Abstract
The mechanism of release of clofibrate from microcapsules prepared in a gelatin-sodium sulfate system has been investigated. A theoretical model was developed to explain the release pattern of the drug from the microcapsules. It was shown that the release of the drug followed four stages giving individual zero-order profiles. The overall release from the thin-walled microcapsules showed greater deviation from the zero-order kinetics but followed the square-root of the time plots. Microcapsules having thicker walla approximated overall zero-order release but deviated from the square-root of time plots. The effect of hardening on the release profiles and possible explanations for the differences observed in the release of clofibrate from the thin-walled and thick-walled microcapsules are discussed.