title: Determination of cloxacillin residues in dairy cows after intramammary administration.
abstract: The aim of this study was to perform a comparative analysis of the characteristics of cloxacillin (CLO) (MRL of withdrawal in bovine milk is 30 ng/g) after a single intramammary (IMM) dose in the dry period (DP) and lactation (LP), and to establish a high-performance liquid chromatography (HPLC) analytical method for CLO detection in milk. The research was conducted on a group of 10 cows in DP and 10 in LP. A single dose of 600 mg of CLO was administrated by the IMM route for a single quarter in DP and 500 mg for a single quarter in LP. CLO concentration was analyzed by HPLC. CLO was monitored at a wavelength of 206 nm. Pharmacokinetic calculations were performed using Phoenix®WinNonlin®6.4 software. The calibration curve was linear over the range of 13.03-28 019.00 ng/g with the coefficient of determination R2> 0.999. CLO withdrawal in both the LP and DP group had a biphasic nature. The total CLO elimination in the DP and LP group was reached after 36 and 6.5 days, respectively. A quantitative and confirmatory method for the determination of CLO in fresh milk has been established. We have confirmed that the withdrawal of CLO in the DP group is not a linear process and has a stepwise character.
authors.affiliation: Department of Pharmacology, Faculty of Veterinary Medicine, University of Life Sciences, Lublin, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Burmańczuk
authors.affiliation: Polpharma Biologics, Gdańsk, Poland.
authors.forename: T
authors.initials: T
authors.lastname: Grabowski
authors.affiliation: Department of Pharmacology, Faculty of Veterinary Medicine, University of Life Sciences, Lublin, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Osypiuk
authors.affiliation: Department of Pharmacology, Faculty of Veterinary Medicine, University of Life Sciences, Lublin, Poland.
authors.forename: B
authors.initials: B
authors.lastname: Polska
authors.affiliation: Department of Pharmacology, Faculty of Veterinary Medicine, University of Life Sciences, Lublin, Poland.
authors.forename: C
authors.initials: C
authors.lastname: Kowalski
mesh_terms: D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D003023:Cloxacillin / Q000493:pharmacokinetics*; D005260:Female; D005506:Food Contamination / Q000032:analysis*; D007774:Lactation; D008414:Mastitis, Bovine / Q000188:drug therapy* / Q000378:metabolism*; D008892:Milk / Q000737:chemistry*
chemical_list: D003023:Cloxacillin