Some pharmacokinetic parameters of ampicillin/sulbactam combination after intravenous and intramuscular administration to goats

Summary

Some pharmacokinetic parameters of an ampicillin/sulbactam (2:1) combination were studied in six goats, after intravenous and intramuscular injection at a single dosage of 20 mg/kg bodyweight (13.33 mg/kg of sodium ampicillin and 6.67 mg/kg of sodium sulbactam). The drugs were distributed according to an open two‐compartment model. The apparent volumes of distribution calculated by the area method of ampicillin and sulbactam were 0.34 ± 0.04 l/kg and 0.45 ± 0.15 1/kg, respectively, and the total body clearances were 0.72 ± 0.11 and 0.38 ± 0.07 l/kg.h. The half‐lives of ampicillin after intravenous and intramuscular administration were 0.32 ± 0.04 h and 0.71 ± 0.14 h, respectively. For sulbactam the half‐lives were 0.79 ± 0.18 h and 1.13 ± 0.21 h after administration by the same routes. The bioavailability after intramuscular injection was high and similar for both drugs (98,29% for ampicillin and 101.84% for sulbactam). The mean peak plasma levels of ampicillin (0.43 ± 0.27 h) and sulbactam (0.34 ± 0.14 h) were reached at a similar time, and peak concentrations were also similar and non‐proportional to the dose of the products administered (11.02 ± 3.11 mg/l of ampicillin and 9.5 ± 0.98 mg/l of sulbactam).