Implementation of the Box–Behnken Design in the Development and Optimization of Methotrexate-Loaded Microsponges for Colon Cancer

<i>Methotrexate (MTX) is an effective anticancer agent with limited water solubility, resulting in lower absorption in the gastrointestinal tract when administered orally. The present aim of the study is to construct sustained-release formulation of MTX-loaded microsponges with enhanced intestinal absorption and bioavailability using a quasi-emulsion solvent diffusion method. The Box-Behnken design (BBD) was adopted for this purpose. Particle size, encapsulation efficiency (EE), Q 2 h % (% drug release in 2 h), and Q 24 h % (% drug release in 24 h) were used as dependent factors, and polyvinyl alcohol, solvent, and stirring speed were used as independent factors. The prepared microsponges were characterized to assess their particle size and encapsulation efficacy (%). Attenuated total reflectance-Fourier transform infrared spectroscopy and differential scanning calorimetry were used to verify the compatibility study. Moreover, the cytotoxicity study was conducted on the HT-29 cell line. The optimized formulation exhibited a % encapsulation efficacy of 87.191% and a particle size of 2.176 µm. Furthermore, the optimized formulation demonstrated sustained drug release (85.71%) in Simulated Gastric Fluid (SGF) fluid at different pHs 1.2, 6.8, and 7.4. The stability study of the optimized formulation revealed good stability in terms of drug release, % encapsulation efficacy, and particle size. The results of the optimized formulation demonstrated that the viability of HT-29 colon cancer (CC) cells was dose-dependently decreased by MTX-loaded microsponges. BBD was successfully employed for the development and optimization of MTX microsponges filled in Eudragit S-100-coated hard gelatin capsule, depicting their potential release of MTX from microsponges capsule only at the colonic region and found to be potential carrier system for CC.</i>