Abstract
Water-content data for various drugs, estimated on the basis of weight decrease in a loss on drying (LOD) test or determined by the Karl-Fisher method (KF), were compared with values obtained with thermogravimetry (TG). TG/mass spectroscopy was also utilized for identification of volatile materials during the weight-loss process. The results suggest that the TG method can be applied to the determination of water content in drugs if their volatile contaminant is only water or the major volatile constituent is water, and that TG can be used as a substitute for the LOD test in cases, where expense or some other factor restrict the available sample size of a drug. It was further indicated that TG can be utilized for some drugs to which the KF method cannot be applied due to their insolubility in KF reagents.
