Lyophilization: science or art? La liofilización: ¿ciencia o arte?

Abstract

The freeze-drying (lyophilization) process is defined as a stabilizing process in which a substance is first frozen and then the quantity of the solvent (generally water) is reduced, first by sublimation and then desorption to values that will no longer support bilological activity or chemical reactions. Freeze-drying has been used for several decades on an industrial scale for the stabilization of numerous products, many of which are of biological origin. Although alternative methods are available for this purpose, freeze-drying often remains the method of choice for the dehydration of pharmaceuticals, vaccines, diagnostics and biotechnology products, due to the advantages it can offer in terms of thermal stability and retention of activity, both during the process itself and during subsequent storage of the freeze-dried product. In spite of its extended use, many misunderstandings still surrounded the process, besides the conviction that the freeze-drying is a simple technique that can be applied to any product that request drying. Perhaps the most general mistake made regarding the lyophilization process is its treatment as an art rather than a science.