Department of Chemical & Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States.
Drug Product Development, Amgen Inc., Thousand Oaks, California 91320, United States.
Mol Pharm. 2020 Dec 7;17(12):4473-4482. doi: 10.1021/acs.molpharmaceut.0c00552. Epub 2020 Nov 10.
Protein solution viscosity (η) as a function of temperature was measured at a series of protein concentrations under a range of formulation conditions for two monoclonal antibodies (MAbs) and a globular protein (aCgn). Based on theoretical arguments, a strong temperature dependence for protein-protein interactions (PPI) indicates highly anisotropic, short-ranged attractions that could lead to higher solution viscosities. The semi-empirical Ross-Minton model was used to determine the apparent intrinsic viscosity, shape, and "crowding" factors for each protein as a function of temperature and formulation conditions. The apparent intrinsic viscosity was independent of temperature for aCgn, while a slight decrease with increasing temperature was observed for the MAbs. The temperature dependence of solution viscosity was analyzed using the Andrade-Eyring equation to determine the effective activation energy of viscous flow (). While values were different for each protein, they were independent of formulation conditions for a given protein. PPI were quantified via the osmotic second virial coefficient () and the protein diffusion interaction parameter () as a function of temperature under the same formulation conditions as the viscosity measurements. Net interactions ranged from strongly attractive to repulsive by changing formulation pH and ionic strength for each protein. Overall, larger activation energies for PPI corresponded to larger activation energies for η, and those were predictive of the highest η values at higher protein concentrations.
在两种单克隆抗体（MAb）和一种球形蛋白（aCgn）的一系列制剂条件下，测量了一系列蛋白浓度下的蛋白溶液黏度（η）与温度的关系。基于理论论证，蛋白-蛋白相互作用（PPI）的强温度依赖性表明存在高度各向异性、短程吸引力，这可能导致溶液黏度升高。采用半经验的 Ross-Minton 模型来确定每种蛋白的表观特性黏度、形状和“拥挤”因子随温度和制剂条件的变化。aCgn 的表观特性黏度与温度无关，而 MAb 的表观特性黏度则随温度略有下降。通过 Andrade-Eyring 方程分析溶液黏度的温度依赖性，以确定粘性流的有效活化能（Ea）。虽然每个蛋白的 Ea 值不同，但在给定蛋白的相同制剂条件下，Ea 值是独立的。通过渗透压第二维里系数（B22）和蛋白扩散相互作用参数（D）来量化 PPI，这些参数在与黏度测量相同的制剂条件下随温度而变化。通过改变每种蛋白的制剂 pH 值和离子强度，可以使净相互作用从强吸引变为强排斥。总体而言，PPI 的较大活化能对应于 η 的较大活化能，且那些可以预测在较高蛋白浓度下达到最高 η 值的情况。
