OPTIMIZATION OF GASTROADHESIVE DELIVERY SYSTEM FOR NARROW ABSORPTION WINDOW DRUG USING NATURAL POLYMERS

A system comprising mechanisms of gastric retention by gastroadhesion has been investigated employing combination of hibiscus esculentus mucilage and xanthan gum for diltiazem hydrochloride. Various formulations of diltiazem hydrochloride were prepared by wet granulation technique using Box-Behnken approach and were tested for compatibility, swelling behaviour, in vitro drug release, mucoadhesive strength and accelerated stability. The percent cumulative drug release at 8th hr (Y1), time to release 80 % of drug (Y2), mucoadhesive strength (Y3) and mucoadhesive time (Y4) were used as the formulation responses in order to optimize the formulation. The accelerated stability studies revealed that the tablets retained their characteristics even after stressed storage conditions. The DLT mucoadhesive matrices were 49.99 mg hibiscus esculentus mucilage, 44.97 mg xanthan gum and 4.48 ton compression load fulfilled the optimal criteria of best sustained release rate and bioadhesive characteristics with t80% of 7.6 h, Q8h of 89.83 % and bioadhesive strength of 22.14 g.