Maltodextrins as lyoprotectants in the lyophilization of a model protein, LDH.
OBJECTIVE
Maltodextrins, partially hydrolysed starches, were evaluated as potential lyoprotectants and the effect of combinations of maltodextrins and PEG 8000 on the protection of lactate dehydrogenase (LDH) was examined.


METHODS
LDH activity assays were performed immediately before freezing and after reconstruction. The activity recovery was used as the parameter to evaluate the lyoprotectants. Differential Scanning Calorimetry (DSC) was used to measure the glass transition temperature (Tg') of the solutions. DSC and X ray diffraction were used to characterise the freeze-dried products.


RESULTS
Maltodextrins were found to protect LDH against inactivation during freeze-drying. The lyoprotection obtained by these maltodextrins is dependent on their D.E. value and the concentration used. The maltodextrin formulations performed as good or better than those containing sucrose and maltose, depending on the concentration used. Freeze dried cakes of maltodextrin formulations were amorphous. In the case of low D.E. maltodextrins, lyoprotection was improved by the addition of PEG 8000 as a cryoprotectant.


CONCLUSIONS
Maltodextrins could be considered as potential lyoprotectants in lyophilization of proteins.
Corveleyn
S
S
Laboratory of Pharmaceutical Technology, University of Gent, Belgium.
Remon
J P
JP
D000818:Animals; D005612:Freeze Drying; D007770:L-Lactate Dehydrogenase / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*; D011817:Rabbits; D012996:Solutions
D011134:Polysaccharides; D012996:Solutions; D011092:Polyethylene Glycols; C008315:maltodextrin; D007770:L-Lactate Dehydrogenase