(T1530-07-41) Comparison of Trehalose and Sucrose in Preserving and Stabilizing Lyophilized Therapeutic Proteins

Purpose: Simple sugars, especially disaccharides, stabilize and preserve therapeutic proteins of various composition both in their liquid and solid states. Therapeutic proteins are normally formulated at a wide range of concentrations and undergo process development, storage, and administration at various temperatures. In most cases, freeze-drying is the preferred method to manufacture therapeutic proteins in their solid state, thus the understanding of the correlation among excipient properties, formulation composition, processing conditions and lyophilized cake properties remains of great interest. Moreover, the stability of the lyophilized cake as function of storage temperature is critical to developing a robust formulation with desirable biological performance. The present study aims to understand the properties of VialoseTM ultra-pure trehalose and investigate its impact on the preparation and stabilization of lyophilized cakes, in the presence and absence of a model therapeutic protein, bovine serum albumin (BSA). Sucrose was selected as a benchmark to compare their properties and performance in preserving /stabilizing lyophilized BSA.

Methods: Vialose^TM ultra-pure trehalose is manufactured by Ashland Specialty Ingredients. BSA solutions with and without disaccharide (trehalose or sucrose) were lyophilized under different conditions, and the properties of lyophilized cake, such as appearance and water content, were evaluated. In addition, the lyophilized BSA and BSA formulations were stressed at 40^oC and the stability of BSA was monitored as a function of time.

Results: In a comparison with sucrose, Vialose^TM ultra-pure trehalose showed a higher glass transition temperature, thus could form a stronger glass, which had very high viscosity and low mobility leading to the increased stability of the therapeutic proteins being preserved. The higher glass transition temperature of trehalose also resulted in 2-3°C higher collapse temperature of the trehalose vs. sucrose frozen solutions. At a primary drying temperature that is suitable for trehalose, non-uniform /collapsed appearance was observed throughout the lyophilized cakes that contains sucrose. The stability of BSA after storage under accelerated conditions indicated that both trehalose and sucrose are efficient at stabilizing this model compound. However, an accelerate stability test on both disaccharides indicated that sucrose has higher risk to hydrolyze into reducing sugars glucose and fructose, which indicated its potential risk of jeopardizing the stability of some therapeutic proteins.

Conclusion: In summary, Vialose^TM ultra-pure trehalose is a non-reducing sugar with high Tg and low chemical reactivity that efficiently stabilized BSA under accelerated condition. Due to its high glass transition temperature, it can be lyophilized at 2-3 °C higher primary drying temperature than sucrose, which enables more time and cost efficient lyophilization process. In addition, trehalose does not degrade into reducing sugars thus minimizes the formulation chemical stability risk.


Figure 1. glass transition temperature (Tg) of trehalose (left) and sucrose (right) solutions
Green: 1%, Blue: 5% and red: 10%


Figure 2. lyophilized BSA cakes from 1% Trehalose or Sucrose, 0.01% polysorbate 20 water solution. Primary drying temperature is -28oC.