Formulation and in Vitro Evaluation of Methotrexate -Loaded Solid Lipid Nanoparticles

The present study was aimed at the formulation and in vitro evaluation of Methotrexate-loaded Solid Lipid Nanoparticles (SLNs) to enhance drug delivery, improve stability, and achieve controlled release. Methotrexate, a poorly water-soluble anticancer drug, exhibits limited bioavailability, which can be improved through nanocarrier-based systems. SLNs were prepared using glyceryl monostearate as the lipid matrix and Tween 40/Span 80 as surfactants by a suitable lipid-based formulation technique. Four formulations (F1–F4) were developed and evaluated for physicochemical properties, particle size, zeta potential, entrapment efficiency, in vitro drug release, and stability studies. FTIR studies indicated no significant drug–excipient interactions, confirming compatibility. The optimized formulation (F4) exhibited the smallest particle size (119 nm), highest entrapment efficiency (85.6%), and highest zeta potential (-25.8 mV), indicating improved stability and effective drug encapsulation. In vitro release studies demonstrated sustained drug release up to 8 hours, with F4 showing maximum release (97.53%). Stability studies confirmed that the optimized formulation remained stable under different storage conditions over three months with minimal variation in drug content. The study concluded that SLNs are a promising drug delivery system for Methotrexate, significantly improving its release profile, stability, and encapsulation efficiency. Formulation F4 was identified as the optimized batch based on overall performance.