Formulation and Physicochemical Characterization of ChitosanCoated Simvastatin Nanoparticles

Abstract

Simvastatin is an effective antihyperlipidemic agent whose clinical utility is limited by poor aqueous solubility, low gastrointestinal absorption, and extensive first-pass metabolism, resulting in reduced oral bioavailability. This study aimed to formulate and characterize chitosan-coated simvastatin nanoparticles as a strategy to improve its physicochemical performance and controlled release properties. Nanoparticles were prepared using the ionic gelation method involving electrostatic interaction between chitosan and sodium tripolyphosphate. The developed formulation was evaluated by in vitro drug release studies, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The release profile demonstrated a biphasic pattern with an initial burst release during the early phase, followed by sustained drug release reaching approximately 70–75% over 300 minutes, indicating effective controlled-release behavior. SEM analysis showed clear morphological transformation from loosely aggregated crystalline simvastatin particles to denser and more cohesive nanoparticulate structures after chitosan coating, confirming successful encapsulation. FTIR spectra retained the characteristic peaks of both simvastatin and chitosan with only minor shifts in band positions, suggesting structural integrity of the drug and absence of significant chemical incompatibility between formulation components. The combined findings indicate that chitosan coating improved the physicochemical characteristics of simvastatin while providing sustained release potential. Therefore, chitosan-coated simvastatin nanoparticles represent a promising oral nanocarrier system for enhancing simvastatin delivery and therapeutic performance.