RESUMO
An NMR procedure is described for the analysis of amyl nitrite as a drug entity and in inhalant dosage forms. The choices of solvent (carbon tetrachloride) and internal standards (biphenyl or benzyl benzoate) were made with respect to stability problems and the presence of stabilizers in the formulation. The method is precise, with a standard deviation of +/-0.5. The NMR results of synthetic solutions and commercial preparations were compared with those obtained by a published relative NMR procedure and a compendial titrimetric method. The results were generally satisfactory.
Assuntos
Nitrito de Amila/análise , Estabilidade de Medicamentos , Espectroscopia de Ressonância MagnéticaAssuntos
Amantadina/análise , Espectroscopia de Ressonância Magnética , Cápsulas/análise , Deutério , Gelatina , Métodos , SolventesRESUMO
An NMR procedure is described by which theophylline and ethylenediamine are simultaneously determined in aminophylline tablets. t-Butyl alcohol was chosen as the internal standard and 4% ammonia-0.3% potassium cyanide in deuterium oxide was the solvent. The solvent system was selected to deal with the problems of solubility of the theophylline, overlapping of the components' resonance signals, and potential interference from metal impurities. Known standard and commercial preparations were determined and the results compared with those obtained by alternative procedures. The technique, when applied to the determination of aminophylline in tablets, is rapid, simple and specific and has an error of 1-2%.
