La Rosa C, Mather L E, Morgan D J
Br J Clin Pharmacol. 1984 Apr;17(4):411-5. doi: 10.1111/j.1365-2125.1984.tb02365.x.
Several methodological variables potentially influencing the plasma protein binding of [14C]-pethidine in vitro were investigated using equilibrium dialysis and rigorous pH control. Ionic strength of buffer, pethidine concentration and 21 days of plasma samples frozen to -8 degrees C did not affect the outcome of the binding experiments. Unbound fraction decreased with increasing temperatures between 25 degrees C and 37 degrees C. Unbound fraction decreased with increased pH between pH 7.0 and 8.0; the mean unbound fraction at an equilibrium pH of 7.4 and at 37 degrees C was 0.58 (s.d. 0.03, n = 58). It is likely that previous reports of pethidine unbound fraction as being between 0.2 and 0.4 represent artefacts caused by inadequate pH control during dialysis.
使用平衡透析法并严格控制pH值，研究了几个可能在体外影响[14C] - 哌替啶血浆蛋白结合的方法学变量。缓冲液的离子强度、哌替啶浓度以及冷冻至 -8℃ 保存21天的血浆样本均不影响结合实验结果。在25℃至37℃之间，未结合分数随温度升高而降低。在pH 7.0至8.0之间，未结合分数随pH升高而降低；在平衡pH值为7.4且温度为37℃时，平均未结合分数为0.58（标准差0.03，n = 58）。先前报道的哌替啶未结合分数在0.2至0.4之间，很可能是透析过程中pH控制不当导致的假象。
