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Updated: Aug 15, 2026

Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by π-π Stacking Interactions
Published on: October 10, 2016
Physical structure characterization of theophylline in some acidic film-forming polymers
N Sarisuta1, M Kumpugdee, P Lawanprasert
1Department of Manufacturing Pharmacy, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand.
Abstract:
The physical structure and drug-polymer interactions of theophylline in Eudragit L100, shellac, polyvinyl acetate phthalate (PVAP), cellulose acetate phthalate (CAP), hydroxypropylmethylcellulose acetate phthalate (HPMCP), and hydroxypropylmethylcellulose (HPMC) were studied. The drug-polymer films were prepared by casting and were characterized using powder X-ray diffractometry (PXRD), nuclear magnetic resonance (NMR) spectroscopy, and thin-layer chromatography (TLC). Theophylline was found to recrystallize in the modification II form in all kinds of polymers, which was the same as that recrystallized solely from the solvent system and the original powder. The PXRD and NMR results indicated a superficial drug-polymer interaction between theophylline and Eudragit L100, while there was no evidence of interaction for the others. No drug decomposition was observed by TLC for all drug-polymer mixtures.
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