Bioavailability and pharmacokinetics of sulfamethazine in the pony

Abstract

Sulfamethazine has been used in therapy of equine disease for over 40 years (Welsh et al, 1946). Although sulfamethazine appears to be well absorbed when fed mixed with grain and is reported to reach its peak concentration 8 h after administration, its oral bioavailability and pharmacokinetics have not been reported (Schroeder et al., 1948; Meier et al, 1980). The purpose of the present study was to determine the major pharmacokinetic values and the oral bioavailability of sulfamethazine at a dosage predicted to produce therapeutic blood concentrations in the pony.