Effect of formulation composition on trastuzumab stability

Abstract

For monoclonal antibody drug products as for other biologics, while the innovator drug products first becomes commercially available, they are often followed by one or more biosimilar products. These biosimilars often differ from the innovator product, as well as from each other, in their formulation composition. However, the impact of the formulation composition on the stability of the active pharmaceutical ingredient subjected to different ‘stresses’ is still not understood.

Highlights

Tmab was extracted from one source and reformulated into four different commercial formulations.

Effects of formulation compositions on structural stability and aggregation of monoclonal antibody (trastuzumab) during freeze-drying, freeze–thaw and agitation was studied.

Tmab showed good conformational stability against all stress conditions, irrespective of their formulation compositions.

Partial increase in insoluble aggregation was observed upon agitation of sorbitol based Tmab formulation.

We have evaluated the effect of different formulations on structural stability and aggregation behavior of a monoclonal antibody, trastuzumab (both the drug substance and the final drug product), against three most common stresses encountered during production, storage, and formulation into a lyophilized product − freeze–thaw, freeze-drying, and agitation. Irrespective of the stabilizer used, the formulations exhibited good conformational stability against all three stresses. However, the freeze-drying process caused a significant increase in the number of soluble aggregates, but only in sucrose containing formulations. On the other hand, agitation in sorbitol containing formulation led to a significant increase in insoluble aggregates.

This effect could also be attributed to the absence of surfactant in this formulation composition. The stabilizing effect of trehalose appeared to be independent of its concentration. Therefore, the effect of formulation composition is more pronounced for aggregation of trastuzumab than for its conformational stability. Our findings suggest that formulation design warrants consideration of both conformational stability and aggregation behavior of the active ingredient.

Materials

Sucrose, trehalose dihydrate and the buffer components L-histidine and L-histidine hydrochloride (HCl) were purchased from Pfanstiehl (Waukegan, IL, USA). The surfactants including polysorbate 20 and PEG 3350 were procured from Thermo scientific (Waltham, MA, USA) and VWR life science (Atlanta, GA USA) respectively. Sorbitol and thioflavin T were obtained from Sigma Aldrich (St. Louis, MO, USA). Trastuzumab-pkrb (Tmab) drug product (Herzuma®, Celltrion Healthcare, South Korea) was purchased.

Aziz Ahmad, Hesham Refaat, Sanghati Bhattacharya, Vadim J. Gurvich, Anurag S. Rathore, Reza Nejadnik, Raj Suryanarayanan, Effect of formulation composition on trastuzumab stability, International Journal of Pharmaceutics, 2025, 125275, ISSN 0378-5173, https://doi.org/10.1016/j.ijpharm.2025.125275.