FORMULATION AND CHARACTERIZATION OF ATORVASTATIN SOLID DISPERSIONS FOR IMPROVED BIOAVAILABILITY

Manju Singh, Richa Sharma and Vijay Kumar*

Solid dispersions (SDs) of atorvastatin (ATS) using PEO-PPO block copolymer resulted in the formation of an amorphous product with enhanced dissolution and bioavailability. Solubility enhancement was observed in the presence of selected carriers and it increased with the increase in concentration of carriers. The carrier and the active ingredient are dissolved in a suitable organic solvent is evaporated to an elevated temperature or under vaccum. As the solvent is being removed, super saturation occurs followed by simultaneous precipitation of the constituents resulting in a solid residue. The solvent-based process uses organic solvent to dissolve and intimately disperse the drug and carrier molecule The accumulative solubility of atorvastatin (ATS) from PEO- PPO block copolymer (Poloxamer 188) was found to be superior from glyceryl monostearate and PEG 4000 carriers due to increased content which played major role in solubility enhancement thus improving dissolution rate of SD2 batch with maximum drug release (98.08 %) in 120 minutes. The optimized SDs were characterized by saturation solubility study, drug content, in vitro dissolution, fourier transform infra-red spectroscopy, scanning electron microscopy, and x-ray diffraction. Capsules containing optimized SDs were prepared and compared with marketed brand (LIPITOR®). Finally it can be concluded that optimized SDs of ATS ameliorate the solubility and dissolution of drug. Since the batch SD2 elicited superior results, it can be proposed as good candidate for systemic product development.