ISOLATION, IDENTIFICATION AND DETERMINATION OF SULFADIAZINE AND ITS HYDROXY METABOLITES AND CONJUGATES FROM MAN AND RHESUS-MONKEY BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

The following metabolites of sulfadiazine (S) were isolated from monke y urine by preparative HPLC: 5-hydroxysulfadiazine (5OH), 4-hydroxysul fadiazine (4OH) and the glucuronide (5OHgluc) and sulfate conjugate of 5OH (5OHsulf). The compounds were identified by NMR, mass and infrare d spectrometry and hydrolysis by beta-glucuronidase. The analysis of S , the hydroxymetabolites (4OH, 5OH) and conjugates N-4-acetylsulfadiaz ine (N-4), 5OHgluc and 5OHsulf in human and monkey plasma and urine sa mples was performed using reversed-phase gradient HPLC with UV detecti on. In plasma, S and N-4 could be detected in high concentrations, whe reas the other metabolites were present in only minute concentrations. In urine, S, the metabolites and conjugates were present. The limit o f quantification of the compounds in plasma varies between 0.2 and 0.6 mu g/ml (S 0.31, N-4 0.40, 4OH 0.20, 5OH 0.37, 5OHgluc 0.33 and 5OHsu lf 0.57 mu g/ml). In urine it varies between 0.6 and 1.1 mu g/ml (S 0. 75, N-4 0.80, 4OH 0.60, 5OH 0.80, 5OHgluc 0.80 and 5OHsulf 1.1 mu g/ml ). The method was applied to studies with healthy human subjects and R hesus monkeys. The metabolites 5OH, 5OHgluc and 5OHsulf were present i n Rhesus monkey and not in man. Preliminary results of studies of meta bolism and pharmacokinetics in Rhesus monkey and man are presented.