Pindrus Mariya A, Shire Steven J, Yadav Sandeep, Kalonia Devendra S
Department of Pharmaceutical Sciences, University of Connecticut, U-3092, Storrs, Connecticut, 06269, USA.
Late Stage Pharmaceutical Development, Genentech, Inc., 1 DNA Way, South San Francisco, California, 94080, USA.
Pharm Res. 2017 Apr;34(4):836-846. doi: 10.1007/s11095-017-2112-8. Epub 2017 Feb 2.
To determine the intrinsic viscosity of several monoclonal antibodies (mAbs) under varying pH and ionic strength solution conditions.
An online viscosity detector attached to HPLC (Viscotek®) was used to determine the intrinsic viscosity of mAbs. The Ross and Minton equation was used for viscosity prediction at high protein concentrations. Bulk viscosity was determined by a Cambridge viscometer.
At 15 mM ionic strength, intrinsic viscosity of the mAbs determined by the single-point approach varied from 5.6 to 6.4 mL/g with changes in pH. High ionic strength did not significantly alter intrinsic viscosity, while a significant increase (up to 24.0 mL/g) was observed near zero mM. No difference in bulk viscosity of mAb3 was observed around pH 6 as a function of ionic strength. Data analysis revealed that near zero mM ionic strength limitations of the single-point technique result in erroneously high intrinsic viscosity.
Intrinsic viscosity is a valuable tool that can be used to model baseline viscosity at higher protein concentrations. However, it is not predictive of solution non-ideality at higher protein concentrations. Furthermore, breakdown of numerous assumptions limits the applicability of experimental techniques near zero mM ionic strength conditions. For molecules and conditions studied, the single-point approach produced reliable intrinsic viscosity results at 15 mM. However, this approach must be used with caution near zero mM ionic strength. Data analysis can be used to reveal whether determined intrinsic viscosity is reliable or erroneously high.
确定几种单克隆抗体（mAb）在不同pH值和离子强度溶液条件下的特性黏度。
使用连接到高效液相色谱仪（Viscotek®）的在线黏度检测器来测定单克隆抗体的特性黏度。Ross和Minton方程用于预测高蛋白浓度下的黏度。用剑桥黏度计测定本体黏度。
在15 mM离子强度下，通过单点法测定的单克隆抗体的特性黏度随pH值变化在5.6至6.4 mL/g之间。高离子强度不会显著改变特性黏度，而在接近零mM时观察到显著增加（高达24.0 mL/g）。在pH 6附近，未观察到mAb3的本体黏度随离子强度的变化。数据分析表明，在接近零mM离子强度时，单点技术的局限性会导致特性黏度错误地偏高。
特性黏度是一种有价值的工具，可用于模拟高蛋白浓度下的基线黏度。然而，它不能预测高蛋白浓度下溶液的非理想性。此外，众多假设的失效限制了在接近零mM离子强度条件下实验技术的适用性。对于所研究的分子和条件，单点法在15 mM时产生了可靠的特性黏度结果。然而，在接近零mM离子强度时必须谨慎使用这种方法。数据分析可用于揭示所测定的特性黏度是可靠的还是错误地偏高。
