Benetton S A, Kedor-Hackmann E R, Santoro M I, Borges V M
Departamento de Farmácia, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Caixa Postal 66355, CEP 05389-970, São Paulo, Brazil.
Talanta. 1998 Nov;47(3):639-43. doi: 10.1016/s0039-9140(98)00111-8.
Two methods are described for the determination of rifampicin and isoniazid in mixtures by visible spectrophotometry and first-derivative ultraviolet spectrophotometry. The absorbance at 475 nm in buffer solution pH 7.4 was employed to determine rifampicin after applying the three-point correction technique between 420 and 520 nm, while the amplitude of the first-derivative spectrophotometric spectrum at 257 nm in HCl 0.012 M was selected for the determination of isoniazid. The methods are rapid, simple and do not require any separation step. The recovery average was 99.03% for rifampicin and 100.01% for isoniazid. The methods were applied to determine the two compounds in commercial capsules and compared with the official method of the USP XXIII with good agreement between the results.
介绍了两种通过可见分光光度法和一阶导数紫外分光光度法测定混合物中利福平与异烟肼的方法。在pH 7.4缓冲溶液中，于420至520 nm应用三点校正技术后，利用475 nm处的吸光度测定利福平；而在0.012 M盐酸中，选择257 nm处一阶导数分光光度光谱的振幅来测定异烟肼。这些方法快速、简便，且无需任何分离步骤。利福平的平均回收率为99.03%，异烟肼的平均回收率为100.01%。将这些方法应用于测定市售胶囊中的这两种化合物，并与美国药典XXIII的法定方法进行比较，结果之间具有良好的一致性。
