Pharmacokinetics and bioavailability of imidocarb dipropionate in swine

A two-way crossover study was performed in eight healthy young pigs to determine the pharmacokinetics of imidocarb dipropionate (IMDP) following intravenous (2 mg/kg b.w.) and intramuscular (2 mg/kg b.w.) administrations. Each animal received one intravenous and one intramuscular injection with a 30-day washout period between the two-treatments. Plasma concentrations were measured by high-performance liquid chromatography (HPLC) assay with UV detector at regular intervals for up to 24 h post-injection. Intravenous plasma concentration profiles best fit a three-compartmental model yielding a mean system clearance (Cl((s))) of 558 mL/kg.h and a mean half-life of 13.91 h. Mean imidocarb AUC((0-infinity)) (microg.h/mL), V(c) (L/kg), V(d(area))(L/kg) and MRT((0-t)) (h) values were 3.58, 0.11, 14.36 and 1.46, respectively. Compartmental modeling of imidocarb, after intramuscular administration produced best fit for two-compartmental model yielding mean Kalpha (h(-1)), Cmax (microg/mL), tmax (h), and bioavailability (%) of 3.89, 2.02, 0.54, and 86.57 for the 2 mg/kg dose level. The present studies showed that IMDP was rapidly absorbed, widely distributed, and slowly eliminated. No adverse effects were observed in any of the pigs after i.v. and i.m. administrations of IMDP. The favorable PK behavior, such as the long half-life, acceptable bioavailability indicated that it is likely to be effective in pigs.