Fabrication of pH-responsive dextran- modified polylactic acid core-shell microparticles for antidiabetic drug delivery.

Abstract

Abstract Glipizide, a low-cost antidiabetic drug, known for its fast-acting nature and reduced risk of hypoglycemia. However, its usage is limited by its short acting nature and non-selectivity. In our study we demonstrate modified dextran coated glipizide loaded PLA (Polylactic acid) microspheres capable of targeted drug release at intestinal region. These particles show improved mucoadhesion in presence of glycidyltrimethyl ammonium chloride modified dextran (GT-dextran) as an outer coating. To achieve this glipizide encapsulated PLA, microspheres of size 27.09 ± 6.55 µm were fabricated using emulsion solvent evaporation followed by GT-dextran surface coating using dipping method. NMR, FT-IR, FESEM, TGA, and Zeta Potential confirmed the presence of GT-dextran coating on the surface of PLA particles. Controlled release of glipizide from the PLA matrix was achieved for the fabricated polymer particles. GT-dextran coating increases the size of the GI-PLA particles by 14.01 % with size 17.17 ±1.33 µm, along with 57.47 ± 2.7% encapsulation efficiency. The release behavior was assessed at three different pH, demonstrating slow release at of 8.76 ± 0.93 % low pH (1.5) and fast release of 92.4 ± 7.32 % at pH 7.2. The desired controlled release profile was achieved, with 68.45 ± 11.01% at pH 9.2 over a time of 48-hours. The fabricated pH-responsive core-shell type microspheres exhibit great potential as a targeted and controlled drug delivery system for antidiabetic therapy.