Abstract

MONTMORILLONITE USED AS AN EXTENDED RELEASE DELIVERY VEHICLE AND INCREASE BIOAVAILABILITY FOR METOPROLOL TARTRATE: AN ANTIHYPERTENSIVE DRUG

Arun Kant and Monika Datta*

Abstract

The aim of the present work Montmorillonite (Mt) based drug delivery system has been explored for the extended release of an antihypertensive drug Metoprolol tartrate (MPT). Employing the batch extraction method, interaction of MPT with Mt was investigated as a function of pH of the aqueous drug solution, contact time and initial drug concentration in the aqueous solution. The prepared Mt-MPT complex has been characterized using various appropriate analytical techniques for explaining the interaction of MPT with Mt including Xray diffraction (XRD), Fourier Transform Infrared Spectroscopic Studies (FT-IR), Thermogravimetric analysis (TGA), Transmission Electron Microscopy (TEM) and Scanning Electron microscopic (SEM) imaging with EDX analysis. The results indicate that adsorption kinetic could be best described by the pseudo-second-order kinetic model and the isotherm model was best described by Langmuir adsorption isotherm. In-vitro drug release behaviour perform in simulated gastric and simulated intestinal fluids, it has been observed that Mt-MPT complex provide better extended release of MPT as compared to the pure MPT and the commercially available tablets (Metolar and Betaloc). Kinetic models (first order model and Korsmeyer- Peppas model) were also applied to show the kinetics of drug release behaviour. From the invitro drug release data possible bioavailability of MPT in case of for Mt-MPT complex have been calculated and it has been observed that, compared to the pure MPT and the commercially available tablets performance of the prepared Mt-MPT complex has been found superior in terms of probable percentage bioavailability and also in terms of availability of the drug in the simulated gastric and simulated intestinal fluids for a longer period of time.

Keywords: Adsorption, intercalation, extended release, bioavailability and kinetics.