Expert Advice

The process and mechanics of freeze drying are interrelated.  The success of a particular processed product depends upon many complex sub systems. Knowledge gained from many different disciplines is required to ensure that the process is supported in the proper way by the refrigeration, heat transfer, vacuum, cleaning and sterilization systems.  Likewise, the data acquisition system and controls governing these systems must operate in perfect harmony.

In practice companies must have many resources in refrigeration, controls, process, instrumentation, and maintenance. If one or more of these are missing, call on Applewood Scientific. We can provide one or all of these resources.

Narrative:  What a perfect freeze drying acquisition program could look like:

    The ideal freeze dryer for a specific application will be delivered, commissioned, and qualified on time, and will fit inside the space perfectly. Engineering at your company will have strategically placed floor drains, and equipment positions with adequate ups and downs for wiring and piping. There are no obstructions to maintenance personnel, no pipes on the floor that prevent access, no tags that are obscured, validation ports on chamber and condenser provided with accessory  pre-made sensor feed throughs [That don’t leak, are vacuum and SIP pressure tight, and with sufficient probes to run everywhere in the system], and each drain sensor to be provided with a capped tee connection for ease in validation confirmation sensors, and repair logistic, and the facility allows for efficient operation with operators able to load recipes and monitor cycles without gowning up and without having to traverse a circuitous path to get to the controls. The machine is able to be loaded without hovering hands. The process from formulation through capping will pass a media fill and the dryer will have a media fill cycle [which is quite special] to accomplish the pseudo freeze-drying cycle. The freeze dryer will have a simple dry run program that can be run before each batch that will automatically test its capabilities. The CIP and SIP water intrusion filter test [WIT] and drying phase will proceed in sequence automtically, without fault, and cooling the system will maintain sterility until the batch is loaded. The cycle chosen will incorporate a freezing regimen that does not break vials during the process [due to the mannitol excipient] and the cycle will end when the next shift needs it to end, for stoppering and capping. If acceptable for the product the freezing cycle may incorporate controlled nucleation.  The product during the entire process until capping will be protected in a class A environment. The machine will then undergo condenser defrost, then CIP without any faults like water buildup, and then the system shall undergo SIP at the appropriate time before the next cycle to ensure that the system “storage time before next cycle” is observed. The adequate number of cycles can be run in a year. No batches will be lost, because the validation process incorporates a process envelope that produces product with consistent moisture content, meets sterility tests, and meets or exceeds the expiry date even if during drying the environmental conditions and operational performance are not optimal within the process envelope. The freeze dryer will allow for easy calibration, revalidation, and maintenance over its useful lifetime.

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