ABSTRACT
OBJECTIVE: To investigate the pharmacokinetics of triptolide gels, nanoemulsions and nanoemulsion gels by simultaneous skin and blood microdialysis in rats. METHODS: The microdialysis systems include linear probes and vascular probes which are used for measuring the recovery of triptolide in skin and blood, respectively. Linear probe and vascular probe were implanted in SD rats after abdominal hair removal. Triptolide gels, nanoemulsions and nanoemulsion gels were administered to SD rats. The probe was continuously perfused with PBS(pH 7.4) at a flow rate of 3 μL•min-1. Dialysate samples were collected every 30 min and continuously performed for 12 h. The dialysis samples were determined by LC-MS. RESULTS: The AUC0-t(s) of triptolide nanoemulsions and nanoemulsion gels were significantly higher than those of triptolide gels in skin and blood. Moreover, compared with the concentration of triptolide nanoemulsions in skin and blood, triptolide was released more smoothly from nanoemulsion gels, providing a sustained release effect and an improved bioavailability. CONCLUSION: The technique of simultaneous skin and blood microdialysis is able to detect the concentration of drug in the skin and blood of rats, which provides a new method for the pharmacokinetic study of tripolide.