Pharmacokinetics and improved bioavailability of toltrazuril after oral administration to rabbits

Review of triazine antiprotozoal drugs used in veterinary medicine

“…Following oral administration of 10 mg/kg in pigs, toltrazuril is well absorbed, reaching maximum concentrations ~15 hr postadministration . In rabbits, toltrazuril is well absorbed following oral administration, resulting in a prolonged elimination half-life (T 1/2 ) of 20 hr and achieving concentrations associated with other reports of clinical efficacy (Hu, Liu, Shang, Yang, & Yang, 2010). The pharmacokinetic parameters of toltrazuril in different species are shown in Table 1.…”

The hydroxypropyl–β-cyclodextrin complexation of toltrazuril for enhancing bioavailability

“…In this study, the pharmacokinetics of Tol after oral administration of Tol or Tol-HP-β-CD in both groups was best described by a double-compartment model, which was similar to previous findings. 4 , 34 The absorption of chemicals from the GI tract depends on the physiochemical properties of compounds, such as lipid solubility and dissociation rate. Although an increase in lipid solubility generally increases the absorption of chemicals, extremely lipid-soluble chemicals may have poor oral bioavailability because highly lipophilic molecules can become stuck in the lipid portion of the plasma membrane, 35 whereas highly lipophilic compounds are more difficult to dissolve in GI fluids.…”

Gastrointestinal Disease in Exotic Small Mammals

“…Numerous therapeutic agents have been used as preventatives and treatments for rabbit intestinal and hepatic coccidiosis, including amprolium (amprolium 9.6% in drinking water 0.5 mL per 500 mL), 76 sulfadimethoxine (15 mg/kg orally, twice a day for 10 days), 41,73 trimethoprimsulfamethoxazole (30 mg/kg orally, twice a day for 10 days), 41 and toltrazuril (10 mg/kg orally). 77,78 A recent research investigation revealed that a single oral dose of 2.5 mg/kg or 5.0 mg/kg toltrazuril, or a single oral dose of 50 mg/kg sulfadimethoxine followed by placement in drinking water at 1 g/4 L water for 9 days, were found to significantly reduce the fecal oocyst count in rabbits by 73% to 99%. 75 The results of the study also reported that the extent of fecal oocyst reduction was not dependent on the dose of toltrazuril.…”