Effects of combined administration of Paeoniae Radix Alba on local pharmacokinetics of six aconite alkaloids by skin microdialysis in vivo

The Aconiti Radix Cocta gel and Aconiti Radix Cocta combined with Paeoniae Radix Alba gel were administered to mice. Physiological saline was taken as perfusate. The perfusion rate was 2 μL•min⁻¹ and the microdialysis samples were collected every 0.5 h intervals for eight times. The six aconitine alkaloids concentration in perfusate were determined by HPLC-MS/MS. The concentration-time curves were plotted, and the pharmacokinetic parameters were calculated and analyzed by SPSS. The effects of Paeoniae Radix Alba on transdermal permeation role of six aconitine alkaloids in herb couple of Paeoniae Radix Alba-Aconiti Radix Cocta were investigated. According to the results, Tmax of the three mono-ester aconitum alkaloids of Aconiti Radix Cocta combined with Paeoniae Radix Alba groups were shortened, meanwhile, Cmax and AUC of benzoylaconine and benzoylhypaconine were increased. However, AUC of the three diester-type alkaloids were reduced, with Tmax of hypaconitine prolonged and Cmax lowered. The study suggested that the combined administration of Aconiti Radix Cocta and Paeoniae Radix Alba promoted the transdermal permeation of mono-ester aconitum alkaloids, and inhibited the absorption of parts of diester-type alkaloids. This study proved the decreasing toxicity and increasing efficacy of the combination of Aconiti Radix Cocta and Paeoniae Radix Alba on the transdermal permeation, and provided a reference for studies on the prescription combination regularity and relevant practices.