Sved S, McGilveray I J, Beaudoin N
Biopharm Drug Dispos. 1981 Apr-Jun;2(2):177-84. doi: 10.1002/bdd.2510020210.
A sensitive and specific method for the estimation of theophylline-7-acetic acid in plasma by high performance liquid chromatography is described. Acidified plasma is extracted with chloroform-n-butanol (85: 15), back extracted with phosphate buffer (0.5 mmol-1, pH 6.5), and finally the acidified aqueous phase extracted again with chloroform-butanol. After evaporation of the extract the residue is redissolved in the chromatographic mobile phase (hexane-dichloromethane-ethanol-acetic acid, 10 : 86 : 3 : 1) and chromatographed on silica gel. The method was used to follow the plasma theophylline-7-acetic acid concentrations in two volunteers after single oral doses of 1.0 g of the drug. The results confirm previous reports, based on urine data and on plasma data following intravenous administration, that the drug is poorly absorbed (apparent bioavailability of 1 and 2 per cent), rapidly eliminated (half-life of 1.0 and 2.4 h) and not converted to theophylline.
本文描述了一种通过高效液相色谱法测定血浆中茶碱 - 7 - 乙酸的灵敏且特异的方法。酸化后的血浆用氯仿 - 正丁醇（85 : 15）萃取，再用磷酸盐缓冲液（0.5 mmol/L，pH 6.5）反萃取，最后酸化的水相再次用氯仿 - 丁醇萃取。萃取液蒸发后，残留物重新溶解于色谱流动相（己烷 - 二氯甲烷 - 乙醇 - 乙酸，10 : 86 : 3 : 1）中，并在硅胶上进行色谱分析。该方法用于跟踪两名志愿者单次口服1.0 g该药物后血浆中茶碱 - 7 - 乙酸的浓度。结果证实了先前基于尿液数据和静脉给药后血浆数据的报道，即该药物吸收较差（表观生物利用度为1%和2%），消除迅速（半衰期为1.0小时和2.4小时）且未转化为茶碱。
