Formulation, Characterization and In-Vitro Drug Release Study of Simvastatin Nanosuspension for Bioavailability Improvement

Abstract

Background: Simvastatin is a poorly water-soluble HMG-CoA reductase inhibitor for which dissolution can limit oral absorption. Nanosuspension technology reduces drug particle size and can increase surface area available for dissolution. Objective: The study aimed to formulate and characterize simvastatin nanosuspensions using poloxamer 188 and poloxamer 407 as stabilizers and to evaluate their in-vitro dissolution behaviour. Methods: Six formulations (F1–F6) containing 5% w/v simvastatin were prepared by high-pressure homogenization. Poloxamer 188 was used at 0.5%, 1.0% and 1.5% in F1–F3, while poloxamer 407 was used at the same concentrations in F4–F6. The nanosuspensions were lyophilized using 1% mannitol as cryoprotectant. Particle size, polydispersity index (PDI), zeta potential, saturation solubility, drug content, SEM, FTIR, DSC, PXRD, dissolution and stability were evaluated. Results: The reported particle sizes ranged from 92.6 to 281.6 nm. F3 showed the smallest reported particle size (92.6 nm), highest saturation solubility (177.50 µg/mL in 0.1 N HCl and 317.6 µg/mL in pH 7.0 phosphate buffer) and drug content of 99.63 ± 0.05%. In pH 7.0 phosphate buffer, the dissolution table reported 99.14 ± 0.19% release for F3 at 60 min, compared with 29.06 ± 0.48% for pure simvastatin. F3 drug content remained 98.72 ± 0.054% after 90 days at 4°C. Conclusion: The findings indicate that high-pressure homogenization with poloxamer 188, particularly F3, improved the in-vitro solubility and dissolution performance of simvastatin. The source thesis contains inconsistencies in selected reported values, and these require verification before journal submission.