Burmańczuk Artur, Tomasz Grabowski, Gbylik-Sikorska Małgorzata, Gajda Anna, Kowalski Cezary
Department of Pharmacology, Faculty of Veterinary Medicine, University of Life Sciences, 20-033 Lublin, Poland.
Polpharma Biologics, 80-172 Gdańsk, Poland.
J Vet Res. 2017 Apr 4;61(1):37-43. doi: 10.1515/jvetres-2017-0005. eCollection 2017 Mar.
There are many veterinary products containing β-lactam antibiotics which are used for mastitis treatment in cows. The aim of the study was to determine whether mastitis could have any effect on amoxicillin (AMX) or penicillin G procaine (PEN) withdrawal period from milk, in the context of current maximum residue limits established by the European Commission.
The study was conducted on 17 dairy Black and White cows with clinical mastitis during the lactation period. The first group (n = 8) received 200 mg of amoxicillin (AMX), whereas the second group (n = 9) received 200,000 IU/mg of penicillin G procaine (PEN) by intramammary administration. For the measurement of AMX and PEN concentrations in milk, the liquid chromatography tandem mass spectrometry method was applied. Pharmacokinetic calculations were performed using Phoenix WinNonlin 6.4 software.
The determined AMX and PEN half-life values in the mammary gland suggest that the drug withdrawal is at a level of 99.9% within 81 h (≈3.5 days) and 116 h (≈5 days) after administration of AMX and PEN, respectively. The present research indicates that, at 60 h after administration, the average PEN concentration in the milk from cows with clinical signs of mastitis may still reach 4.96 g/kg and that of AMX can even be 6.92 g/kg.
The results obtained confirm that, in mastitis cases, a 72-h withdrawal period is sufficient for elimination of AMX to a lower level than the established maximum residue limit (MRL) values. However, in the case of PEN, at 69 h after administration, the drug concentration may be close to that of the determined MRL.
有许多含有β-内酰胺类抗生素的兽用产品用于奶牛乳腺炎的治疗。本研究的目的是在欧盟委员会规定的当前最大残留限量范围内，确定乳腺炎是否会对阿莫西林（AMX）或普鲁卡因青霉素G（PEN）的牛奶停药期产生影响。
本研究对17头泌乳期患有临床乳腺炎的黑白花奶牛进行。第一组（n = 8）通过乳房内给药接受200毫克阿莫西林（AMX），而第二组（n = 9）接受200,000 IU/毫克普鲁卡因青霉素G（PEN）。采用液相色谱串联质谱法测定牛奶中AMX和PEN的浓度。使用Phoenix WinNonlin 6.4软件进行药代动力学计算。
所测定的乳腺中AMX和PEN的半衰期值表明，分别在给予AMX和PEN后81小时（约3.5天）和116小时（约5天）内，药物清除率达到99.9%。本研究表明，给药后60小时，患有乳腺炎临床症状奶牛的牛奶中PEN平均浓度仍可能达到4.96微克/千克，而AMX甚至可达6.92微克/千克。
所得结果证实，在乳腺炎病例中，72小时的停药期足以将AMX清除至低于既定最大残留限量（MRL）值的水平。然而，对于PEN，给药后69小时，药物浓度可能接近所测定的MRL值。
