TITLE:
Use of Thermogravimetric Analysis for Moisture Determination in Difficult Lyophilized Biological Samples
AUTHORS:
Paul Matejtschuk, Chinwe Duru, Kiran Malik, Ernest Ezeajughi, Elaine Gray, Sanj Raut, Fatme Mawas
KEYWORDS:
Thermogravimetric Analysis, Freeze Dried, Moisture Determination, Karl Fischer Titration
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.7 No.3,
March
15,
2016
ABSTRACT: Residual moisture
is a key quality control parameter for lyophilized biologicals, as high
moisture can correlate with poor stability. Coulometric Karl Fischer titration
is the most widely used technology to determine residual water content; some
chemicals are known to cause problems with Karl Fischer titration, but these
chemicals do not usually occur in biologics. Three biological samples, of
fibrinogen, heparin and Haemophilus
influenza b polysaccharide, have caused particular issue in our hands by
routine Karl Fischer analysis, illustrating different limitations with this
method. The use of thermogravimetric analysis, with evolved gas mass
spectrometric monitoring, is described here as a successful alternative for
moisture analysis in these materials.