Tissue distribution of cloxacillin after intramammary administration in the isolated perfused bovine udder

Abstract

BackgroundVarious intramammary suspensions containing cloxacillin benzathine are registered for use in cattle as antibiotics for intramammary use at drying off. To ensure antibacterial efficacy, the glandular tissue concentration of an antimicrobial agent must be sufficient. Since the possibilities to measure concentrations in the different areas of the glandular tissue in vivo are very limited, it was the aim of the present study to examine the distribution of cloxacillin in vitro using the isolated perfused bovine udder.MethodsMammary glands taken at slaughter from healthy lactating cows were perfused in vitro with warmed and gassed Tyrode solution. 600 mg cloxacillin benzathine were administered as Orbenin Extra Dry Cow by the intramammary route to six front and rear quarters each. Samples of glandular tissue - at different distances from and vertical to the teat right up to the udder base - were gathered from the treated quarters after 6 h. Perfusate was also sampled before and hourly after treatment for 6 h. The cloxacillin content of the tissue samples and perfusate samples was analysed by high performance liquid chromatography.ResultsThe concentration of cloxacillin in the glandular tissue of front quarters measured 6 h after administration tended to decrease with increasing vertical distance from the teat. The decrease pattern of the concentration was not quite clear in rear quarters. A considerable variation in the tissue concentrations of cloxacillin was obvious, which reflects in vivo conditions. The concentrations measured in the perfusate samples were below the limit of quantification at all time points, indicating limited absorption of the antibiotic from the glandular tissue.ConclusionAfter intramammary administration of the dry off product containing cloxacillin benzathine concentrations of more than 0.5 μg/g (MIC) were reached in all regions of the front and rear quarters.

Determination of cloxacillin residues in dairy cows after intramammary administration

“…Such assumptions would confirm the hypothesis about special role of fat in the elution of CLO from the mammary gland (Ziv, ; López et al ., ). However, the possible role of fat in the elimination and distribution of CLO in the udder tissue has not been raised in earlier works (Kietzmann et al ., ).…”

Characterization and in vivo evaluation of nanocapsules loading 99mTc-MIBI for intramammary study

“…Also Kietzmann et al [28] detected cloxacillin benzathine by HPLC in mammary gland and blood, at 6 h after intramammary administration of the antibiotic suspension in isolated perfused bovine udder. The concentrations measured in the perfusate samples were below the limit of quantification at all time points, indicating limited absorption of the antibiotic from the glandular tissue at that time.…”

Comparative Veterinary Pharmacokinetics

“…This phenomenon worth considering as drug residues will be present also in the milk and the edible tissues raising a public health issue if the animal must be slaughtered. Less lipophilic substances are absorbed usually in a negligible amount, especially in healthy animals as proved about cloxacillin in vitro by Kietzmann et al (2010) …”