Soluble starch-blended Ca2+-Zn2+-alginate composites-based microparticles of aceclofenac: Formulation development and in vitro characterization

The present article describes development of starch-blended Ca2+-Zn2+-alginate microparticles of aceclofenac for attaining gastric protection and controlled release delivery. Different formulations (F1 to F7) of microparticles were prepared by ionotropic gelation method and subjected to characterization studies. In vitro drug release studies were performed in 0.1 N HCl (pH 1.2) for initial 2 h and additional 5 h in phosphate buffer (pH 7.4). These microparticles were characterized by SEM, FTIR spectroscopy and XRD analyses. The formulation F7 (prepared using sodium alginate of 300 mg, soluble starch 250 mg, 5% CaCl2 and 1% ZnSO4) was selected as the optimized formulation, which exhibited entrapment efficiency of 85.73%, particle size of 1610 μm and viscosity of 802.16 cps. In vitro drug release from the formulation F7 revealed maximal 38% drug release within 7 h indicating sustained drug release profile from the prepared formulation. Also, in vitro swelling studies revealed maximal swelling within the period of 2 h at pH 7.4 for all these microparticles. The surface morphology studies performed using SEM showed smooth and spherical nature of the microparticles. Evaluation of drug release kinetic indicated fitting as per Korsmeyer-Peppas model and construed drug release via Fickian diffusion mechanism. Drug-excipient interaction studies using FTIR spectroscopy showed no change in characteristic peaks of the drug, while powder XRD revealed absence of sharp crystalline peaks of the drug. Overall, the present investigation corroborated successful development of microparticles of aceclofenac as an effective and cost-effective approach for oral delivery of aceclofenac. Keywords: Polymer composites, Ionotropic gelation, Microparticles, Drug release, Diffusion, Dissolutio