Pharmacokinetics of phillyrin and forsythiaside following iv administration to Beagle dog.

The objective of the present study was to firstly investigate the in vivo pharmacokinetics of phillyrin and forsythiaside in beagle dog. On I.V. administration, a rapid distribution was observed and followed by a slower elimination for phillyrin and forsythiaside. The mean t(1/2Z) was 49.99, 34.87 and 43.81 min for 0.19, 0.70 and 1.43 mg/kg of phillyrin, and 60.90, 64.30, 57.99 min for 0.62, 1.39 and 5.52 mg/kg of forsythiaside respectively. And the AUC(o-t) increased linearly from 36.51 to 160.22 microg x min/ml of phillyrin and from 50.63 to 681.08 microg x min/ml after the three dosage administrated. In the range of the dose examined, the pharmacokinetics of phillyrin and forsythiaside in beagle dog was based on first order kinetics. Although both drugs were widely distributed to various tissues in the dog, no concerns about extensive binding to tissues that may be consumed by the public should a dog be exposed to phillyrin and forsythiaside according to the rapid elimination.