Viscosity-Reducing Bulky-Salt Excipients Prevent Gelation of Protein, but Not Carbohydrate, Solutions

The problem of gelation of concentrated protein solutions, which poses challenges for both downstream protein processing and liquid formulations of pharmaceutical proteins, is addressed herein by employing previously discovered viscosity-lowering bulky salts. Procainamide-HCl and the salt of camphor...

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Bibliographic Details
Main Authors: Awanish Kumar, Fnu, Klibanov, Alexander M
Other Authors: Massachusetts Institute of Technology. Department of Biological Engineering
Format: Article
Language:English
Published: Springer US 2018
Online Access:http://hdl.handle.net/1721.1/114442
https://orcid.org/0000-0002-2639-8796
https://orcid.org/0000-0003-3830-714X
Description
Summary:The problem of gelation of concentrated protein solutions, which poses challenges for both downstream protein processing and liquid formulations of pharmaceutical proteins, is addressed herein by employing previously discovered viscosity-lowering bulky salts. Procainamide-HCl and the salt of camphor-10-sulfonic acid with l-arginine (CSA-Arg) greatly retard gelation upon heating and subsequent cooling of the model proteins gelatin and casein in water: Whereas in the absence of additives the proteins form aqueous gels within several hours at room temperature, procainamide-HCl for both proteins and also CSA-Arg for casein prevent gel formation for months under the same conditions. The inhibition of gelation by CSA-Arg stems exclusively from the CSA moiety: CSA-Na was as effective as CSA-Arg, while Arg-HCl was marginally or not effective. The tested bulky salts did not inhibit (and indeed accelerated) temperature-induced gel formation in aqueous solutions of all examined carbohydrates―starch, agarose, alginate, gellan gum, and carrageenan. Keywords: Carbohydrates, Downstream processing of biologics, Gel formation, Hydrophobic salts, Intermolecular interactions in solution, Proteins