To Study the effect of Cross linking of Sodium Alginate on the Rate of Drug Release

Verapamil hydrochloride (VH) is a calcium channel blocking agent used in the treatment of hypertension, cardiac arrhythmia and angina pectoris. The short half life and high frequency of administration of VH makes it a suitable candidate for designing sustained drug delivery system. The aim of the present investigation was to develop a sustained release matrix tablet of verapamil hydrochloride (VH) using sodium alginate and cross linked sodium alginate and to evaluate the drug release kinetics. In order to achieve the required sustained release profile, the tablets were prepared by a wet granulation method. The formulated tablets were characterized for pre-compression and post-compression parameters and they were in the acceptable limits. The drug release data obtained after an in vitro dissolution study was fitted to various release kinetic models in order to evaluate the release mechanism and kinetics. The criterion for selecting the best fit model was linearity (coefficient of correlation). Drug release mechanism was found to follow a complex mixture of diffusion, swelling and erosion. The dosage form holds the potential to control the release rate of drug and extend the duration of action of a drug.