Determining the pharmacokinetics of intramammary antimicrobials in goats can assist in predicting appropriate meat and milk withdrawal intervals for drugs that are effective at treating subclinical mastitis due to non‐aureus Staphylococci during the dry period. Twenty‐four healthy, lactating does were enrolled in this study. Half were administered 300 mg of cephapirin benzathine (ToMORROW, Boehringer Ingelheim Vetmedica, Duluth, GA) via intramammary infusion into each half of the udder. The remaining does had 500 mg cloxacillin benzathine (Orbenin DC, Merck & Co., Rahway, NJ) administered per half. Plasma was collected before treatment and for 7 days post‐treatment followed by analysis via liquid chromatography with tandem mass spectroscopy. Pharmacokinetic parameters were determined using noncompartmental methods via commercial software (MonolixSuite). The mean maximum concentration (Cmax) of cephapirin of 0.073 μg/mL was noted at 7.06 h post‐administration (Tmax). The area under the plasma concentration curve based on the final sampling point (AUClast) was 1.06 h × μg/mL. The mean residence time until the final sampling point (MRTlast) was 13.55 h. Mean terminal half‐life (T½) of cephapirin was 6.98 h. In CLOX does, Cmax was 0.074 μg/mL with a Tmax of 18 h, AUClast was 5.71 h × μg/mL, T½ was 77.45 h, and MRTlast was 65.36 h. Despite both products being formulated with benzathine salts, marked differences were noted in pharmacokinetic parameters including AUC, T1/2, and MRTlast. This data will be used to plan sampling schedules for milk and tissue residue depletion studies for both products.

中文翻译：

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长效头孢匹林和氯唑西林乳山羊乳内给药后的药代动力学

确定山羊乳房内抗菌药物的药代动力学可以帮助预测有效治疗非金黄色葡萄球菌引起的亚临床乳腺炎的药物的适当的肉类和奶类停药间隔葡萄球菌在干燥期间。二十四只健康的哺乳期母犬参加了这项研究。一半的受试者通过乳房内输注方式将 300 毫克苄星头孢匹林（ToMORROW，Boehringer Ingelheim Vetmedica，德卢斯，佐治亚州）注射到每半个乳房。剩下的每半只注射 500 毫克苄星氯唑西林（Orbenin DC，Merck & Co.，Rahway，NJ）。在治疗前和治疗后 7 天收集血浆，然后通过液相色谱和串联质谱进行分析。通过商业软件（MonolixSuite）使用非房室方法测定药代动力学参数。平均最大浓度（C最大限度给药后 7.06 小时观察到头孢匹林浓度为 0.073 μg/mL（时间最大限度）。基于最终采样点的血浆浓度曲线下面积（AUC最后的) 为 1.06 h × μg/mL。到最终采样点的平均停留时间（MRT最后的）为 13.55 小时。平均终末半衰期（时间½）的头孢匹林为 6.98 小时。在 CLOX 中，C最大限度为 0.074 μg/mL，时间最大限度18小时的AUC最后的为 5.71 h × μg/mL，时间½是 77.45 小时，MRT最后的是 65.36 小时。尽管这两种产品均采用苄星烷盐配制，但药代动力学参数（包括 AUC、时间1/2和捷运最后的。该数据将用于规划这两种产品的牛奶和组织残留物消耗研究的采样时间表。