α-Tocopherol acetate-loaded chitosan microparticles: Stability during spray drying process, photostability and swelling evaluation

Chitosan/alpha-tocopherol acetate/Aloe vera microparticles were prepared by spray drying and characterized concerning their size, drug content, chemical integrity and photostability. The particles were spherical, with a rough surface, micrometric (D[4,3] = 9.59 mu m), unimodal and polydisperse (SPAN of 1.12). The final alpha-tocopherol acetate concentration in the powder was 91% of the expected amount. FTIR analyses confirmed that alpha-tocopherol acetate dose not suffer oxidation during the spray drying process. Furthermore, alpha-tocopherol acetate photostability in the microparticles was evaluated for 7 days in a UVC light chamber. The microparticies were capable of maintaining the concentration of alpha-tocopherol acetate for a longer time than a commercially available pulverized form of alpha-tocopherol acetate. When added to a hydrophilic gel, particles tend to partially swell and form a second population of larger particles. The second population formed was less representative. (C) 2015 Elsevier B.V. All rights reserved.