Production of polycaprolactone-polyethylene glycol-sodium alginate biocomposites for spray drying encapsulation of L-ascorbic acid

L-Ascorbic acid was encapsulated in biopolymers to enhance (1) its encapsulation efficiency and (2) drug release ratio using different pH media. To achieve this goal, we used polycaprolactone (PCL), polyethylene glycol (PEG), and sodium alginate (SA) to prepare drug delivery system and spray dryer as our tool to obtain microspheres. In this manner, the importance of the study was to produce a stable and effective drug encapsulation system by PCL-PEG-SA polymer mixture by spray dryer. First we evaluated the effects of drying conditions and composition on the microencapsulation formulation and in the next stage the most uniformly distributed particles were selected and L-ascorbic acid was loaded. After that, drug encapsulation and drug release studies were performed. Drug release experiments were conducted at different pH solutions (pH 2.5, 7.4, and 9.6). Finally, drug release kinetics was determined by widely used equations to describe the degradation kinetics; zero-order, first-order, Higuchi, Hixson-Crowell, and Korsmeyer-Peppas. Furthermore, L-ascorbic acid release mechanism from microspheres was also determined. The release profiles of three microspheres obeyed the earlier developed kinetic models for performing possible release mechanisms. The Korsmeyer-Peppas model best described each release scenario.