Studies on Release of Helicid Bioadhesive Sustain-Release Tablet and Determination of Adhesive Force in Vitro

OBJECTIVE To study the drug release mechanism of helicid(HD) bioadhesive sustained-release tablet and to determine the adhesive force in vitro.METHODS Using rotating basket method,the accumulative drug release was determined with water as releasing mediums at the speed of 100 r·min~(-1);several mathematic models were used to simulate the release curve.The biggest absolute error,the biggest relative error and AIC were used as comprehensive indices to select the best optimum model.A building apparatus was used to determine the adhesive force at rat stomach and small intestine in vitro.RESULTS The Higuchi and Ritger-Peppas models were chosen as the optimum model for HD bioadhesive sustained-release tablet. The adhesive forces were 6.1 and 13.2 kPa in rat stomach and small intestine respectively.CONCLUSION The releasing parameter of n is 0.619 9.The releasing action is the result of both diffusion and erosion mechanism.The HD bioadhesive sustained-release tablet is adhesive in stomach and small intestine and the adhesive force is stronger at small intestine than that in stomach.