IN VITRO SUSTAINED DELIVERY OF ATENOLOL, AN ANTIHYPERTENSIVE DRUG USING NATURALLY OCCURRING CLAY MINERAL MONTMORILLONITE AS A CARRIER

Abstract

In the present study, a naturally occurring clay mineral, Montmorillonite, (Mt) has been explored as a carrier for an antihypertensive drug, Atenolol. The effect of pH, time and initial drug concentration on drug loading capacity of Mt has been evaluated. The adsorption isotherm was fitted by the Langmuir model and follows the pseudo-second-order kinetics. The synthesized Mt-Atenolol complexes were characterized by XRD, FTIR, TGA, DSC etc.  XRD data indicates the intercalation of Atenolol within the Mt layers. The release profile of the Atenolol from Mt-Atenolol complexes is compared with the pure Atenolol, in simulated gastric and intestinal fluids. The release behaviour of Atenolol from MT-Atenolol Complexes appears to be in sustained manner over a period of 24 hours and reaches upto 40% and 27% in simulated gastric and intestinal fluids respectively. As compared to pure Atenolol, extended gastric retention time was observed for Atenolol-Mt complexes  indicative of the increased extent of absorption and bioavailability of the drug.  Various kinetic models were used to elucidate the drug release mechanism, the best fitting was found for Higuchi and Korsmeyer-Peppas model. The synthesized Atenolol-Mt complexes have the potential for developing in to a  sustained release formulation for oral drug delivery. Thus, proposing a promising formulation for oral sustained drug delivery of Atenolol.