Microemulsion Drug Delivery System: A Platform for Improving Dissolution Rate of Poorly Water Soluble Drug

Abstract

The aim of the present study was to design novel o/w microemulsion of Glimepiride and to study its dissolution behavior by raising its solubility.  Oil and surfactant were selected based on their drug solubilizing capacity and HLB value. Pseudoternary phase diagrams were developed at different ratios of Cremophor RH 40 and Transcutol P to know the microemulsion existing zone. Glimepiride loaded microemulsion using Labrafil M 1944 CS, Cremophor RH 40, Transcutol P as oil, surfactant and cosurfactant respectively, was prepared and characterized. Accelerated stability study of the developed microemulsion was carried out for 6 months. Drug solubilization capacity of the microemulsion system was determined. Solubility of Glimepiride by the O/W microemulsion was increased by 5785 times to that of water (0.019mg±0.002). In-vitro drug diffusion study revealed that after 10 hrs of diffusion, more than 18% of the drug was diffused from the microemulsion system, as compared to the commercially available tablets. Based on the results it could be concluded that microemulsion formulation could be used as a possible alternative to traditional oral formulations of Glimepiride to improve the dissolution rate and hence its bioavailability.