Formulation and In-Vitro Evaluation of Gliclazide Microspheres Using Chitosan and Sodium Alginate by Ionic Gelation Method

Abstract

Gliclazide-loaded chitosan–sodium alginate microspheres were developed by ionic gelation to obtain sustained oral drug release. Six formulations (F1–F6) were prepared by varying polymer concentrations while maintaining gliclazide, sodium tripolyphosphate and Tween 80 levels constant. The microspheres were characterized for micromeritic properties, percentage yield, entrapment efficiency, drug loading, swelling, particle size, surface morphology, drug content and in-vitro drug release. Drug–polymer compatibility was assessed by Fourier transform infrared spectroscopy and differential scanning calorimetry. F4 showed the most favourable overall characteristics, with 92.4% yield, 90.3% entrapment efficiency, 10.86% drug loading and 106% swelling at 8 h. The optimized formulation showed a cumulants diameter of 662.1 nm, PDI 0.402 and zeta potential of −26.77 ± 0.25 mV. Drug release from F4 was 9.0% at 1 h and 94.2% at 24 h. The Korsmeyer–Peppas model provided the best fit (R² = 0.9994; n = 0.769), indicating anomalous/non-Fickian release. Compared with the marketed modified-release product, F4 showed 24-h release of 94.2% versus 93.5%, with f₁ = 1.38 and f₂ = 95.28. Short-term stability over 45 days showed only minor changes in the evaluated characteristics. The findings indicate that the optimized chitosan–sodium alginate microspheres can provide prolonged gliclazide release over 24 h.