Characterization of biopolymer-based systems obtained by spray-drying for retinoic acid controlled delivery

Abstract

Novel carrier-based delivery systems have been strategically designed and developed to beneficiate retinoic acid (RA) as medical agent. The final purpose is to deal with the factors which hamper RA efficacy (e.g. short half-life, low absorption in the intestine and severe side effects). The present work proposes the inclusion of RA into arabic gum, modified chitosan and alginic acid sodium microcapsules using spray-drying technology. The product yield varied between 26 and 38% for empty and RA-loaded microcapsules. Spherical microcapsules with a rough, slightly rough and smooth surface (according to the encapsulating agent) and with an average size in the range of 3.279 to 10.880 mu m were obtained. Controlled release studies evidenced the fastest RA release (in 99 min) for the modified chitosan formulation, while alginic acid sodium microcapsules enabled a RA release for >7 h. The main kinetic release models, based on different mathematical functions, were applied to RA. The Weibull model revealed to be the most appropriate to characterize the RA release profiles.