Abstract

DEVELOPMENT OF GASTRO RETENTIVE MATRIX TABLETS OF ENALAPRIL MALEATE: IN VITRO EVALUATION ON FACTORS INFLUENCING DISSOLUTION RATES

Sreenivasa Reddy N.*, Mahendra Kumar C. B. and Ramesh A.

ABSTRACT

The objective of the study was to develop Gastro retentive matrix tablets of Enalapril maleate, an antihypertensive drug. The matrix tablets of antihypertensive drug Enalapril maleate were prepared as per the optimized formulation developed in the earlier studies. The formulation with Hydrophilic and hydrophobic low density polymers like HPMC M4K and natural gums like Karaya gum, Pullulan gum were used alongside with other excipients. The pre-compression parameters, compatibility of drug with various excipient was studied by Fourier Transfer Infra Red (FTIR) and Differential Scanning Colorimeter(DSC) analysis. The tablets were directly compressed and evaluated for compliance with pharmacopeia limits. The formulation of FE investigated for post compression parameters like hardness, thickness, friability, buoyancy, in vitro dissolution and stability studies. The morphology of FE formulation soaked with simulated gastric fluid at different time intervals was studied by Scanning Electron Microscopic(SEM) to study the factors influencing the dissolution rates. The Drug release is found to be retarded for prolonged time due to swelling of tablets and diffusion of drug through pores. The results of floating lag time (FLT), total floating lag time (TFT), and in vitro dissolution studies indicated that formulation FE shown similar desired values as predicted for optimized formulae developed. The curve fitting kinetics was studied for in vitro drug release of FE formulation, and was found to be non-fickian, and by diffusion. The formulation FE holds good for developing Gastro retentive matrix tablets for antihypertensive drugs.

Keywords: Enalapril maleate, Karaya gum, Pullulan gum, HPMC M 4K, FLT, TFT.