Capturing The Significance of X-Ray Crystallography in Pharmaceutical Field: The Application to Characterize New Salt, Co-Crystal and Co-Amorphous Etsuo Yonemochi Department of Physical Chemistry, School of Pharmacy and Pharmaceutical Sciences, This document was presented at PPXRD - Pharmaceutical Powder X-ray Diffraction Symposium Sponsored by The International Centre for Diffraction Data This presentation is provided by the International Centre for Diffraction Data in cooperation with the authors and presenters of the PPXRD symposia for the express purpose of educating the scientific community. All copyrights for the presentation are retained by the original authors. The ICDD has received permission from the authors to post this material on our website and make the material available for viewing. Usage is restricted for the purposes of education and scientific research. PPXRD Website – www.icdd.com/ppxrd ICDD Website - www.icdd.com Acyclovir • Guanosine analogue antiviral drugs. • The treatment of herpes simplex virus infections. 2 Outline Screening and Characterization Screenig methods and used additives Selected cocrystals (PXRD、TG/DTA、DSC） Application for oral dosage form Intrinsic dissolution of selected cocrystal Crystal structure of selected cocrystal Mechanism for solubility enhansment Application for transdermal dosage form Transdermal adsorption propertiy of selected complex Solubility of amorphous comples Improvement of transdermal properties 2/3 Hydrate Commercially available Recrystalized from ethanol solution P21/n a 25.459(1)Å b 11.282(1)Å c 10.768(1)Å β 95.16(1)° Volume Column structure 3080.342Å3 Stacking purine moiety Z 12 R-factor 5.3％ Dihydrate From ammonium solution P-1 a 6.8386(7)Å b 11.3679(14)Å c 14.942(2)Å α 82.845(4)° β 82.419(3)° γ 89.326(3)° Channel structure Volume 1142.5(2)Å3 Stacking purine moiety Z 4 R-factor 7.71％ Anhydrate2 Dehydration of hydrates P21/c a 10.9399(6)Å b 11.1837(6)Å c 8.1164(4)Å Stacking purine β 108.6277(34)° Volume moiety 941.009Å3 Z 4 Anhydrate2 Crystallization by Vapor-Diffusion. Procedure. (DMF+Acetonitrile) P 212121 a 4.5387(10)Å b 15.0308(3)Å c 28.3320(6)Å Volume 1932.82Å3 Z 8 R-factor 9.88％ Different stacking mode Dissolution properties for acyclovir polymorphs Intrinsic dissolution rate 1.5 ・area for disson：0.2 cm2） Similar dissolutin rate ・pH 6.8 Phosphate buffer 1.2 ・37℃ . ・50 rpm anhydrate1 c n o 2/3hydrate ) 0.9 C L r i m / v g o l μ c ( 0.6 Anhydrate2 y c 2hydrate A 0.3 polymorphs 0 0 1 2 3 4 5 Time (min) Transformation of anhydrate to hydrate was quick. Anhydrates were useless Hydration mechanisum？ Hydration properties for acyclovir anhydrate2 Reversible Anhydrate 2 Dihydrate 2/3 hydrate Hydration properties for acyclovir anhydrate1 25℃ RH95％ 1week Anhydrate 1 2/3 hydrate Dihydrate Irreversible Anhydrate 2 Comparison between transition behavior and stacking mode antiparallel parallel parallel 2/3 Hydrate Anhyd. 1 Anhyd. 2 Di hydrate antiparallel antiparallel Similarity of stacking The phase transition mechanism is complicated. X-ray DSC Anhydrate Form 2 Anhydrate Form 4 Anhydrate Form 2 Anhydrate Form 4 Anhydrate Form 3 2/3 hydrate 12 XRPD patterns of acyclovir using HT capillary sample holder 2.5e+004 2.0e+004 Intensity(cps) 1.5e+004 Anhydrate Form 2 (RT) 1.0e+004 Anhydrate Form 4 (210℃) 5.0e+003 2/3 hydrate (RT) 20 40 60 80 2-theta (deg) 13 Comparison from the view of stacking structure antiparallel 2/3 hydrate Anhydrate Form 4 Anhydrate Form 2 antiparallel parallel parallel 14 Anhydrate Form 1 Phase Transition of Acyclovir polymorphs Anhydrate 3 120oC o RH95% 170 C 2/3 hydrate Anhydrate 1 at 25oC Anhydrate 4 RH0% RH20% o at 25oC 170 C at 25oC Dihydrate Anhydrate 2 Conclusion • There are two packing manners for purine moiety. Anhydrate 1, anhydrate 2, 2/3 hydrate and ACV dihydrate were packed in parallel, antiparallel, mixture of parallel—anti-parallel and parallel manners, respectively. • Based on the packing manner of ACV, it can be seen why the phase transformation occurs with readily or with difficulty. 16 Outline Characterization Screenig methods and used additives Selected cocrystals (PXRD、TG/DTA、DSC） Application for oral dosage form Intrinsic dissolution of selected cocrystal Crystal structure of selected cocrystal Mechanism for solubility enhansment Application for transdermal dosage form Transdermal adsorption propertiy of selected complex Solubility of amorphous comples Improvement of transdermal properties dissolution properties O N HN N Sprangly soluble in water O H2N N OH Dissolution rate and solubility for water Activity related to the solubility in base Oral dosage form Transdermal Bioavailability：low Transdermal Absorption ：low D. Patel, et al. Drug. Dev. Ind. Pharm. 33:1318 (2007). D. J. Freeman, et al. Antimicrob. Agents Chemother. 29:730 (1986). Improvement of solubility Improvement of the physicoshemical properties methods polymorphs Salt formation Package gringing Solvate Cocrystal Solid dispersion amorphous O N HN N O H2N N OH Applicaton for oral dosage form Cocrystal→Improvement of dissolution properties Application for transdermal dosage form Amorphization→Increase the solubility in base→ Increase the absorption Cocrystal・・・ polymorph hydrate/solvate pure API salt of API of pure API of API ・単位格子中に固体分子 種以上含有 Multicomponent crystal2 Neutral API ・水素結合等で分子が結合 ・多Hydrogen成分結晶 bonding, Neutral Water/solvent Charged API 単Multicomponent一分子から構成される crystal結晶では得られない Counter ion pharmaceutical に期待 Hydrogen物性・機 bonding,能の発 Neutral現 Cocrystal former cocrystals ACV has many functional groups, O N Capable to make hydrogen bonding HN N O Cocrystal formation H2N N OH Generally recognized as safe compound :Hydrogen bond donor or acceptor sites Amorphization of Acyclovir Melt O Decomposion N HN Solvent evaporation N O Unstable H2N N OH Spray dry Addition of polymer Freeze dry High Cost Decrease the diffusion rate in base Comventional methods isn’t suitable for the amorphization Preparation of Amorphous complex with additives Outline Characterization Screenig methods and used additives Selected cocrystals (PXRD、TG/DTA、DSC） Application for oral dosage form Intrinsic dissolution of selected cocrystal Crystal structure of selected cocrystal Mechanism for solubility enhansment Application for transdermal dosage form Transdermal adsorption propertiy of selected complex Solubility of amorphous comples Improvement of transdermal properties Screening methods Acyclovir anhydrous Excipient Screening by form 2 Solvent, Grinding Solvent method Grinding method Solvent Liquid assisted grinding Neat grinding (Solvent drop method) Hot suspension of drug and cocrystal former Liquid assisted grindig Filtration Solvent Ground manually at room temperature Ground manually at room temperature Saturated solution of 14additives drug and cocrystal former Slow evaporation 9 solvent or Cooling Crystallized complex or Amorphous complex Evaluated by PXRD, Themal Analysis PXRD, TG/DTA Generally recognized as safe compounds used O OH OH O O OH O O O HO OH O OH HO H N OH HO OH O 2 OH O OH OH NH2 Citric acid Tartaric acid Malic acid Glycine Alanine O NH O O HO OH H N N OH 2 H OH O NH2 NH2 Stearic acid Aspartic acid Arginine O OH O O O Palmitic acid NH NH2 H N NH S 2 2 O O N O OH Urea Nicotinamide Saccharin Docosanoic acid O OH Lauric acid Existence of the records as Oral or Trandermal application PXRD patterns of samples Anhydrate1 5 10 15 20 25 Anhydrate2 5 10 15 20 25 2/3 hydrate 5 10 15 20 25 2hydrate Relative intensityRelative 5 10 15 20 25 Citric acid 5 10 15 20 25 Cocrystal 5 10 15 Halo2 0pattern 25 Amorphous complex 5 10 15 20 25 2θ/ degree TG/DTA curve of samples 0 0 169℃ Citric acid Anydrate1 Weight loss DTA curve 100 100 0 exo.→ 0 25 80 135 190 245 300 T 25 80 135 190 245 300 Δ Weight loss (%) loss Weight Anhydrate2 157℃ Cocrystal 100 100 → exo.→ 0 25 80 135 190 245 300 T 25 80 135 190 245 300 Δ Weight loss (%) loss Weight 2/3hydrate 100 0 25 80 135 190 245 300 Clear difference in curves 2hydrate No possibility of the 250℃ formation of solvate 100 25 80 135 190 245 300 DSCcurves of amorphous complex Tg ) mW 40 50 60 70 80 90 Tg Heat flow( ↑ Endo 68℃ -40 -20 0 20 40 60 80 100 Temperature (ºC) Glass transition temperature Tg was higher than the room temperature. Confirmation of the physical stability of amorphous complex Outline Characterization Screenig methods and used additives Selected cocrystals (PXRD、TG/DTA、DSC） Application for oral dosage form Intrinsic dissolution of selected cocrystal Crystal structure of selected cocrystal Mechanism for solubility enhansment Application for transdermal dosage form Transdermal adsorption propertiy of selected complex Solubility of amorphous comples Improvement of transdermal properties Crystal structure of Acyclovir‐Citric acid Cocrystal Single crystals weren’t obtained Crystal structure analysis using powder diffraction data obtained by synchrotron radiation Stoichiometry of Acyclovir : Citric acid was 1:1 Comparison of stacking structure of Acyclovir and its cocrystal Anhydrare2 Acv-Citric acid Cocrystal Cocrystal Stacking structure of Purine frame Citric acid Un-stabilize the stacking structure by intercalation of citric acid Enhancement of the solubility Distance in the purine frame in the crystals 14 ) Å 12 10 8 No difference 6 4 stacking distance stacking( distance π π - 2 π 0 Anhyd.1 Anhyd.2 2/3hydrate Dihydrate Cocrystal Change in the crystal strucuture by cocrystal Improvement of dissolution property Saturated Solubility of Cocrystal in various solvents 10.00 Enhancement of solubilty : Distilled water 8.00 : Phosphate buffer pH 6.8 : Ethanol 6.00 4.00 2.00 Saturated solubility (mg/mL) 0.00 1 2 3 4 5 6 7 8 9 Acyclovir anhydrous form 2 ACV-TA-PM ACV-TA cocrystal Physical mixture showed the similar solubility compare to the Cocrystal ACV and Citric acid was interacted, even in the solution.