Enhanced oral bioavailability of curcumin via a solid lipid-based self-emulsifying drug delivery system using a spray-drying technique

Abstract

In this study, a novel liquid self-emulsifying drug delivery system (SEDDS) containing curcumin was formulated and further developed into a solid form by a spray drying method using Aerosil 200 as the solid carrier. The optimum liquid SEDDS consisted of Lauroglycol Fcc, Labrasol and Transcutol HP as the oil phase, the surfactant and the co-surfactant at a weight ratio of 15.0 : 70.8 : 14.2 (w/w/w), respectively. There was no difference in droplet size between the emulsions obtained from the liquid and solid forms of SEDDS. Solid state characterization of the solid SEDDS was performed by scanning electron micrograph (SEM), differential scanning calorimetry (DSC), and X-ray powder diffraction (XRPD). The drug formulated in the solid SEDDS was quickly and completely dissolved within 5 min, both in 0.1 N HCl and phosphate buffer pH 6.8 dissolution media, whereas crude curcumin powder was significantly less dissoluble. The solid SEDDS formulation was stable for at least 3 months at 40°C with 75% relative humidity. After oral administration to rats, curcumin in the solid SEDDS resulted in significant improvement in in vivo absorption compared with that of curcumin powder. As the dose of curcumin formulated in solid SEDDS increased from 25 to 100 mg/kg, the C(max) and area under the drug concentration time curve (AUC) of curcumin were increased by 4.6 and 7.6 times, respectively. However, the over-proportional increase in the AUC in the higher dose group might be due to underestimation of AUC in the lower dose group. In conclusion, this solid SEDDS is a promising solid dosage form for poorly water-soluble curcumin.