Ye Zhengqi, Gao Hong
Drug Metabolism & Pharmacokinetics, Vertex Pharmaceuticals, Inc. Boston, MA 02210, USA.
Bioanalysis. 2018 Apr 1;10(7):451-459. doi: 10.4155/bio-2017-0288. Epub 2018 Apr 10.
To develop approaches to measure plasma protein binding (PPB) of enzymatically unstable compounds.
Bis-para-nitrophenyl phosphate (BNPP) was used to inhibit enzyme activity and stabilize two model compounds (diltiazem and oseltamivir) that are subject to enzyme-catalyzed hydrolysis in plasma. Protein binding of the compounds in BNPP-treated rat plasma was measured using equilibrium dialysis or ultrafiltration.
PPB measurement of unstable compounds was improved by using enzyme inhibitor to stabilize the compounds in plasma during the assay. The effect of BNPP concentration on drug-protein binding appeared to be compound dependent. Given the compound's nonspecific binding to the assay device can be accounted for in the unbound fraction measurement, ultrafiltration can be a viable alternative or complementary approach for PPB assay of unstable compounds while minimizing the potential impact of enzyme inhibitor on drug-protein binding.
开发测量酶不稳定化合物血浆蛋白结合率（PPB）的方法。
使用双对硝基苯磷酸酯（BNPP）抑制酶活性，并稳定两种在血浆中会发生酶催化水解的模型化合物（地尔硫䓬和奥司他韦）。使用平衡透析或超滤法测量BNPP处理的大鼠血浆中这些化合物的蛋白结合情况。
在测定过程中使用酶抑制剂稳定血浆中的化合物，可改善不稳定化合物的PPB测量。BNPP浓度对药物 - 蛋白结合的影响似乎因化合物而异。鉴于在游离分数测量中可以考虑化合物与测定装置的非特异性结合，超滤法可作为不稳定化合物PPB测定的可行替代方法或补充方法，同时将酶抑制剂对药物 - 蛋白结合的潜在影响降至最低。
