Formulation and Evaluation of Nanocrystals of a Lipid Lowering Agent

Atorvastatin calcium, the lipid lowering agent, is taken as a model drug characterized by poor water solubility and bioavailability. In this study an attempt was made for preparation of nanocrystals using high pressure homogenization. A number of stabilizers were included as well as polymers at different concentrations, and the formulations were homogenized for ten cycles at a pressure of 1000 bars. The obtained nanocrystals were evaluated by determining their size, zeta potential, saturated solubility and dissolution rate. Results revealed that Formulation 3, containing (10: 1) drug to sodium lauryl sulphate ratio, possessed the highest saturated solubility and dissolution rate, and hence was analyzed by X-ray diffraction analysis, differential scanning calorimetry, Fourrier transform infrared spectroscopy and scanning electron microscopy. An in-vivo study was carried out on the successful formulation in comparison to drug powder using rats as experimental animals. A significant increase in the area under the concentration-time curve Cpmax and MRT for nanocrystals was observed in comparison to the untreated atorvastatin calcium.