Pharmacokinetic Study of Skin and Blood of Sinomenine-Loaded Microemulsion Gel Based on Double Sites Simultaneous Microdialysis

  OBJECTIVE  To investigate the pharmacokinetics of sinomenine-loaded microemulsion gel (SMG) by skin and blood microdialysis in rats, and explore the pharmacokinetic characteristics of SMG.

  METHODS  An UPLC method for the determination of sinomenine was established, and its specificity, linearity, precision and recovery rate were examined. The probe was implanted after the rats were anesthetized and depilated, then the sinomenine microemulsion gel was applied onto the bare abdominal skin of the rats. The microdialysis technique and UPLC were used to determine the concentration of the drug.

  RESULTS  The results showed that the established method for the determination of sinomenine microemulsion gel was well linear in the range of 0.5-20 μg·mL^-1, and the specificity, degree of precision and recovery rate of the chromatography all conformed to the examination requirements of microdialysis samples.The results of pharmacokinetic study showed that the C_max values of sinomenine in skin and blood were (10.91±3.05) and (6.74±1.91)μg·mL^-1, respectively. The T_max values were (180.00±39.80) and (239.98±40.85)min, respectively. And the AUC_0→t values were (736.51±45.30) and (426.43±30.18)μg·min·mL^-1.

  CONCLUSION  The sinomenine microemulsion gel plays a role in forming skin reservoir through percutaneous penetration, and can control the sustained release of drug.