Characterization of Freeze Dryers

A lyophilization process is said to be successfully transferred when one can achieve and demonstrate that the product has identical or very comparable thermal history between lab and commercial lyophilizers. Since the lab freeze dryers are built differently than commercial and since the lyophilization process is developed at lab scale, it is imperative that the characteristics of the commercial freeze dryers be understood. This chapter discusses the methodology and techniques in determining those characteristics of freeze dryers whose knowledge and understanding are critical to the design of the freeze-drying process, scale-up/tech transfer from one scale to another or from one freeze dryer to another of same scale, and demonstration of performance equivalency between the freeze dryers.