The comparison of some pharmacokinetic parameters of sulphadimethoxine estimated by high performance liquid chromatography and three spectrophotometric methods.

The influence of the method used for determination of drugs in biological fluids on the pharmacokinetic parameters of sulphadimethoxine was investigated in healthy adult human subjects. Sulphonamide concentrations were determined by four chemical methods: high performance liquid chromatography (HPLC) and three spectrophotometric techniques, i.e. Bratton-Marshall original method as well as Rieder's modification and author's modification of the Morris technique. The compatibility of pharmacokinetic parameter values calculated from these results was good, the correlation coefficients between HPLC and all spectrophotometric methods were high. It has also been shown that the phenotype of acetylation as well as moderate cigarette smoking which can induce some enzymes responsible for the formation of glucuronide conjugates, i.e. main metabolic pattern for sulphadimethoxine, does not affect the half-time of this drug.