Formulation design and evaluation of a self-microemulsifying drug delivery system of lovastatin

Self-microemulsifying drug delivery system (SMEDDS) of lovastatin was aimed at overcoming the problems of poor solubility and bioavailability. The formulation strategy included selection of oil phase based on saturated solubility studies and surfactant and co-surfactant screening on the basis of their emulsification ability. Ternary phase diagrams were constructed to identify the self-emulsifying region. Capryol 90 (20 %) as oil, Cremophore RH40 (40 %) as surfactant and Transcutol P (40 %) as co-surfactant were concluded to be optimized components. The prepared SMEDDS was characterized through its droplet size, zeta potential, emulsification time, rheological determination and transmission electron microscopy. The optimized formulation exhibited 94 % in vitro drug release, which was significantly higher than that of the drug solution. In vivo studies using the Triton-induced hyperlipidemia model in Wistar rats revealed considerable reduction in lipid levels compared to pure lovastatin. The study confirmed the potential of lovastatin SMEDDS for oral administration.