nonionic surfactants (dodecyl maltoside and polysorbate 20) effect on light induced aggregation and conformational changes of recombinant human ifnβ_1b

liquid protein formulations are prone to form aggregates. the effect of nonionic surfactants such as polysorbate 20 (ps 20) and n-dodecyl β-d-maltoside (ddm) on the prevention of aggregation and conformational changes of recombinant human ifnβ-1b (rhifn β_1b) was explored. polysorbate has been used in formulations of protein pharmaceuticals. there have been concerns about using ps 20 due to its residual peroxide content which may negatively affect protein efficacy. n-dodecyl β-d-maltoside has been of interest and shown to be highly effective in prevention of aggregation. fresh bulk of rhifn β_1b was formulated using ddm or different concentrations of ps 20. formulations were exposed to light stress condition according to the ich guideline of q1b. the overall conformational integrity of individual samples was characterized by a combination of circular dichroism (cd), fluorescence spectroscopy and rp_hplc techniques.the cd spectrum depicting the conformational integrity of rhifn β_1b showed 31.9% and 31.2% decreases in α-helix content of protein samples with 0.2% or 0.02% of ps20 compared to only18.2% of that containing 0.2% ddm. the rp-hplc analysis also showed that the oxidized impurity in formulation containing ddm is less than those contain ps 20. complementary analysis of the liquid formulations using ifr and uv methods also was in compliance with the data obtained by cd.compared to ps 20, the sample of rhifn β_1b formulation with ddm was more resistant to the destruction effect of light. results were in accordance with previous studies and could suggest ddm as a reliable anti-aggregation surfactant in biopharmaceutical formulations.