The Application of Dextran Derivatives to Sustaind Release Tablet of Theophylline.

An application to controlled drug delivery was investigated for dextran derivatives, a natural α-1, 6 glucan, in reference to the polyelectrolyte complex (PEC) formation between [2-(diethylamino) ethyl] dextran hydrochloride (EA) and sodium carboxymethyldextran (CMD). Compressed tablets containing theophylline (TH) as a model drug and dextran derivatives as fillers were examined.PEC formation was examined by turbidity measurement and Fourier-transform infrared spectroscopy. A rapid dissolution of TH was observed when the tablet was prepared with lactose excipient. A controlled release of TH was observed in 1st and 2nd disintegration test fluid when the tablet was prepared with either physical mixture of EA and CMD or PEC consisting of EA and CMD as excipients. By applying the release date to Higuchi's equation, mode of drug release appeared to be not diffusion-controlled.