Formulation and In-vitro Evaluation of Mesalamine Loaded Magnetic Microspheres for Colon Drug Delivery

Abstract

Magnetically responsive Mesalamine microspheres were prepared using Eudragit L100-55 and sodium alginate polymers via the solvent evaporation technique. Calibration curves in 0.1N HCl and phosphate buffers (pH 6.8 and 7.4) confirmed linearity and adherence to Beer-Lambert's law, with R² values of 0.999. FTIR spectra verified compatibility of Mesalamine with polymers, demonstrating characteristic functional groups without interaction. The formulations were evaluated for micromeritics, entrapment efficiency, particle size, drug content, drug release percentage, and kinetics. Results showed the drug release followed zero-order kinetics, supported by high correlation coefficients between time and cumulative drug release for all nasal in situ gel formulations. Formulation F3 was identified as optimal, with a particle size of 182 nm, 95% drug entrapment efficiency, and 75.62% drug release at 10 hours. The release mechanism followed Super case-II transport with an 'n' value of 1.669. These findings indicate that mesalamine-loaded magnetic microspheres have significant potential as a targeted drug delivery system, enhancing drug bioavailability and localized release.