Pharmacokinetic and pharmacodynamic study of triptolide-loaded liposome hydrogel patch under microneedles on rats with collagen-induced arthritis

Triptolide (TP), a major active component of Triptelygium wilfordii Hook.F. (TWHF), is used to treat rheumatoid arthritis (RA). However, it has a narrow therapeutic window due to its serious toxicities. To increase the therapeutic index, a new triptolide-loaded transdermal delivery system, named triptolide-loaded liposome hydrogel patch (TP-LHP), has been developed. In this paper, we used a micro-needle array to deliver TP-LHP to promote transdermal absorption and evaluated this treatment on the pharmacokinetics and pharmacodynamics of TP-LHP in a rat model of collagen-induced arthritis (CIA). The pharmacokinetic results showed that transdermal delivery of microneedle TP-LHP yielded plasma drug levels which fit a one compartment open model. The relationship equation between plasma concentration and time was C=303.59 x (e(-0.064t)-e(-0.287t)). The results of pharmacodynamic study demonstrated that TP-LHP treatment mitigated the degree of joint swelling and suppressed the expressions of fetal liver kinase-1, fetal liver tyrosine kinase-4 and hypoxia-inducible factor-1a in synovium. Other indicators were also reduced by TP-LHP, including hyperfunction of immune, interleukin-1/3 and interleukin-6 levels in serum. The therapeutic mechanism of TP-LHP might be regulation of the balance between Thl and Th2, as well as inhibition of the expression and biological effects of vascular endothelial growth factor. (C) 2015 Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.V.