(T1030-08-49) Combination of Hydroxypropyl-Beta-Cyclodextrin and Trehalose for Improved Stability of Spray-Dried Monoclonal Antibodies

Purpose: Developing a stabilized spray-dried formulation for proteins is one key approach to extending the stability of a dehydrated drug product and providing a broad range of different drug delivery applications. Trehalose has been extensively studied as an excipient to preserve the protein stability in spray-dried formulations. However, the hygroscopic nature of amorphous trehalose makes it prone to recrystallization upon exposure to high temperature and humidity conditions, which can be detrimental to protein stability in the solid state. Herein, we report a formulation approach with the use of 2-hydroxypropyl-β-cyclodextrin (HPβCD) in combination with trehalose to enhance the physical stability of spray-dried solids by inhibiting or delaying the recrystallization of trehalose.

Methods: Solid-state stability profiles of different spraydried mAb1 formulations consisting of trehalose, HPβCD, or a combination of both excipients were evaluated via powder X ray diffraction (PXRD), and the structural changes in proteins in the solid state were evaluated via attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. In addition, chemical degradation and protein aggregation profiles in terms of soluble aggregates such as high-molecular-weight species (HMWS) and subvisible particles (SVPs) after stress were characterized. In particular, we investigated different protein-to-excipient ratios to understand the crystallization tendency of trehalose in spray-dried solids.

Results: In the solid state, HPβCD can inhibit trehalose recrystallization of spray-dried solids exposed to stress conditions of higher temperatures and humidity. The recrystallization tendency of trehalose was found to be dependent on the protein-to-excipient mass ratios. At a 1:1 protein-to-excipient mass ratio, trehalose is insufficient to ensure adequate protein stability after stress under high humidity, which leads to a significant change in conformational stability and the highest degree of subvisible particle formation for mAb1, primarily due to trehalose recrystallization and high-temperature stresses, while the combination of HPβCD and trehalose has resulted in improved protein stability with a reduction in aggregation propensity.

Conclusion: This work evaluated the combination of HPβCD and trehalose as a formulation approach to improve the protein stability of spray-dried formulations in the solid state and established an understanding of using HPβCD as a crystallization inhibitor to delay trehalose recrystallization for protein spray-dried formulations.  Overall, the implementation of HPβCD in combination with trehalose provides additional benefits in delaying trehalose recrystallization and improving the protein stability of spray-dried formulations with respect to soluble aggregates and subvisible particles.

References: doi://10.1021/acs.molpharmaceut.5c00639

Acknowledgements: The authors declare no competing financial interest

Schematic illustration of the spray drying process for monoclonal antibody formulation.

PXRD patterns of spray-dried mAb1 in different formulations after stress at 40 °C/75% RH for 4 weeks

Changes in percent monomer over 4 weeks at 40 °C/75% RH for spray-dried mAb1.