Moisture analysis of lyophilized allergenic extracts

A simple, relatively fast, coulometric method to determine both the surface-moisture and bound-moisture content of a wide variety of lyophilized, allergenic extracts has been developed. The method has been found suitable for the detection of residual-moisture levels in both lyophilized protein and carbohydrate samples. Isothermal rate-changes in moisture desorption, normalized with respect to sample size and plotted versus time, yield desorption curves which are characteristic of several individual classes of lyophilized materials. The method, when compared to the Official Loss on Drying Procedure for Lyophilized Biologicals, has proven to be faster (1.5 hr.) and more sensitive, with increased specificity and accuracy.