FORMULATION AND RELEASE KINETICS OF SUSTAINED-RELEASE PEPPERMINT OIL GRANULES FOR TREATMENT OF THE IRRITABLE-BOWEL-SYNDROME

In this study, peppermint oil was formulated in the form of sustained release granules composed of stearic acid, hydrophobic silica and microcrystalline cellulose (MCC). The release rate was measured as a function of MCC and peppermint oil concentration in the granules. The rate of release was markedly increased as the concentration of either MCC or peppermint oil increased. The release data were evaluated kinetically by zero and first orders, Higuchi, Langenbucher and modified Langenbucher release kinetics. The highest correlation coefficient and the best linear relation were obtained with the modified Langenbucher equation. This was followed by Higuchi and first order release kinetics.