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.
ABSTRACT
Objective: To compare intestinal absorption features of berberine hydrochloride phospholipid solid dispersions (BBH-PSD) by rat single-pass perfusion model, and to explore the mechanism of berberine bioavailability increasing mechanism by phospholipid solid dispersion technology. Methods: The single-pass perfusion model was established in rats, the concentration of berberine in intestinal perfusion was determined by HPLC, and phospholipid solid dispersion technology promoting intestinal absorption of berberine was investigated. Results: Compared with berberine, BBH-PSD could promote much more absorption of berberine in various intestinal segments, especially in jejunum, and the mechanism was related to improving permeability and strengthen simple diffusion of berberine. The Ka and Papp values of BBH and BBH-PSD in jejunum were obviously higher than BBH (P < 0.05); When the volumetic flow rate of BBH-PSD was 0.2, 0.4, and 0.8 mL/min, Ka and Papp were both higher than BBH (P < 0.05); The increasing mass concentration was not obvious to intestinal absorption of BBH, while the increasing mass concentration of BBH-PSD obviously increased the intestinal absorption of BBH (P < 0.05). Conclusion: Intestinal absorption characteristics of berberine phospholipid solid dispersion is beneficial to improve berberine oral bioavailability, and it can provide a scientific basis for the development of new dosage forms of berberine hydrochloride.
ABSTRACT
Objective: To study the rat intestinal absorption characteristic of puerarin loaded O-carboxymethyl chitosan (CMCS) microspheres in situ. Methods: Single-pass intestinal perfusion (SPIP) model was used for rat in situ and HPLC to determine the concentration of puerarin. The effects of different perfusion rate, drug concentration, and intestinal segments on intestinal absorption were investigated, and the absorption characteristics of the puerarin and puerarin loaded O-CMCS microspheres were compared. Results: Perfusion rate had significant effect on the absorption rate constants (Ka) and the apparent absorption coefficient (Papp) (P 0.05); Ka and Papp of drug loaded microspheres in jejunum and ileum showed no significant difference, but they were significantly higher than that in duodenum (P < 0.05); The drug loaded microspheres and puerarin had the significant difference in Ka and Papp in jejunum (P < 0.05). Conclusion: The absorption mechanism of puerarin in the microspheres is passive diffusion, puerarin is absorbed well in jejunum and ileum, and puerarin loaded O-CMCS microspheres can significantly improve the absorption of puerarin.