ENHANCING THE BIOAVAILABILITY OF SIMVASTATIN USING MICROEMULSION DRUG DELIVERY SYSTEM

Abstract

The objective of the present study was to develop a novel Microemulsion drug delivery system (ME) to enhance the solubility, dissolution rate and ultimately the oral bioavailability of a poorly water soluble drug, Simvastatin. Phase solubility studies were conducted using various oils and non-ionic surfactants for the maximum solubility of Simvastatin. Ternary phase diagrams were constructed to evaluate the microemulsion regions and were also for the optimum concentrations of oil (Oleic acid) and surfactant (Cremophore RH 40), Co-Surfactant (Transcutol p) and water in the formulation. The globule size analysis, and zeta potential of all the developed formulations were studied using Zeta Sizer (Horiba Instruments, Japan). In vitro release studies are conducted using USP Type II dissolution test apparatus and in-vitro intestinal permeation studies are conducted using Rat duodenum. The formulation of microemulsion was compared with marketed tablet. The Results of the studies indicated that, the dissolution rate and intestinal permeation of the developed ME formulation containing simvastatin was 2.5 to 3 folds increased compared with that of marketed tablet. The mean globule size (n=3) was observed to be (< 100nm) for the optimized formulation and the zeta potential was negative which may not interfere in the absorption of the formulation. Therefore the developed microemulsion formulation improved the Solubility and in-vitro drug release of simvastatin when compares with commercial tablet formulation.