Disposition of sulfonamides in food-producing animals IV: Pharmacokinetics of sulfamethazine in cattle following administration of an intravenous dose and three oral dosage forms

✍ Scribed by Richard F. Bevill; Lewis W. Dittert; David W. A. Bourne

• Publisher: John Wiley and Sons
• Year: 1977
• Tongue: English
• Weight: 566 KB
• Volume: 66
• Category: Article
• ISSN: 0022-3549
• DOI: 10.1002/jps.2600660503

✦ Synopsis

The plasma and urine data obtained following intravenous administration of sulfamethazine to cattle were fit to a one-compartment pharmacokinetic model with a half-life of elimination of 9 hr and a volume of distribution of 0.35 liter/kg. Sulfamethazine was eliminated by excretion of unchanged sulfamethazine (18%) into urine and by formation of three metabolites subsequently excreted into urine. Sulfamethazine also was administered as a solution, a rapid-release bolus, and a sustained-release bolus. The change in the urinary metabolic pattern with different routes of administration suggested that first-pass metabolism was occurring during the absorption process. The absorption half-life was 6 hr. The absorption process for the two solid boluses kinetically appeared to include a dissolution step.