Formulation and Evaluation of Immediate Release Pravastatin Sodium Tablets

The objective of this research was to formulate fast dissolving tablets of Pravastatin sodium that disintegrate in the oral cavity upon contact with saliva and there by improve therapeutic efficacy. Pravastatin sodium is used for the treatment of myocardial infarction. Fast dissolving tablets of pravastatin sodium were prepared by direct compression method using three different superdisintegrants-Sodium starch glycollate, Crosscarmellose sodium and Crosspovidone (2%, 4% and 6%) and three different diluents (mannitol and spray dried lactose) in different concentrations. Eighteen formulations were prepared by using different diluents and evaluated were evaluated for various pre and post compression parameters like angle of repose, bulk density, tapped density, compressibility index, Hausner's ratio, tablet hardness, friability, weight variation, wetting time, water absorption ratio in vitro dispersion time, drug content and in vitro dissolution studies. FTIR and DSC studies revealed that there was no chemical interaction between the drug and the excipients. Formulation L6 was found to be the best on the basis of wetting time, in vitro disintegration time and in vitro drug release. The formulation L6 containing spray dried lactose as diluent and crosspovidone (6%) was found to be the optimized combination. Stability studies were carried out at 250°C±20°C/60%±5% RH and 400°C±20°C/75%±5% RH for formulation L6 for 60 days. The results of stability studies indicated no significant changes with respect to physicochemical properties, in vitro disintegration time, wetting time and in vitro drug release.