Pharmacokinetics and distribution of ceftazidime to milk after intravenous and intramuscular administration to lactating female dromedary camels (Camelus dromedarius)

Abstract

To determine the plasma disposition kinetics, absolute bioavailability, and milk concentrations of ceftazidime in healthy lactating female dromedary camels (Camelus dromedarius) following IV and IM administration of a single dose of 10 mg/kg (4.5 mg/lb). Prospective crossover study. 8 healthy adult lactating female dromedary camels. Camels received ceftazidime (10 mg/kg) IV and IM in a crossover study design with a 15-day washout period between treatments. Plasma and milk samples were collected at predetermined times for 48 hours after drug administration and analyzed by use of high-performance liquid chromatography. A 2-compartment open model best represented the plasma concentration-versus-time data after IV and IM administration of ceftazidime to camels. Plasma ceftazidime concentrations decreased biexponentially after IV administration with mean distribution and elimination half-lives of 0.3 hours and 2.85 hours, respectively. After IM administration, the mean maximum plasma concentration of ceftazidime was 32.43 μg/mL (1.21 hours after administration), mean elimination half-life was 3.20 hours, mean residence time was 4.84 hours, and mean systemic bioavailability was 93.72%. Distribution of ceftazidime from plasma to milk was rapid and extensive as indicated by the ratio of the area under the milk concentration-versus-time curve to the area under the plasma concentration-versus-time curve and the ratio of the maximum milk concentration to the maximum plasma concentration of ceftazidime after IV and IM administration. Results suggested that ceftazidime may be a useful treatment for female camels with mastitis caused by susceptible microorganisms.