In vitro and in vivo evaluation of curcumin loaded hollow microspheres prepared with ethyl cellulose and citric acid

Curcumin (CUR) demonstrates a variety of biological activities; however, the poor oral bioavailability limits its clinical application. The objective of this study was to develop and evaluate characteristics and bioavailability of hollow microspheres loading curcumin (CUR-HPs). CUR-HPs were prepared by solvent diffusion and evaporation method. The effect of viscosity of ethyl cellulose (EC), amount of EC, citric acid (CA) and CUR on physicochemical characteristics and in vitro release profile of CUR-HPs were evaluated. Scanning electron microscopy (SEM) showed microspheres had smooth surfaces with hollow structures. The yield of CUR-HPs was (96 1.80) %. The floating rate at 24 h was (89.67 +/- 4.91) % and the drug loading was (3.41 +/- 0.21) %. Nearly 95% of CUR was released from the HPs at 24 h. In vitro release profiles of CUR-HPs fitted the Korsmeyer et al.'s equation and indicated that CUR was released through the combination of diffusion and erosion mechanisms. The bioavailability of CUR-HPs was 12-fold higher than that of CUR The peak time was delayed for 7.5 h and peak concentration of CUR-HPs was 3.21 times than that of free CUR The CUR-HPs might be a promising strategy to achieve sustained release and increase oral bioavailability of CUR. (C) 2018 Elsevier B.V. All rights reserved.