It is important to view product and process development for freeze-dried parenterals as an integrated process rather than
as a collection of independent activities. When doing formulation and initial cycle development, the development scientist
must be aware of the type of equipment to which the product will be transferred in the next stage of development. The scientist
must also understand the capability of the equipment, and must take it into account as cycle conditions are developed. This
approach becomes particularly important for formulations that will withstand aggressive cycle conditions.
To generate a design space similar to the one in this discussion, it is necessary to have a thorough understanding of both
the characteristics of the formulation and the capability of equipment. This is the major intent of the Quality by Design
Steven L. Nail, PhD, is a senior Baxter research scientist at Baxter Pharmaceutical Solutions, Inc., Bloomington, IN, 812.355.7270, steven_nail@baxter.
Jim A. Searles, PhD, is director of development at Aktiv-Dry, LLC, Boulder, CO.
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