Parimoo P, Prasad C V, Vineeth R
Department of Pharmacy, Birla Institute of Technology and Science, Rajasthan, India.
J Pharm Biomed Anal. 1996 Feb;14(4):389-93. doi: 10.1016/0731-7085(95)01659-7.
A difference spectrophotometric procedure has been developed for simultaneous determination of metronidazole (MDZ) and nalidixic acid (NA) in tablets. The method comprised the measurement of the absorbance of a solution of the tablet extract in 0.1 M NaOH relative to that of an equimolar solution in 0.1 M HCl at 292 nm for NA and 325 nm for MDZ. The presence of identical isosbestic points for pure drug solutions and tablet extracts indicated the non-interference of excipients in the absorption at these wavelengths. Compliance with Beer's law was observed in the concentration ranges 5-25 micrograms ml(-1) for MDZ and 15-35 micrograms ml(-1) for NA these wavelengths.
已开发出一种差示分光光度法，用于同时测定片剂中的甲硝唑（MDZ）和萘啶酸（NA）。该方法包括测量片剂提取物在0.1 M NaOH溶液中的吸光度，并与在0.1 M HCl中的等摩尔溶液在292 nm（用于NA）和325 nm（用于MDZ）处的吸光度进行比较。纯药物溶液和片剂提取物存在相同的等吸收点，表明辅料在这些波长下对吸收无干扰。在这些波长下，MDZ的浓度范围为5 - 25微克/毫升，NA的浓度范围为15 - 35微克/毫升时，符合比尔定律。
