelic acid (as tical medicament comprising a coated methenamine com disclosed in U.S. Pat. No. 2,124.321 to Tisza), aromatic pound effective to delay release of the methenamine within acids (as disclosed in U.S. Pat. No. 2,179,618 to Edelman et the gastrointestinal tract, particularly after passage through al.), benzene monocarboxylic acids (as disclosed U.S. Pat. the stomach, in combination with an acidifier effective for No. 2,912,435 to Scholz), hydroxamate compounds such as acidifying urine to a pH of from about 6 or less. The acetohydroxamic acid (see e.g., U.S. Pat. No. 4,146,644 to medicament may be administered in unit dosage form. Griffith et al.), methenamine mandelate, hexamethylenetet Additionally, the medicament may include a second active ramine hippurate (see e.g., U.S. Pat. No. 3,004,026 to Galat), pharmaceutical ingredient such as an antiseptic agent. and/or specialized enantiomorph forms (see e.g., U.S. Pat. 0008. The present invention also includes a method for No. 4,001.231 to Diamond) and the like. Preferred meth urinary antiseptic treatment comprising the steps of provid enamine compounds include methenamine, methenamine ing the previously described medicament and dosing a mandelate, methenamine hippurate and combinations patient with the medicament. thereof, with methenamine mandelate most preferred. 0012. The medicament of the present invention includes DETAILED DESCRIPTION OF THE an appropriate amount of methenamine compound, gener INVENTION ally having an amount that is therapeutically effective in a 0009. The present invention includes a solid pharmaceu convenient dosage unit for a given patient. Preferred tical medicament having a coated active pharmaceutical amounts of methenamine compound contained within the ingredient of a methenamine compound in combination with pharmaceutical formulation of the present invention may be an acidifier that is effective to acidify the urine of a patient administered, for example without limitation, in unit dos to a pH of from about 6 or less. By separately coating the ages with typical dosing amounts of the methenamine com methenamine, the present invention provides a vehicle to pound ranging from about 2 grams or less, such as about 1 protect the methenamine at different stages in the digestive gram to 500 milligrams (mg) or less including preferred system from the acidifier. It also reduces gastic pain result dosages of about 200 mg to about 500 mg, more preferably ing from the formation of formaldehyde with the conversion from about 300 mg to about 500 mg, still more preferably of the methenamine within the stomach. This permits greater from about 400 mg to about 500 mg and most preferably utility of the medicament for patient usage. from about 500 mg. US 2006/019888.6 A1 Sep. 7, 2006 0013 The methenamine compound of the present inven the gastric juices. A wide variety of other polymeric mate tion is coated with a pharmaceutical glaze to delay the rials are known to possess various solubility properties. breakdown of the methenamine in the stomach, and prefer Representative examples of enteric polymers include, with ably after leaving the stomach. The enteric coating is resis out limitation, polyvinyl acetate phthalate (PVAP), hydrox tant to disintegration at low pH levels and provides drug ypropylmethyl-cellulose acetate succinate (HPMCAS), cel release properties at higher pHs, such as for example becom lulose acetate phthalate (CAP) commercially available ing soluble at pH 5.5 and above, with maximum solubility under the tradename AquatenTM, methacrylic acid copoly rates at pHs greater than 6.5. Numerous enteric coated mer, hydroxy propyl methylcellulose Succinate, cellulose acetate Succinate, cellulose acetate hexahydrophthalate, and/or extended release pharmaceutical compositions and hydroxypropyl methylcellulose hexahydrophthalate, the methods of making these compositions are known in the hydroxypropyl methylcellulose phthalate (HPMCP), cellu art. By using the enteric coating, delivery of the meth lose propionate phthalate, cellulose acetate maleate, cellu enamine compound active pharmaceutical ingredient is lose acetate trimellitate (CAT), cellulose acetate butyrate, delivered within the body substantially beyond the stomach cellulose acetate propionate, methacrylic acid/methacrylate in the digestive tract, e.g., delivery in the lower GI tract, i.e., polymer (acid number 300 to 330 commercially sold under in the colon, or the upper intestines, i.e., the duodenum of the the tradename EUDRAGIT LTM, which is an anionic copoly Small intestine. The medicament includes a coating on the mer based on methacrylate and available as a powder (also methenamine compound to protect the methenamine com known as methacrylic acid copolymer, type A (USPNF), pound and release the methenamine compound at specific methacrylic acid-methyl methacrylate copolymer, ethyl locations within the digestive tract of the patient. Preferably methacrylate-methylmethacrylate-chlorotrimethylammo this includes an enteric coating for release of the meth nium ethyl methacrylate copolymer, poly(methacrylate enamine compound past the stomach area. The enteric coat ethylacrylate) (1:1) copolymer (MA-EA), poly(methacrylate may include one or more materials that remain intact during methylmethacrylate) (1:1) copolymer (MA-MMA),