Biopolymer‐based microparticles for encapsulation of all‐trans‐retinoic acid

Abstract

This work aims to investigate the potential of complex coacervation technique to encapsulate and protect all‐trans retinoic acid (RA). Gelatin and κ‐carrageenan were used as wall material and pequi oil was employed as a hydrophobic phase. Three formulations with different protein: polysaccharide ratio and pH were defined to produce the microparticles based on the zeta potential and turbidity analysis: (F1) ratio 3:1 and pH 3.5, (F2) ratio 8:1 and pH 3.5, and (F3) ratio 8:1 and pH 5.0. Microparticles were evaluated regarding their morphology, yield, encapsulation efficiency (EE), and stability. The properties of microparticles were mainly affected by the protein: polysaccharide ratio and the turbidity of the mixtures, which is directly related to the protein‐polysaccharide interaction. Formulation 1 showed the optimal values of yield (75.6%), EE (100.2%), and stability (85% of the encapsulated RA remained in the particle). The results demonstrated the high potential of this innovative technique to encapsulate RA for a future application in topical formulations.