FORMULATION AND DEVELOPMENT OF ANTI-HYPERTENSIVE OSMATIC TABLETS

The main objective of this dissertation is to formulate elementary osmotic pump for verapamil that can provide a desired therapeutic releasing the drug in the zero-order for better patient compliance. Verapamil is calcium channel blocker was selected as a model drug to be formulated into osmotic drug delivery system. Elementary osmotic pump core tablets for verapamil non- aqueous wet granulation were prepared by using osmogen like mannitol. The coated tablets were drilled by using mechanical drill by mechanical means using softclix - modified sharp needle. The drilled orifice sizes on coated tablets were evaluated by using scanning ocular micrometer. By performing compatability studies with FTIR and no interaction is found hence the granules were prepared and evaluated. Granules evaluated for precompression parameters such as angleofrepose, bulkdensiy, tapped density, compressibility, hauner ratio and tablets post compression parameters such as drug content, weight variation, friability, thickness, hardness, in vitro dissolution. The drug release studies were analyzed for kinetics model to determine its order and mechanism of drug release. F5 formulation shows highest percentage of drug release (24hours) hence it was optimized formulation. The n values for all the formulations ranged from 0.6 to 1.2 indicating different release patterns viz. Fickian (n = 0.5), case II non-Fickian (anomalous) release (0.5? n ? 0.89), super case II type of release (?0.89). Based on the diffusion control studies, it was observed that the optimized formulation F5 2%coating it follows zero order release (0.9), endured super case II release mechanism (n= 1.2), during the dissolution study, which indicated that polymer relaxation had a significant role in the drug release mechanism. In the non-Fickian (anomalous) case II release, the rate of drug release is due to the combined effect of drug diffusion and polymer relaxation. Super Case II release generally refers to the polymer relaxation. Nature of release of the drug from the osmatic tablets was inferred based on the correlation coefficients obtained from the plots of the kinetic models.