Determination of total and free amitriptyline and nortriptyline in human plasma by RP-HPLC
- VernacularTitle:反相高效液相色谱法测定血浆中阿米替林及其代谢物去甲替林的总浓度和游离浓度
- Author:
Jinheng LI
;
Jinqiu XU
;
Xiaomei CAO
;
Dongyang CHEN
- Publication Type:Journal Article
- From:
Chinese Pharmacological Bulletin
2001;17(1):104-107
- CountryChina
- Language:Chinese
-
Abstract:
AIM To develop a sensitive, specific and reliable reversed-phase high performance liquid chromatographic method(RP-HPLC) to determine the total and unbound(free) concentrations in human plasma of amitriptyline and its major metabolite, nortriptyline. METHODS The assay involved a simple extraction procedure. The mobile phase consisted of acetonitrile and distilled water(30∶70, V/V), containing triethylamine(0.5%) and orthophosphoric acid(0.3%), pH 3.1. Separation was achieved on the C18 ODS column and the effluent was measured for UV absorption at 240 nm. RESULTS The calibration curves were linear in the range of 4～400 μg*L-1 for total concentration, and in the range of 4～64 μg*L-1 for free concentration for both amitriptyline and nortriptyline. The lowest limits of detection were 4 μg*L-1 for both compounds. The absolute recovery rates were 102.0%±3.77% for amitriptyline and 99.3%±7.13% for nortriptyline. The precision values(RSD) of intra-day and inter-day for both amitriptyline and for nortriptyline were determined to be <5%, and <8%, respectively. The method was applied to determine the total and free concentrations in plasma of the healthy volunteers after a single oral dose of 50 mg amitriptyline. CONCLUSION The assay was simple, repid, highly selective and sensitive. It is suitable for the routine analysis of total and free drug concentrations in plasma using readily available instruments with lower cost.
