Determination of Moisture in Organic Zinc Drugs by Karl-Fischer Titration

In the Karl-Fischer titrimetric determination of moisture in drugs of organic zinc salts, a modification was made by dissolving the sample with CH3OH-NH3 (180+1 by mass) solution. It was found that the sample was easier to be dissolved and its water of crystallization was completely released by using this solvent. In analyzing 9 drug samples by the proposed method, results obtained were higher than those obtained by the pharmacopeial method. Values of RSD′s (n=5) found were in the range of 0.13%-0.36%.