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

Kietzmann M, Niedorf F, Gossellin J - BMC Vet. Res. (2010)

Bottom Line: The 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.After 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.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute for Pharmacology, Toxicology, and Pharmacy, School of Veterinary Medicine, Hannover, Germany. manfred.kietzmann@tiho-hannover.de

ABSTRACT

Background: Various 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.

Methods: Mammary 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.

Results: The 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.

Conclusion: After 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.

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Related in: MedlinePlus

Cloxacillin concentration (μg/g tissue) in the glandular tissue of rear quarters of the isolated perfused bovine udder measured at constant vertical distances from the teat base 6 h after the intramammary administration of 600 mg cloxacillin benzathine (Orbenin™ extra dry cow) per quarter. Data are given as box plots from six single experiments. The dotted line shows the MIC90 of 0.5 μg/mL against Staphylococcus aureus.
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Figure 2: Cloxacillin concentration (μg/g tissue) in the glandular tissue of rear quarters of the isolated perfused bovine udder measured at constant vertical distances from the teat base 6 h after the intramammary administration of 600 mg cloxacillin benzathine (Orbenin™ extra dry cow) per quarter. Data are given as box plots from six single experiments. The dotted line shows the MIC90 of 0.5 μg/mL against Staphylococcus aureus.

Mentions: The concentration of cloxacillin in the glandular tissue of all front quarters measured 6 h after administration tended to decrease with increasing vertical distance from the teat. Figure 1 shows this on a logarithmic scale. The decreasing pattern of the concentration could be explained by the high variation of the measured concentrations in the teat region. Especially in one udder quarter, a very high concentration of cloxacillin was measured near the teat. Starting with 4.1 μg/g near the teat (median), the concentration declined to 2.8, 2, 4 and 1.7 μg/g at distances of 8, 12 and 16 cm to the teat. At the base of five udder quarters, the cloxacillin concentration was between 0.73 and 2.52 μg/g while the cloxacillin was below the limit of quantification in one udder quarter. In contrast to the front quarters, the decrease of the concentration was not quite clear in rear quarters (figure 2). The cloxacillin concentration was measured between 0.67 and 4.2 μg/g in all tissue samples. Taken together, a tendency to have a quite even good distribution trough the gland tissue was obvious.


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

Kietzmann M, Niedorf F, Gossellin J - BMC Vet. Res. (2010)

Cloxacillin concentration (μg/g tissue) in the glandular tissue of rear quarters of the isolated perfused bovine udder measured at constant vertical distances from the teat base 6 h after the intramammary administration of 600 mg cloxacillin benzathine (Orbenin™ extra dry cow) per quarter. Data are given as box plots from six single experiments. The dotted line shows the MIC90 of 0.5 μg/mL against Staphylococcus aureus.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2959039&req=5

Figure 2: Cloxacillin concentration (μg/g tissue) in the glandular tissue of rear quarters of the isolated perfused bovine udder measured at constant vertical distances from the teat base 6 h after the intramammary administration of 600 mg cloxacillin benzathine (Orbenin™ extra dry cow) per quarter. Data are given as box plots from six single experiments. The dotted line shows the MIC90 of 0.5 μg/mL against Staphylococcus aureus.
Mentions: The concentration of cloxacillin in the glandular tissue of all front quarters measured 6 h after administration tended to decrease with increasing vertical distance from the teat. Figure 1 shows this on a logarithmic scale. The decreasing pattern of the concentration could be explained by the high variation of the measured concentrations in the teat region. Especially in one udder quarter, a very high concentration of cloxacillin was measured near the teat. Starting with 4.1 μg/g near the teat (median), the concentration declined to 2.8, 2, 4 and 1.7 μg/g at distances of 8, 12 and 16 cm to the teat. At the base of five udder quarters, the cloxacillin concentration was between 0.73 and 2.52 μg/g while the cloxacillin was below the limit of quantification in one udder quarter. In contrast to the front quarters, the decrease of the concentration was not quite clear in rear quarters (figure 2). The cloxacillin concentration was measured between 0.67 and 4.2 μg/g in all tissue samples. Taken together, a tendency to have a quite even good distribution trough the gland tissue was obvious.

Bottom Line: The 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.After 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.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute for Pharmacology, Toxicology, and Pharmacy, School of Veterinary Medicine, Hannover, Germany. manfred.kietzmann@tiho-hannover.de

ABSTRACT

Background: Various 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.

Methods: Mammary 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.

Results: The 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.

Conclusion: After 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.

Show MeSH
Related in: MedlinePlus