Pharmacokinetics And Residues Of Mequindox In Pigs After Dermal Administration

The pharmacokinetic disposition of MEQO was described after a single dermaladministration of 5 mg/kg dose in healthy pigs. MEQO concentration in plasma andtissues was determined by using high-performance liquid chromatography (HPLC).The concentration-time data of the drug in plasma was fitted by using aone-compartment model. The absorption rate constant (K_a) of MEQO was calculated tobe 0.356±0.028 h^-1, and the elimination half-life (t_1/2ke) of the drug was 3.18±0.62 h. Thearea under the plasma concentration-time curve (AUC) was 6.69±1.27μg·mL^-1·h. Thedistribution volume (V_d/F) of MEQO was computed to be 3.34±0.63 l·kg^-1. The totalclearance of MEQO (CL_b) was estimated to be 0.74±0.18 l·h^-1·kg^-1. The time-point ofmaximal plasma concentration of the drug (T_p) was calculated to be 3.52±0.43 h and themaximal plasma concentration of the drug (C_max) was 0.7±0.31μg/mL. After repeateddermal administration at a dose of 5 mg/kg body weight, MEQO could be detected in themuscle, liver, kidney, and skin for 3 days after the last administration. The resultsrevealed that the depletion of MEQO in pigs became rapid, and had a short half-life time.