Using dextran of different molecular weights to achieve faster eeze-drying and improved storage stability of lactate dehydrogenase

Freeze-drying of protein formulations is frequently used to maintain otein activity during storage. The freeze-drying process usually quires long primary drying times because the highest acceptable drying mperature to obtain acceptable products is dependent on the glass ansition temperature of the maximally freeze-concentrated solution -g). On the other hand, retaining protein activity during storage is lated to the glass transition temperature (T-g) of the final eeze-dried product. In this study, dextrans with different molecular ight (1 and 40kDa) and mixtures thereof at the ratio 3:1, 1:1, and 1:3 /w) were used as cryo-/lyoprotectant and their impact on the stability the model protein lactate dehydrogenase (LDH) was investigated at evated temperatures (40 degrees C and 60 degrees C). The dextran rmulations were then compared to formulations containing sucrose as yo-/lyoprotectant. Because of the higher T-g values of the dextrans, e primary drying times could be reduced compared to freeze-drying with crose. Similarly, the higher T-g and T-g of dextrans relative to crose led to benefits during storage which was shown through improved otection of LDH activity.