Revista de Bioanálise e Biomedicina

Effect of Induced Mastitis on Disposition Kinetics of Gatifloxacin Following Intravenous Administration in Goats

Abstract

Vishakha Singh, Mahendra Ram, Birendra Kumar Roy and Kaushal Kumar Singh

Disposition kinetic studies of gatifl oxacin (GAT) was conducted after single i.v. dose (10 mg/kg) in six healthy and six mastitic Black Bengal lactating goats. Mastitis was induced by coagulase positive S. aureus. The concentration of the drug was estimated by HPLC. The maximum milk concentration was found to be signifi cantly (p< 0.05) higher in mastitic goats (12.78 ± 3.11 μg/ml) than healthy (9.17 ± 1.41 μg/ml). The therapeutic milk concentration in mastitic goats (0.13 ± 0.05 to 12.41 ± 2.99 μg/ml) was maintained for 48 h which was signifi cantly (p<0.01) longer than in healthy goats (24 h). The elimination half-life in plasma and milk of mastitic goats (5.82 ± 0.67 and 8.20±0.21 h) was signifi cantly (p<0.01) higher than healthy (4.54 ± 0.75 and 3.67±0.09 h).It indicates that GAT persisted in the body of mastitic goats for a longer duration. The AUC_milk/AUC_plasma ratio was 5.82. The t½ milk /t½ plasma ratio was 1.41. MIC in this experiment was considered to be 0.1 μg/ml. The AUC/MIC ratio of plasma and milk of mastitic goats were 180 and 1049 respectively. On the basis of the results obtained it was concluded that GAT exhibited improved pharmacokinetic parameters with good penetration and longer persistence in mastitic milk, which will be of great help in the treatment of mastitis in goats caused by S. aureus.