In vitro In vivo comparison of two pH sensitive Eudragit polymers for colon specific drug delivery

The aim of this study was to develop the polymer coated diclofenac tablet containing superdisintegrant for colonic drug delivery and compare the in vivo performance of two polymers for site specificity. Eudragit FS 3D and Eudragit S100 were used as pH sensitive polymers. Tablets were prepared to give fast release at specific site with the help of sodium starch glycolate as superdisintegrant. Tablets were coated separately with Eudragit FS 30D and Eudragit S100 in various thicknesses and evaluated for in vitro drug release using changing pH method. X ray imaging was used to monitor the placebo tablets throughout the gastrointestinal system. In vitro release studies reveals that Eudragit FS30D coated tablet with 10%w/w coating level start release of drug at pH 6.8 after suitable lag time in the same pH which corresponds to colonic arrival time, as compare to Eudragit S100 coated tablet which release only at higher pH , approximating the transverse colon. In vivo study shows that Tablet coated with Eudragit FS30D with 10%w/w coating level and Eudragit S100 with 10% coating level disintegrated in cecum region. Thus Eudragit FS30D coated tablet may be a promising system for the treatment of colonic disease where pH may decrease and drug also start to release at the same pH after suitable lag time as well as release of drug at the beginning of colon so drug will be available in solution or disperse form for local and systemic effect throughout the colon.