Inhibition of Tungsten-Induced Protein Aggregation by Cetyl Trimethyl Ammonium Bromide

Abstract

The purpose of this work was to investigate a potential mechanism for the inhibition of tungsten-mediated monoclonal antibody (mAb) biophysical modifications and sub-visible particle formation. A mAb formulation was incubated with tungsten polyanions in the presence and absence of the anionic surfactant and chelating agent diethylene triamine pentaacetic acid (DTPA) or the cationic surfactant cetyl trimethyl ammonium bromide (CTAB). Formulation was characterized by pH, UV-Vis spectroscopy, size exclusion chromatography, intrinsic tryptophan/tyrosine fluorescence, and micro-flow imaging. We conclude that the formulation excipient and cationic surfactant CTAB effectively inhibits biophysical modifications and sub-visible particle formation.

Impact of Residual Impurities and Contaminants on Protein Stability

“…This metal is used during syringe manufacturing and can leach out in significant amounts in the funnel region of a prefilled syringe and facilitate formation of protein particles . Tungsten at ppm levels was adequate to facilitate formation of subvisible particulates or precipitates in monoclonal antibody formulations . Formation of protein precipitates can occur in seconds.…”

“…Since formation of tungsten polyanions is very limited at higher pHs, formulation of proteins above pH 6.0 would be preferable to minimize tungsten‐induced protein aggregation/precipitation . Use of a cationic surfactant cetyl trimethyl ammonium bromide was shown to effectively inhibit tungsten‐induced structural changes and formation of subvisible particles …”

“…175 Tungsten at ppm levels was adequate to facilitate formation of subvisible particulates or precipitates in monoclonal antibody formulations. 176,177 Formation of protein precipitates can occur in seconds. Tungsten-induced protein aggregation/particle formation is not too surprising as this metal can easily bind to many proteins.…”

“…177 Use of a cationic surfactant cetyl trimethyl ammonium bromide was shown to effectively inhibit tungsten-induced structural changes and formation of subvisible particles. 176 Other metal leachables/extractables from borosilicate vials could also interact directly with a protein product or form other complexes with formulation excipients to indirectly influence the stability of proteins. It was recently demonstrated that storage of a phosphate buffer in borosilicate vials at 40 • C led to the formation of aluminum phosphate particulates within months because of the interaction of phosphate with leached aluminum, and the extremely low solubility of the aluminum salt.…”