FORMULATION AND CHARACTERIZATION OF ATORVASTATIN PHARMACOSOMES AS AN ALTERNATIVE APPROACH TO CONVENTIONAL VESICULAR SYSTEM

Abstract

The vesicular systems are the concentric lipid bi-layer assemblies that are formed when certain amphiphilic building blocks are confronted with water. This system extends the therapeutic index by encapsulating the drug molecules inside the vesicular structure. It prolongs the presence of drug molecules in systemic circulation and reduces the toxicity which in turn results in the modification of pharmacokinetics and bio distribution of drugs. Pharmacosomes serve as an alternative to conventional vesicles, have unique advantages over liposome, noisome, transferosomes etc. and are defined as colloidal dispersions of drugs covalently bound to lipids and may exist as ultrafine vesicular, micellar or hexagonal aggregates. The objective of the present study was to prepare and evaluate atorvastatin calcium pharmacosomes using two different ratios (1:1 and 1:2) of drug and phosphatidylcholine in the presence of dichloromethane by solvent evaporation technique. The results of physicochemical study showed higher solubility of almost tenfold increase in solubility of pharmacosomes formulation as compared to pure drug. The dissolution rate of phospholipid complex is also improved to 98% from 93%. Hence phospholipid complex of drug can be used as a potential tool of improving dissolution rate and bioavailability. The release data was fit into different kinetic models and it has been found to follow Higuchi model with a Fickian release mechanism in all the formulations.