Abstract

Diltiazem is frequently recommended to be administered as a controlled release formulation. The current study aims at development and optimization of controlled release microcapsules of diltiazem hydrochloride. The microcapsules were formulated as per factorial design taking rate controlling coat polymer (ethylcellulose) and emulgent (Span 80) as the factors at three level each. The formulations were tested for drug release, entrapment efficiency, size and surface topography using Scanning Electron Microscopy. A polynomial equation for each response variable was constructed. The resultant data were critically analyzed to locate the composition of optimum formulations, the corresponding microcapsules were formulated and thoroughly evaluated. The microcapsules were topographically regular with over 90% encapsulation efficiency. The release profile using optimized formulation was found to be quite regulated for controlled release purposes (t80% = 9.5 h) with little dose dumping (release upto 16 h = 99%). All the predicted values of response variables demonstrated close agreement with the experimental data.