Fabrication of compound K-loaded polymeric micelle system and its characterization in vitro and oral absorption enhancement in vivo

Compound K (CK) was formulated as polymeric micelles (PM) using Pluronic® F-127 to enhance the oral absorption of CK, an intestinal bacterial metabolite of ginseng protopanaxadiol saponin. The physicochemical properties of Ck-loaded PM were characterized and an in vitro transport study using the Caco-2 cell system as well as an in vivo pharmacokinetic study using SD rats was carried out. The hydrodynamic mean particle size of CK-loaded PM (CK-PM) was 254 ± 23.45 nm after rehydration and the drug loading efficiency was ca. 99.9%. The FT-IR spectroscopy, X-ray diffraction, differential scanning calorimetry and scanning electron microscopy data supported the presence of a new solid phase in the PM. The P_app value of in vitro Caco-2 cell permeation of CK- PM and the oral absorption of CK was enhanced about 1.2-fold and 2.6-fold compared to CK suspension, respectively, showing that the present PM formulation enabled an enhancement of oral CK absorption.