Formulation and Evaluation of Lovastatin Solid Dispersions with Pregelatinised Starch as Newer Superdisintegrant

Solid dispersions of lovastatin were formulated using pregelatinised starch (PGS) as super disintegrant and were further compressed into tablets by using various diluents such as lactose, dicalcium phosphate (DCP) and microcrystalline cellulose (MCC) to enhance the bioavailability. The solid dispersions were prepared by physical mixing, solvent evaporation and kneading methods. The solid dispersions were found to release the drug faster than the pure drug in dissolution media. The rapid release of poorly soluble lovastatin from solid dispersions was influenced by the proportion of polymer and the method employed for its preparation. Among the three methods employed solvent evaporation and kneading methods were found to be suitable for improving the dissolution rate of lovastatin. The release data was fitted to various kinetic models. The release was found to follow first order kinetics. Some of the dispersions prepared by the solvent evaporation method and kneading method were formulated into tablets with various diluents. The tablet preparations containing different diluents were found to release the drug in the order of DCP>MCC>Lactose. The dissolution rate of tablet formulations prepared with lovastatin solid dispersions (FK1, FS4) were found to release the drug at a faster rate than that of tablets prepared with plain drug.