Eudragit-S, Eudragit-L and cellulose acetate phthalate coated polysaccharide tablets for colonic targeted delivery of azathioprine

The present work deals with the formulation and evaluation of polymer-coated polysaccharide tablets of azathioprine prepared by direct compression method using different ratios of avicel (MCC), inulin and triacetin. The tablets formulations containing 25 mg of azathioprine were prepared and evaluated for thickness, hardness, friability, weight variation, content uniformity and in vitro dissolution test. Hardness and percentage friability were in the range of 7.23–7.43 kg/cm2 and 0.21–0.41%, respectively, and showed 99–100% uniformity in drug content. The coated tablets exploiting different polymer combinations were evaluated for drug release under different pH conditions. The formulation containing Eudragit-S®, Eudragit-L® and cellulose acetate phthalate (ES®, EL® and CAP) (1:1:1) displayed desired release pattern with only 9.75% drug release in first 5 h (lag phase) and satisfactory release in lowered pH conditions. Drug release increased with the plasticizer (triacetin) concentration. Increase in the co...