Wu S M, Ho Y H, Wu H L, Chen S H, Ko H S
School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Taiwan.
Electrophoresis. 2001 Aug;22(13):2717-22. doi: 10.1002/1522-2683(200108)22:13<2717::AID-ELPS2717>3.0.CO;2-2.
In this study, low concentrations of histamine2-receptor (H2-)antagonists were effected across a water plug, with separation taking place in a binary buffer comprising ethylene glycol and NaH2PO4 (pH 5.0), and detection at 214 nm. Liquid-liquid extraction with ethyl acetate- isopropanol is shown to provide extracts that are sufficiently clean. The calibration curves were linear over a concentration range of 0.1-2.00 microg/mL cimetidine, 0.2-5.0 microg/mL ranitidine-HCl, 0.3-5.0 microg/mL nizatidine, and 0.1-3.0 microg/mL famotidine. Mean recoveries were > 82%, while the intra- and interday relative standard deviations (RSDs) and relative errors (REs) were all < 13%. The method is sensitive with a detection limit of 3 ng/mL cimetidine, 30 ng/mL ranitidine HCl, 50 ng/mL nizatidine and 10 ng/mL famotidine (S/N = 3, electric-driven injection 90 s). This newly developed capillary electrophoresis (CE) method was applied for the determination of analytes extracted from plasma taken from a volunteer dosing a cimetidine, ranitidine, and nizatidine tablet simultaneously. These three H2-antagonists can be detected in real samples by this method, excluding the low dosing of famotidine tablet.
在本研究中，低浓度的组胺2受体（H2-）拮抗剂通过水塞进行作用，分离在由乙二醇和磷酸二氢钠（pH 5.0）组成的二元缓冲液中进行，并在214 nm处检测。结果表明，用乙酸乙酯 - 异丙醇进行液 - 液萃取可提供足够纯净的提取物。西咪替丁浓度范围为0.1 - 2.00μg/mL、雷尼替丁 - HCl浓度范围为0.2 - 5.0μg/mL、尼扎替丁浓度范围为0.3 - 5.0μg/mL、法莫替丁浓度范围为0.1 - 3.0μg/mL时，校准曲线呈线性。平均回收率>82%，日内和日间相对标准偏差（RSD）以及相对误差（RE）均<13%。该方法灵敏度高，西咪替丁的检测限为3 ng/mL、雷尼替丁HCl为30 ng/mL、尼扎替丁为50 ng/mL、法莫替丁为10 ng/mL（S/N = 3，电动进样90 s）。这种新开发的毛细管电泳（CE）方法用于测定从同时服用西咪替丁、雷尼替丁和尼扎替丁片剂的志愿者血浆中提取的分析物。通过该方法可在实际样品中检测到这三种H2拮抗剂，但不包括低剂量的法莫替丁片剂。
