ABSTRACT
In 1909, Shackell [1] realized that in order to successfully lyophilize a formulation, it was necessary to freeze the substance prior to the start of the drying process. A cursory review of the scientific literature shows that many early and current investigators reporting results of a lyophilization process merely state that the product was first frozen to a given temperature but provide little or no information regarding the nature of the freezing process [2-14]. A number of those references cited are of investigators who have contributed to the advancement of lyophilization as a sci~nce. These references are cited to stress the point that even the most experienced investigators have at times overlooked the importance of the freezing process or have not provided the rationale for selecting a given freezing process.
