Belal F, Al-Shaboury S, Al-Tamrah A S
Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, 11451, Riyadh, Saudi Arabia.
J Pharm Biomed Anal. 2002 Nov 7;30(4):1191-6. doi: 10.1016/s0731-7085(02)00471-5.
A simple, sensitive and specific spectrofluorimetric method has been developed for the determination of labetalol (LBT). The method is based on the reaction between LBT and ethylacetoacetate in the presence of sulphuric acid to give yellow fluorescent product with excitation wavelength of 312 nm and emission wavelength of 432 nm. The reaction conditions were studied and optimized. The fluorescence intensity-concentration plot is rectilinear over the range 1-15 microgram/ml with minimum detectability limit of 0.8 microgram/ml (2.16 x 10(-6) M). The proposed method was successfully applied to commercial tablets containing LBT, the percentage recoveries agreed well with those obtained using the official methods. Hydrochlorothiazide, which is frequently co-formulated with LBT did not interfere with the assay. The method was further extended to the in-vitro determination of LBT in spiked human urine samples. The percentage recovery was 101.50+/-6.18 (n=6). A proposal of the reaction pathway was postulated.
已开发出一种简单、灵敏且特异的荧光分光光度法用于测定拉贝洛尔（LBT）。该方法基于LBT与乙酰乙酸乙酯在硫酸存在下发生反应，生成黄色荧光产物，其激发波长为312nm，发射波长为432nm。对反应条件进行了研究和优化。荧光强度 - 浓度曲线在1 - 15微克/毫升范围内呈线性，最低检测限为0.8微克/毫升（2.16×10⁻⁶M）。所提出的方法成功应用于含LBT的市售片剂，回收率与采用官方方法获得的结果吻合良好。常与LBT共同配制的氢氯噻嗪不干扰该测定。该方法进一步扩展至加标人尿样中LBT的体外测定。回收率为101.50±6.18（n = 6）。还推测了反应途径。
