FORMULATION AND EVALUATION OF NOVEL MICROEMULSIONS OF ATORVASTATIN CALCIUM TRIHYDRATE

The objective of the present study was to develop a novel microemulsion drug delivery system of a poorly water soluble drug Atorvastatin calcium trihydrate. The oral delivery of such drugs is frequently associated with implications of low bio availability, high intra and inters subject variability and lack of dose proportionality. Phase solubility studies were conducted for the maximum solubility of Atorvastatin. Highest solubility was found in Tween80, Transcutol (surfactants), PEG400, Cremophor RH40 (cosurfactant) and Isopropyl myristate, Sunflower oil (oil). Ternary phase diagrams were constructed to evaluate microemulsion regions. FTIR analysis was done for investigating the drug-excipient interactions. The mean globule size of both microemulsion was observed to be below 200nm for the optimized formulations and the zeta potential was negative. The dissolution of emulsion formulations was compared to commercial tablets, the results indicated that the rate of dissolution of developing formulations containing Atorvastatin was increased compared with that of commercial tablets. SEM studies were done for the shape and morphology of the globules. Thus, micoemulsions can be regarded as novel and commercially feasible alternative to the current Atorvastatin formulations.