STABILIZATION OF FULLY ACTIVE CHYMOPAPAIN BY LYOPHILIZATION

The use of maltodextrins, partially hydrolysed starches, was evaluated for the stabilization of fully activated chymopapain, a cysteine prot einase from the papaya latex. Chymopapain was fully activated with cys teine and Na,EDTA. Enzyme activity was determined before and after the stabilization of chymopapain by lyophilization, in the presence of di fferent amounts of lyoprotectants. During 3 years, the stability of on e of the formulations was evaluated. Differential Scanning Calorimetry (DSC) was used to determine the shelf temperature oi these products, while X-ray diffraction was used to determine the crystallinity of the products. The water content was determined using Karl-Fisher titratio n. Maltodextrins were found to protect the fully active chymopapain du ring the lyophilization process. The protection was dependent on their dextrose equivalent (DE) value and independent on the concentration u sed (2-5% w/v). The degree oi protection was as good as that obtained by sucrose. The activity of chymopapain, stabilized by maltodextrin DE 28, was constant when stored for 3 years at room temperature, Freeze- dried cakes of maltodextrin formulations, containing small amounts of cysteine aad Na(2)EDTA, were amorphous. Maltodextrins can be considere d as potential lyoprotectants in the lyophilization of fully active cy steine proteinases. (C) 1997 Elsevier Science B.V.