Method of determining residual moisture content during secondary drying in a freeze-drying process

摘要

A method for determining the residual moisture content during secondary drying in the dry product of a freeze-drying process is disclosed. In order to determine the residual moisture content without interruption of the drying process is suggested that the desorption rate is measured at certain intervals (for example 10 minutes) during the secondary drying phase. A computer calculates from two or several of these measured values the time at which a desorption rate would be reached (desorption rate zero point) which would alter the desired residual moisture by only a tolerably small amount. The respective residual moisture is determined by the computer by chronological integration of desorption rates from zero point until the moment of measurement taking.