Nickerson B
Hoffmann-La Roche Inc., Nutley, NJ 07110, USA.
J Pharm Biomed Anal. 1997 Apr;15(7):965-71. doi: 10.1016/s0731-7085(96)01922-x.
A capillary electrophoresis (CE) method utilizing indirect ultraviolet (UV) detection was developed for the determination of a non-UV absorbing degradation product, Ro 5-5172, in clidinium bromide drug substance. The electrophoresis buffer consisted of sodium phosphate and benzyltrimethylammonium bromide. Rinsing the capillary with sodium hydroxide followed by water then fresh capillary electrophoresis buffer was found to significantly improve the reproducibility of the migration times of the analytes. To further improve run-to-run reproducibility, an internal marker was used to account for differences in injection volumes and migration times between runs. The precision of the method was found to be less than 1% relative standard deviation for the migration time ratio and peak area ratio of Ro 5-5172 to the internal standard. The method was found to be linear for 0.05-1% Ro 5-5172 with respect to a 10 mg ml-1 sample preparation. The limit of detection was found to be less than 0.01% Ro 5-5172. Results obtained for the analysis of a clidinium bromide drug substance lot using this CE method and a thin layer chromatography method were compared and found to be in agreement.
开发了一种利用间接紫外（UV）检测的毛细管电泳（CE）方法，用于测定溴化氯氮䓬原料药中一种不吸收UV的降解产物Ro 5-5172。电泳缓冲液由磷酸钠和苄基三甲基溴化铵组成。发现先用氢氧化钠冲洗毛细管，再用水冲洗，然后用新鲜的毛细管电泳缓冲液冲洗，可显著提高分析物迁移时间的重现性。为进一步提高批次间的重现性，使用内标来校正不同批次间进样体积和迁移时间的差异。该方法对于Ro 5-5172与内标的迁移时间比和峰面积比，相对标准偏差小于1%。对于10 mg ml-1的样品制备，该方法在0.05 - 1%的Ro 5-5172范围内呈线性。检测限小于0.01%的Ro 5-5172。使用该CE方法和薄层色谱法对一批溴化氯氮䓬原料药进行分析，比较结果发现二者一致。
