| Milbemycin Oxime has the characteristics of broad spectrum insecticidal activity, better absorption and high safety as a specific drug for the treatment of Dirofilaria immitis and intestinal parasites in dogs and cats, which is widely used to prevent dogs and cats from parasites in clinical. It is effective to the treatment of toxocara in cats combined with Praziquantel. The pharmacokinetic characteristics were evaluated by study on Milbemycin Oxime-Praziquantel tablets pharmacokinetic in cats in this paper, in order to provide experimental evidence for the design of new drugs and its application in clinical veterinary and guide the rational use of drugs in clinical.Sixteen adult cats(8♂+8♀) were randomly divided into two groups, the pharmacokinetics of test substance and reference substance Milbemycin Oxime-Praziquantel tablets were studied in cats by oral administration, using a single dose of parallel test(4 mg/kg·b.w. Melbemycin Oxime).The concentrations of Milbemycin Oxime and Praziquantel in blood plasma were determined by high performance liquid chromatography (HPLC) method after administration and its pharmacokinetic parameters were obtained by Winnonlin5.2 software.The main pharmacokinetic parameters of reference substance were as follows after oral administration as above in cats. The mean T1/2β, Tmax, Cmax, AUC and MRT of Milbemycin Oxime were respectively 20.08 h,6.00 h,764.43 ng/mL,15.00 ng/L/h and 18.60 h; The mean T1/2β, Tmax, Cmax, AUC and MRT of Praziquantel were respectively 6.27 h,3.88 h,1018.25 ng/mL, 8.69 ng/L/h and MRT 6.56 h. Compared with Praziquantel, Milbemycin Oxime absorbed and eliminated in cats were slowly.The main pharmacokinetic parameters of test substance were as follows after oral administration as above in cats. The mean T1/2β, Tmax, Cmax, AUC and MRT of Milbemycin Oxime were respectively 15.07 h,5.25 h,806.65 ng/mL,15.18 ng/L/h and 17.47 h, and the relative bioavailability was 101.20%. The mean T1/2β, Tmax, Cmax, AUC and MRT of Praziquantel were respectively 11.11 h,5.25 h,880.47 ng/mL,9.64 ng/L/h and 10.52 h, and the relative bioavailability was 119.16%.Compared with reference substance, the elimination half-life of milbemycin oxime was significantly shorter, and peak time of praziquantel was significantly delayed (0.01<P<0.05) in test substance, other main pharmacokinetic parameters were not significant (P>0.05). Results indicated that milbemycin oxime test substance are similar with reference substance for pharmacokinetic characteristics in cats with oral administration, which also confirmed they have similar clinical efficacy. |
