Development, characterization and Caco-2 cells absorption of curcumin solid dispersion for oral administration

Abstract

Curcumin is an active dietary compound. However, its low solubility and rapid metabolism limit its absorption in the gastrointestinal (GI) tract and reduces its systemic bioavailability. To overcome these drawbacks, curcumin solid dispersion (CSD) was developed employing polyvinylpyrrolidone (PVP) as a carrier without and with soybean phospholipids (SP) as a co-carrier and prepared using a melting solvent method. The influence PVP and SP on physicochemical properties and in vitro permeability of CSD was investigated. Curcumin in all developed CSD demonstrated amorphous state as confirmed by X-ray diffraction. Spherical particles of ∼140 nm and ∼190 nm were obtained when CSD without and with SP was diluted with water. Consequently, CSD without and with SP possessed significantly greater curcumin water solubility of ∼4200-fold and ∼6500-fold, respectively, as compared to free curcumin, which leading to enhanced curcumin absorption across Caco-2 cell. The dissolution studies, both in 0.1N HCl and phosphate buffer pH6.8, of CSD showed that curcumin was quickly and completely dissolved within 5 min. Caco-2 cell permeation studies revealed that CSD with SP presented a lag time with slightly lower curcumin absorption than CSD without SP. Moreover, the physical and chemical stability of CSD was found to be stable for up to 6 months at 4 °C and room temperature. From these findings, CSD could be beneficial for enhancing the oral absorption profiles of curcumin.