FORMULATION, CHARACTERIZATION, AND IN VITRO EVALUATION OF BETULINIC ACID-LOADED SOLID LIPID NANOPARTICLES FOR ENHANCED CYTOTOXICITY AGAINST HUMAN CANCER CELL LINES

Abstract

The present study aimed to formulate and evaluate solid lipid nanoparticles (SLNs) loaded with betulinic acid, a poorly water-soluble natural compound with potent anticancer activity. SLNs were prepared using a hot homogenization followed by ultrasonication method, employing glyceryl monostearate as the lipid matrix and Tween 80 as the surfactant. Five formulations (F1–F5) were developed and evaluated for particle size, polydispersity index (PDI), zeta potential, entrapment efficiency, in vitro drug release, and cytotoxicity. Among the formulations, F5 exhibited optimal characteristics with a particle size of 127.5 nm, PDI of 0.189, and zeta potential of –31.6 mV, indicating good physical stability. The entrapment efficiency reached 88.1%, and in vitro release studies showed sustained drug release over 48 hours, with 96.4% cumulative release from F5. Kinetic modeling suggested first-order release kinetics along with Korsmeyer–Peppas behavior. Cytotoxicity studies using the MTT assay against MCF-7, HeLa, and A549 cell lines revealed significantly lower IC₅₀ values for BA-SLNs compared to free betulinic acid, demonstrating enhanced anticancer efficacy. The findings support the potential of SLNs as a promising drug delivery system to improve the solubility, stability, and therapeutic performance of betulinic acid for effective cancer management. Further in vivo studies are warranted for clinical translation.