[Study of serum concentrations and urinary excretion of secnidazole after oral administration in man. Comparison with tinidazole]. / Etude des taux sériques et de l'élimination urinaire du secnidazole après administration orale chez l'homme. Comparaison avec le tinidazole.

Secnidazole, a derivative of 5-nitro imidazole exhibits trichomonacid, amoebicid and antimicrobial properties; it has been studied in view of its biological fate in healthy volunteers (man and woman) comparatively with tinidazole. Both products were administered orally to the same volunteers at the single dose level of 2 g. The seric concentrations and the pharmacokinetic profile were determined up to the 72nd hour after drug administration. The whole urinary excretion (unchanged product + metabolites) during the same period was determined in percent of the administered dose level. Secnidazole is particularly different from tinidazole owing to its slower blood clearance. The apparent average half-life in the ten volunteers (5 men and 5 women) is about 17 hours for secnidazole and 13 hours for tinidazole. However, for both drugs, a difference between men and women was demonstrated: in female volunteers, the decrease in blood concentrations occurs a little quicker than in male volunteers. Regarding urinary excretion, it is also a little greater in female volunteers than in male volunteers.

Determination of nofedone in human serum by electron-capture GLC.

An electron-capture GLC method to measure nofedone in human serum was developed. A homolog of nofedone was added to the serum as an internal standard before the sample was alkalinized with pH 9.5 phosphate buffer and extracted with ethylene dichloride containing 0.5% isopentyl alcohol. This organic phase was extracted with 0.2N HCl, the acidic aqueous phase was neutralized immediately, and the extraction with ethylene dichloride was repeated. The ethylene dichloride phase was evaporated to dryness, and the residue was reacted with heptafluorobutyric anhydride. The derivatives were chromatographed at 290 degrees on a 1% Dexsil 300 column. Data on apparent recovery, accuracy, and specificity are given. The detection limit was 5 ng/ml of serum. Serum levels over time in one patient after intravenous administration of 1 mg/kg and after oral administration of 50, 100, and 150 mg of nofedone are presented.