1. Guidance for Industry: ANDAs: Pharmaceutical Solid Polymorphism Chemistry, Manufacturing, and Controls Information;U.S. Department of Health and Human Services, Food and Drug Administration, Center for Drug Evaluation and Research (CDER):Rockville, MD, July 2007.
2. aICH Q8 Pharmaceutical Development,(R2);U.S. Department of Health and Human Services, Food and Drug Administration, Center for Drug Evaluation and Research (CDER):Rockville, MD, Aug 2009.
3. bICH Q9 Quality Risk Management;U.S. Department of Health and Human Services, Food and Drug Administration, Center for Drug Evaluation and Research (CDER):Rockville, MD, June 2006.
4. cICH Q10 Pharmaceutical Quality System;U.S. Department of Health and Human Services, Food and Drug Administration, Center for Drug Evaluation and Research (CDER):Rockville, MD, April 2009.
5. Form 2 is not discussed in this contribution as it is not relevant. Form 2 is a metastable form only obtained from tetrahydrofuran; it is not stable on storage and quickly converts to Form 1.