title: Effect of Excipients on Liquid-Liquid Phase Separation and Aggregation in Dual Variable Domain Immunoglobulin Protein Solutions.
abstract: Liquid-liquid phase separation (LLPS) and aggregation can reduce the physical stability of therapeutic protein formulations. On undergoing LLPS, the protein-rich phase can promote aggregation during storage due to high concentration of the protein. Effect of different excipients on aggregation in protein solution is well documented; however data on the effect of excipients on LLPS is scarce in the literature. In this study, the effect of four excipients (PEG 400, Tween 80, sucrose, and hydroxypropyl beta-cyclodextrin (HPβCD)) on liquid-liquid phase separation and aggregation in a dual variable domain immunoglobulin protein solution was investigated. Sucrose suppressed both LLPS and aggregation, Tween 80 had no effect on either, and PEG 400 increased LLPS and aggregation. Attractive protein-protein interactions and liquid-liquid phase separation decreased with increasing concentration of HPβCD, indicating its specific binding to the protein. However, HPβCD had no effect on the formation of soluble aggregates and fragments in this study. LLPS and aggregation are highly temperature dependent; at low temperature protein exhibits LLPS, at high temperature protein exhibits aggregation, and at an intermediate temperature both phenomena occur simultaneously depending on the solution conditions.
authors.affiliation: Department of Pharmaceutical Sciences, University of Connecticut , 69 North Eagleville Road, Unit 3092, Storrs, Connecticut 06269, United States.
authors.forename: Ashlesha S
authors.initials: AS
authors.lastname: Raut
authors.affiliation: Department of Pharmaceutical Sciences, University of Connecticut , 69 North Eagleville Road, Unit 3092, Storrs, Connecticut 06269, United States.
authors.forename: Devendra S
authors.initials: DS
authors.lastname: Kalonia
mesh_terms: D005079:Excipients / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry* / Q000378:metabolism*; D007135:Immunoglobulin Variable Region / Q000737:chemistry* / Q000378:metabolism*; D059625:Liquid-Liquid Extraction; D019999:Pharmaceutical Solutions; D044367:Phase Transition; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization
chemical_list: D005079:Excipients; D007074:Immunoglobulin G; D007135:Immunoglobulin Variable Region; D019999:Pharmaceutical Solutions
keywords: PEG; aggregation; excipients; hydroxypropyl beta-cyclodextrin (HPβCD); liquid−liquid phase separation; physical stability; protein formulation; protein−protein interactions; sucrose