Pharmacokinetic Study Of Qingbingkang In Chickens Under The Condition Of Immunity-inhibition

Qingbingkang(QBK),a new kind of traditional chinesemedicine compound preparation, was designed to treat some clinical immunity-inhibition diseases. This study investigated the pharmacokinetic parameters of QBK in chickens whose immunity functions were inhibited by Cyclophosphamide, using a method of the pharmacodynamic-effect index releated to the rate of NO in serum. Based on the results, the mechanism of QBK regulating the immunity was explored.Result:The results of Dose—response showed that QBK could increase the content of NO in chickens with immunity-inhibition markedly, and the increasing rate of NO is releated to the dose positively, which indicated that the immunity and anti-disease ability could be strengthened by modulating the level of NO in surem of chickens.In a group of a single dose adminitration to the chickens with immunity-inhibition,the pharmacodynamic parameters were as follow, Xmin=2.61g/kg, t1/2ka(E) =0.61h, tp (E)=1.82h, t1/2b eE)=3.25h. The mathematical model based on the remnant-quantity time curves was fitted with one-order absorption, two-compartment open-model, the formula was C=24.221e-0.931t+3.485e-0.012t-(-27.705) e-1.166t. Other apparent pharmacokinetic parameters were t1/2α=0.744h, t1/2β=55.887h, K12=0.521h-1, K21=0.393h-1, Kel=0.029h-1, AUC=283.273mg/l-1.h, a=0.931h-1,β=0.012h-1, Ka=1.166h-1. In conclusion, the pharmacokinetics of QBK in chickens receiving a 5-days dose of 10 g/kg by oral administration revealed a rapid absorption, high distribution and slow elimination, which indicated that a dose of 10 mg/kg of QBK administered twice daily may be appropriate for use in chickens.