Applicability Of A Natural Swelling Matrix Stemed From Boat-fruited Sterculia Seed As Propellant Of Osmotic Pump Tablets

Osmotic pump preparations are having been widely applied by reason of thezero-order release in a constant speed. The osmotically active substance in the core hasobtained increasely development, including not merely initial sodium chloride, but alsopolymers such as polyethylene oxide. We thought that searching appropriateosmotically active substances with water-swelling properties from nature couldprovide some basis for novel and excellent materials. Boat-fruited sterculia seed wasone of the third batch resources suitable for both food and medicine published byMinistry of Health of China. The water-swelling characteristics of boat-fruitedsterculia seed were used in this study. The middle lamella of testa, that was swellingmatrix of boat-fruited sterculia seed, was extracted first. The physical pharmaceuticalproperties of SMS were investigated. Our results indicated that SMS conformed to therequest for direct compression basically, exhibited relatively high swelling ability.Compared with that of polythylene oxide (WSR-N10and WSR-303), the area of thedisintegrated matrix tablet was20.1times as that at initial after swelling for600s.SMS swelled rapidly and was fully swelled (0.5%) in aqueous solution with relativelow viscosity (3.66±0.03) mPa·s at25℃. Preliminary results showed that SMS wasmainly composed of76.30%rhamnose,15.08%arabinose,2.83%xylose and5.79%galactose.In this study, Ribavirin and glipizide were used as water-soluble and water-insolublemodel drugs respectively. The monolayer osmotic pump tablets of ribavirin and thebilayer osmotic pump tablets of glipizide using SMS as propellant were prepared andeffects of prescription compositions on drug release were investigated. Osmotic pumptablets of both ribavirin and glipizide exhibited typical drug release features of osmoticpumps. In conclusion, SMS is a potential propellant in the application of osmotic pumptablets.