El Ragehy N A, Badawey A M, Khateeb S Z-El
Department of Analytical Chemistry, Faculty of Pharmacy, Cairo University, Kasr Elini Street, Cairo, Egypt.
J Pharm Biomed Anal. 2002 Jun 15;28(6):1041-53. doi: 10.1016/s0731-7085(01)00664-1.
Four stability-indicating procedures have been suggested for determination of the non sedating antihistaminic agent loratadine. Loratadine being an ester undergoes alkaline hydrolysis and the corresponding acid derivative is produced as a degradation product. Its identity was confirmed using IR and MS. The first procedure is based on determination of loratadine by HPLC with detection at wavelength, 250 nm. Mobile phase is acetonitrile:orthophosphoric acid (35:65) using benzophenone as an internal standard. Sensitivity range is 5.00-50.00 microg/ml. Second determination is a densitometric procedure based on determination of loratadine in the presence of its degradate at lambda 246 nm using the mobile phase; methanol:ammonia (10:0.15). Sensitivity range is 1.25-7.50 microg per spot. The third procedure is a spectrophotometric one where a mixture of loratadine and its degradate are resolved by first derivative ratio spectra. Sensitivity range is found to be 3.00-22.00 microg/ml, upon carrying out the measurements at wavelengths 236, 262.4 and 293.2 nm. The fourth procedure is based on second derivative spectrophotometry, where D(2) measurements are carried out at lambda 266 nm. The sensitivity range is 3.00-22.00 microg/ml. The validity of the described procedures was assessed by applying the standard addition technique. Statistical analysis of the results have been carried out revealing high accuracy and good precision. The suggested procedures could be used for determination of loratadine both in pure and dosage forms, as well as in the presence of its degradate.
已提出四种稳定性指示方法用于测定非镇静性抗组胺药氯雷他定。氯雷他定作为酯会发生碱性水解，相应的酸衍生物作为降解产物生成。通过红外光谱（IR）和质谱（MS）确认了其结构。第一种方法基于高效液相色谱法（HPLC）测定氯雷他定，检测波长为250nm。流动相为乙腈：正磷酸（35:65），使用二苯甲酮作为内标。检测范围为5.00 - 50.00μg/ml。第二种测定方法是密度测定法，基于在λ246nm处，使用流动相甲醇：氨水（10:0.15），在其降解产物存在的情况下测定氯雷他定。检测范围为每点1.25 - 7.50μg。第三种方法是分光光度法，其中氯雷他定及其降解产物的混合物通过一阶导数比率光谱法进行分离。在波长236、262.4和293.2nm处进行测量时，检测范围为3.00 - 22.00μg/ml。第四种方法基于二阶导数分光光度法，在λ266nm处进行D(2)测量。检测范围为3.00 - 22.00μg/ml。通过标准加入技术评估了所描述方法的有效性。对结果进行了统计分析，显示出高准确度和良好的精密度。所建议的方法可用于测定纯品和剂型中的氯雷他定，以及在其降解产物存在的情况下进行测定。
