Preparation of glycyrrhizic acid-F127/TPGS mixed nanomicelles and its in vivo intestinal absorption in rats / 中草药

ABSTRACT

Objective: To prepare glycyrrhizic acid (GL)-Pluronic F127 (F127)/polyethylene glycol 1000 vitamin E succinate (TPGS) mixed nanomicelles (MMs) and improve oral absorption of GL. Methods: GL-F127/TPGS-MMs was prepared by thin film dispersion method. The encapsulation efficiency and drug loading of MMs were used as evaluation indexes. The formulation and process, including the ratio of F127 to TPGS, the concentration of polymer and GL, hydration temperature and time, were optimized by the single factor experiment. The morphology of MMs was investigated by transmission electron microscopy. The single-pass perfusion model was established in rats to investigate the intestinal absorption characteristics of GL-F127/TPGS-MMs with absorption rate constant (Ka) and apparent absorption coefficient (Papp) as evaluation indexes. Results: The optimal formulation and process of GL-F127/TPGS-MMs were as follows TPGS 180 mg, F127 270 mg, GL 70 mg, hydration temperature 50 ℃ and hydration time 3 h. The prepared GL-F127/TPGS-MMs had good clarity and the particle size, polydispersity index, and Zeta potential were (28.20 ± 5.63) nm, 0.20 ± 0.06, and (-5.24 ± 1.55) mV, respectively. The encapsulation efficiency and drug loading were (97.57 ± 5.29) % and (13.13 ± 0.71) %, respectively. The MMs were spherical with distinct vesicle structure. The absorption of GL in the jejunum segment was significantly higher than that in the ileum segment (P < 0.05). Compared with raw GL, GL-F127/TPGS-MMs had a statistically significant higher absorption rate in the intestinal segment (P < 0.05). Conclusion: The prepared GL-F127/TPGS-MMs could significantly improve the absorption of GL in vivo.