~ 1825 ~ Journal of Entomology and Zoology Studies 2018; 6(3): 1825-1828 E-ISSN: 2320-7078 P-ISSN: 2349-6800 JEZS 2018; 6(3): 1825-1828 © 2018 JEZS Received: 24-03-2018 Accepted: 26-04-2018 M Champawat Department of Pharmacology and Toxicology, College of Veterinary and Animal Science, Rajasthan University of Veterinary and Animal Sciences, Bikaner, Rajasthan, India LN Sankhala Department of Pharmacology and Toxicology, College of Veterinary and Animal Science, Rajasthan University of Veterinary and Animal Sciences, Bikaner, Rajasthan, India P Sharma Department of Pharmacology and Toxicology, College of Veterinary and Animal Science, Rajasthan University of Veterinary and Animal Sciences, Bikaner, Rajasthan, India A Gaur Department of Pharmacology and Toxicology, College of Veterinary and Animal Science, Rajasthan University of Veterinary and Animal Sciences, Bikaner, Rajasthan, India Correspondence LN Sankhala Department of Pharmacology and Toxicology, College of Veterinary and Animal Science, Rajasthan University of Veterinary and Animal Sciences, Bikaner, Rajasthan, India Pharmacokinetic of single dose intramuscular administration of cefquinome using microbiological assay in goats M Champawat, LN Sankhala, P Sharma and A Gaur Abstract The present study was planned to investigate the disposition kinetics of cefquinome at the dose rate of 2 mg kg -1 body weight intramuscularly in healthy marwari male goats at the Livestock Research Station, Kodamdesar, Rajasthan University of Veterinary and Animal Sciences, Bikaner in the month of October, 2016. Plasma concentrations were determined by microbiological assay method using MTCC equivalent (MTCC 1541) of Micrococcus luteus (ATCC 9341) as the test organism. Following intramuscular administration of cefquinome, peak plasma concentration (Cmax) was achieved 5.10 ± 0.51 μg ml -1 at 1 h (tmax). Absorption half-life (t1/2ka), elimination half-life (t1/2β), area under the plasma concentration time curve (AUC) and volume of distribution (Vdarea) were 0.29 ± 0.04 h, 1.48 ± 0.04 h, 14.44 ± 0.82 μg ml -1 h and 0.29 ± 0.02 L kg -1 respectively. In the present study, the plasma levels above the MIC level were maintained up to 6 h following intramuscular administration of cefquinome so as per the general recommendation that T>MIC should be at least 50% of dosage interval for optimum bactericidal effect, a 12 h dosing interval at the rate of 2 mg kg -1 is recommended intramuscularly in goats. Keywords: Bactericidal, plasma concentration, volume of distribution 1. Introduction Cefquinome is a fourth generation aminothiazolyl cephalosporin with broad spectrum of activity against Gram-positive and Gram-negative bacteria, developed exclusively for veterinary use including food animals [15] . It has a broad spectrum of antibacterial activity with time dependent bactericidal effect, as shown by β-lactam antibiotics [19] . It has certain advantages over the preceding cephalosporins: i) it possesses extended spectrum of activity, ii) penetration ability into the periplasmic space of Gram-negative bacteria and enhanced binding with penicillin-binding proteins [5] , iii) stable against chromosomal, iv) and plasmid-encoded β-1 lactamases that are produced by a majority of clinically important bacteria [13] and v) enhanced bioavailability and improved spectrum of antimicrobial activity compared with the second and third-generation cephalosporins [19] . For the sensible use of an antibiotic in rational dosage, the pharmacokinetic investigations are essential. Keeping in view the significant species variation in pharmacokinetic data of antimicrobials, It has been established that the pharmacokinetics data are to be investigated in animal species domesticated in different climate, in which the drug is to be employed clinically [16,7] . Pharmacokinetics studies offer highly relevant information on the time course of the drugs and their metabolites and facilitate the computation of optimal dosage regimens of drugs to maintain their therapeutic concentration at the biophase [21] . So the current study was planned to determine pharmacokinetic profile of cefquinome in goat following single intramuscular injection by employing microbiological assay method in order to establish adequate dose regimen for potential clinical use in goats diseases caused by susceptible microorganisms. 2. Material and Methods 2.1. Experimental Animals The study was conducted on five apparently healthy Marwari male goats (8- 10 month of age, weight between 25-30 kilograms) at the Livestock Research Station, Kodamdesar, Rajasthan University of Veterinary and Animal Sciences, Bikaner in the month of October, 2016. During the study period they were subjected to clinical examination in order to exclude the possibility of any disease. The animals were housed in separate pens and maintained on concentrate,