Application of nuclear magnetic resonance spectroscopy for quantitative analysis of miconazole, metronidazole and sulfamethoxazole in pharmaceutical and urine samples.

Specific, accurate and precise NMR methods were developed for determining miconazole, metronidazole and sulfamethoxazole antibiotic drugs in authentic, pharmaceutical and urine samples. Proton nuclear magnetic resonance spectroscopy (1H NMR) with maleic acid as an internal standard and DMSO-d6 as NMR solvent were used. 1H NMR signals at 9.0, 8.06, 7.50 and 6.26 ppm corresponding to miconazole, metronidazole, sulfamethoxazole and maleic acid were respectively used for calculating the concentrations of drugs per unit dose. Average percent recoveries of (97.54-101.10), (98.06-100.46) and (97.83-102.83) with average uncertainties of 1.02, 0.45 and 0.86 were respectively obtained for determining authentic samples of miconazole, metronidazole and sulfamethoxazole in the concentration range of 0.92-170 mg/0.6 ml DMSO-d6. In pharmaceutical formulations and urine samples, average percent recoveries in the ranges of 97.50-101.33 and 94.46-100.86 were respectively obtained. Relative standard deviations (R.S.D.)

Quantitative determinations of levofloxacin and rifampicin in pharmaceutical and urine samples using nuclear magnetic resonance spectroscopy.

Rapid, specific and simple methods for determining levofloxacin and rifampicin antibiotic drugs in pharmaceutical and human urine samples were developed. The methods are based on (1)H NMR spectroscopy using maleic acid as an internal standard and DMSO-d6 as NMR solvent. Integration of NMR signals at 8.9 and 8.2 ppm were, respectively, used for calculating the concentration of levofloxacin and rifampicin drugs per unit dose. Maleic acid signal at 6.2 ppm was used as the reference signal. Recoveries of (97.0-99.4)+/-0.5 and (98.3-99.7)+/-1.08% were obtained for pure levofloxacin and rifampicin, respectively. Corresponding recoveries of 98.5-100.3 and 96.8-100.0 were, respectively, obtained in pharmaceutical capsules and urine samples. Relative standard deviations (R.S.D.) values < or =2.7 were obtained for analyzed drugs in pure, pharmaceutical and urine samples. Statistical Student's t-test gave t-values < or =2.87 indicating insignificant difference between the real and the experimental values at the 95% confidence level. F-test revealed insignificant difference in precisions between the developed NMR methods and each of fluorimetric and HPLC methods for analyzing levofloxacin and rifampicin.