Astaxanthin oleoresin (AO) has a number of beneficial physiological functions. However, its sensitivity to light, heat, oxygen and gastric fluids has limited its application. In this paper, we describe the preparation of AO enteric microcapsules by coacervation to improve its stability and enteric solubility, and evaluate their efficacy by measuring the drug loading, encapsulation efficiency, optical microscopic appearance, stability, in vitro release and bioavailability. The results obtained showed that the AO enteric microcapsules possessed a high encapsulation efficiency (85.9%), a satisfactory in vitro release profile, and the ability of the microencapsulated AO to resist the effects of light, heat and oxygen was improved by 2.2-fold, 3.1-fold and 2.4-fold, respectively, during storage. In addition, the bioavailability of AO microcapsules was approximately 1.29-fold higher than AO, which is important for pharmaceutical applications and as a functional food.
Keywords: Astaxanthin oleoresin; complex coacervation; enteric-coated microcapsules; in vitro release study; stability.