Heljo P, Ross A, Zarraga I E, Pappenberger A, Mahler H-C
Pharmaceutical Development & Supplies, Pharma Technical Development Biologics Europe (PTDE), F. Hoffmann - La Roche Ltd., Grenzacherstrasse 124, 4070, Basel, Switzerland.
Division of Pharmaceutical Technology, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland.
Pharm Res. 2015 Oct;32(10):3201-12. doi: 10.1007/s11095-015-1697-z. Epub 2015 Apr 18.
Antimicrobial preservatives are known to interact with proteins and potentially affect their stability in aqueous solutions. In this systematic study, the interactions of a model peptide with three commonly used preservatives, benzyl alcohol, phenol and m-cresol, were evaluated.
The impact on peptide oligomerization was studied using GC-MALS, SEC-MALS and DLS, antimicrobial efficiency of different formulations were studied using the Ph. Eur. antimicrobial efficacy test, and the molecular adsorption of preservative molecules on reversible peptide oligomers was monitored using NMR.
The hydrodynamic radius and molar mass of the peptide oligomers was shown to clearly increase in the presence of m-cresol but less significantly with phenol and benzyl alcohol. The increase in size was most likely caused by peptide self-interactions becoming more attractive, leading to reversible oligomerization. On the other hand, increasing the concentration of peptide in multi-dose formulations led to reduced molecular mobility and decreased antimicrobial efficacy of all preservatives.
Peptide-preservative interactions not only affect peptide self-interactions, but also antimicrobial efficiency of the preservatives and are thus of significant relevance. Adsorption of preservatives on oligomeric states of peptides is proposed as a mechanism to explain this reduced antimicrobial efficacy.
已知抗菌防腐剂会与蛋白质相互作用，并可能影响其在水溶液中的稳定性。在这项系统研究中，评估了一种模型肽与三种常用防腐剂（苯甲醇、苯酚和间甲酚）之间的相互作用。
使用气相色谱 - 多角度激光散射（GC - MALS）、尺寸排阻色谱 - 多角度激光散射（SEC - MALS）和动态光散射（DLS）研究对肽寡聚化的影响，使用欧洲药典抗菌效力试验研究不同制剂的抗菌效率，并使用核磁共振（NMR）监测防腐剂分子在可逆肽寡聚体上的分子吸附。
结果表明，在间甲酚存在下，肽寡聚体的流体力学半径和摩尔质量明显增加，而在苯酚和苯甲醇存在下增加不太显著。尺寸增加最可能是由于肽的自相互作用变得更具吸引力，导致可逆寡聚化。另一方面，在多剂量制剂中增加肽的浓度会导致所有防腐剂的分子流动性降低和抗菌效力下降。
肽 - 防腐剂相互作用不仅影响肽的自相互作用，还影响防腐剂的抗菌效率，因此具有重要意义。提出防腐剂在肽的寡聚状态上的吸附是解释这种抗菌效力降低的一种机制。
