* * * INSIGHT * * *

Completion of the Primary Drying Process

By

Thomas A. Jennings, Ph.D.

ABSTRACT: One of the most complex problems facing the development of a lyophilization process is the completion of the primary drying process. Even when all the product temperatures have approached that of the shelf temperature, there is a degree of uncertainly as to knowing just when to commence with the secondary drying process. Should the shelf temperature be increased before all of the ice has been sublimated then one may experience partial meltback. The question of partial meltback has already been considered in a previous INSIGHT (see Vol. 1 No. 5). However, this latter INSIGHT did not address the issue as to when is it safe to commence with the secondary drying process. This INSIGHT will briefly review various means for making such a determination. For a more detailed description, the reader is referred to Chapter 8 in Lyophilization - Introduction and Basic Principles.

Volume 3 Number 11                                                                            November 2000

4 Pages          5  References          No Figures

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