OBJECTIVETo study the pharmacokinetics and bioavailability of cantharidin in beagle dogs to evaluate the pharmacokinetic parameters and bioavailability of cantharidin in beagle dogs by determining dose-time curve and by comparing with the pharmacokinetics of cantharidin injection.

METHODSix beagle dogs, after protein precipitation by hydrochloric acid, ethyl acetate was applied to extract cantharidin from plasma The plasma concentration of cantharidin in beagle dogs was determined by GC-MS. The WinNonLin program was used to calculate the pharmacokinetic parameters and bioavailability.

RESULTThe main pharmacokinetic parameters of cantharidin by iv in dogs (34 mL x h(-1) x kg(-1)) were AUC (203.5 +/- 23.8) h x microg x L(-1), CL (168.8 +/- 18.6) mL x h(-1) x kg(-1), t1/2 (0.69 +/- 0.03) h. The main pharmacokinetic parameters of cantharidin by op (102 microg x kg(-1)) were: AUC (160.4 +/- 26.9) h x microg x L(-1), CL (649.1 +/- 97.7) mL x h(-1) x kg(-1), t1/2 (0.38 +/- 0.1) h., F (bioavailability) = 26.7% comparing to injection.

CONCLUSIONAs compared with cantharidin injection, the absorption of catharidin by op is poor and the bioavailability is also low, indicating that enhancement of the bioavailability will be beneficial to the clinical application.