Exploring the Solvent-Anti-solvent Method of Nanosuspension for Enhanced Oral Bioavailability of Lovastatin

Lovastatin is an antilipidemic drug that belongs to the class of statins that has poor oral bioavailability due to its low solubility and variable dissolution rate. The main aim of this study was to enhance the solubility and dissolution rate of the drug and understand its oral bioavailability.

Lovastatin nanosuspension was formulated using a solventanti-solvent method using a probe sonication technique. A nanosuspension was prepared, using hydroxypropyl methylcellulose (HPMC) K15M and pluronic F68 as stabilizers. The formulated nanosuspensions were characterized for particle size, polydispersity index (PDI) zeta potential, surface morphology, and in vitro release rate. Further, an in vivo bioavailability study and stability studies were also performed.

Optimized formulation showed a particle size of 127±0.01 nm, a PDI of 0.492±0.001, and a zeta potential of -37.9 mV, which indicates good stability. Morphological study showed that the particles were in the nano range. The drug content was found to be in the range of 73-87%. In vitro release revealed much faster release of the drug in one hour compared to the pure drug and its marketed formulation. In vivo bioavailability study was carried out in Wistar rats, which showed improvement in bioavailability by approximately 2.5 folds compared with the marketed formulation. Stability studies indicated that the optimized formulation F2 was more stable at 4°C±2°C.

The prepared lovastatin nanosuspension showed improvement in solubility, dissolution rate, and oral bioavailability compared to the pure drug and its marketed formulation. Hence, lovastatin nanosuspension may be a potentially valuable tool for improving the oral bioavailability of lovastatin.