SELF-NANO EMULSIFYING DRUG DELIVERY SYSTEM (SNEDDS) FOR ORAL DELIVERY OF ATORVASTATIN- FORMULATION AND BIOAVAILABILITY STUDIES

The aim of the study was to develop a self-nano emulsifying drug delivery system (SNEDDS) for the  atorvastatin which belongs to BCS class II lipid lowering agent with poor water solubility and dissolution rate. The solubility of atorvastatin in individual micro emulsion components viz. oil and surfactants was determined. The surfactants were screened for emulsification ability. Based on the solubility determinations and emulsification properties oleic acid as oil; surfactants Brij 80 and Tween 80 were selected for further study. The solubility of atorvastatin in different ratios of selected oil and surfactants was determined. The composition of oil: Surfactant with maximum solubility for atorvastatin was used for SNEDDS formulation. Ternary phase diagrams were used to evaluate the micro emulsification existence area. The micro emulsions were evaluated for emulsion droplet size, self-emulsification time, phase separation, in vitro dissolution and stability. SNEDDS formulations found to be self-emulsified in 70 to 120 seconds without precipitation and their mean droplet sizes was 150 to 230 nm. Among the optimized formulations, formulation BF4 showed highest in vitro drug release. Formulation BF4 was composed of 20% oleic acid, 60% tween 80 and 20% brij 30 showed significant increases in the dissolution rate (99.65%) in 90 minutes and intestinal absorption (86.67%) than marketed product with 56.86% release and 45.34% oral absorption. Stability studies were conducted according to the Q1 ICH guidelines and found stable at different conditions