Evaluation of Ocimum basilicum L. seed mucilage as rate controlling matrix for sustained release of propranolol HCl

Polysaccharide mucilage derived from the seeds of Ocimum basilicum L. (family Lamiaceae) was investigated for use in matrix formulations containing propranolol hydrochloride. Basil mucilage was extracted and several tablets were formulated. The effect of mucilage on drug release rate was evaluated in comparison with tablets containing two kinds of hydroxypropyl methylcellulose (HPMC K4M and HPMC K100M) as standard polymer. The release data were fitted to several models for kinetic evaluation. The results showed that hardness decreased and friability of tablets increased as the concentration of mucilage increased. The rate of release of propranolol HCl from O. basilicm mucilage matrices was mainly controlled by the drug:mucilage ratio. Drug release was slower from the tablets containing HPMC K4M and HPMC K100M compared to the mucilage containing matrices than the drug release from matrices containing O. basilicum seed mucilage in similar ratios (P < 0.001). Formulations containing O. basilicm mucilage were found to exhibit suitable release pattern. The results of kinetic analysis showed that in tablets containing O. basilicm mucilage the highest correlation coefficient was achieved with the zero order model. The swelling and erosion studies revealed that, as the proportion of mucilage in tablets was increased, there was a corresponding increase in percent swelling and a decrease in percent erosion of tablets.