Crystallinity of Omeprazole in Various Film Polymers

Abstract

The crystallinity of omeprazole in six film-forming polymers, Eudragit L100, shellac, polyvinyl acetate phthalate, cellulose acetate phthalate, hydroxypropyl methylcellulose acetate phthalate and hydroxypropyl methylcellulose (HPMC) was determined. Polymer films containing omeprazole were prepared by casting and characterized using powder X-ray diffractometry, Fourier transform infrared spectroscopy, and differential scanning calorimetry. Omeprazole powder recrystallized from all solvents studied were similar to the original powder. The drug existed as the amorphous form in the five acid polymers whereas its crystalline form appeared in nonionic polymer HPMC. No evidence of a drug-polymer interaction was found. Omeprazole exists in amorphous form in polymers most commonly used in enteric filmcoated formulations.