奶牛乳房内灌注头孢噻呋钠的消除动力学研究

在奶牛乳房内灌注头孢噻呋钠后，采用超高效液相色谱一串联质谱法测定牛乳中头孢噻呋的浓度，对其消除动力学进行了研究。3头实验奶牛按每个乳房0．3g头孢噻呋灌注，牛乳中药物达到的最高浓度Cmax=107．89μg／mL，达峰时间Tmax=8h，药物半衰期T1/2=13．97h。在乳房内用药后的最初56h内，头孢噻呋浓度快速下降；最后一次给药88h后，所有乳腺中头孢噻呋的浓度都低于允许限量（0．1μg／mL）。故建议头孢噻呋在牛奶中的休药期为4d。

Elimination kinetics of ceftiofur Sodium in dairy cows after intramammary administration

A UPLC - MS/MS method was adopted for detection of ceftiofur sodium residues in raw milk after intramammary administration, and elimination kinetics study of ceftiofur sodium in three dairy cows at a dose of 0.3 g per udder. Cmax = 107. 89 μg/mL, Tmax = 8 h, T1/2 = 13.97 h. Ceftiofur concentrations declined rapidly during the first 56 hours after intramammary administration. Ceftiofur concentrations in milk from all mammary gland quarters were less than the tolerance （0.1 μg/mL） at 88 hours after last administration. On the basis of above - mentioned results, it was recommended that milk from treated mammary gland quarters should be discarded for a minimum of 4 days after intramammary administration of ceftiofur sodium.