Validating and Testing a Fluid Bed System

By Don Rosendale, Validation Group Manager, Vector Corp.

In the course of installing a fluid bed system at a mid-sized pharmaceutical company, Vector Corp. was asked to validate and test the device. Although validation and testing are expensive (between $12,000 and $24,000 is typical), in our experience such validation, when performed by the equipment supplier, is far less expensive than if done in-house or by a third party. Testing and validating critical pharmaceutical equipment on "placebo" runs prevents down time and material losses. Moreover, the value of the products being handled by this system were such that one or two successful production runs more than pays for the cost of validation—a not-uncommon situation in pharmaceuticals.

What is a Fluid Bed?A fluid bed is designed to fluff powders and wet granulations, dry them, and perform multiple operations on the products to improve their compressibility, solubility, flow characteristics, etc. The bed uses an inlet air handler that filters and conditions the air. This particular bed, installed in a GMP facility for generic and name-brand pharmaceuticals, produces agglomerations, granulations, powders, and dries used to make final solid and powdered dose products. Process air is forced up through the product held on a screen inside a chamber; filters positioned above prevent product carryover. This "multi" unit uses several inserts to dry wet granulations, granulate product in either Wurster or straight columns, with a rotor system to form rounded granules of various sizes.

Vector Corp.'s Fluid Bed Processor

Fluid beds typically operate under vacuum and have an inlet air handling system to condition the air to a given temperature and filtration level. Optionally, the inlet air system may dry or humidify the air to a consistent dewpoint level. As it exits the system process air is filtered to meet local environmental regulations.

One blower provides the motive force for the process air supply. A damper or frequency drive controls the overall airflow of the system. By its placement, the exhaust blower maintains a slightly negative pressure so that the pharmaceutical remains in the fluid bed. There are other arrangements, but this is the norm.

Validation is divided into several parts:

Room Validation:

Vector personnel were not able to witness all operational modes of the fluid bed, e.g. operation of the rotor and Wurster inserts. These inserts were tested later during Process Qualifications using placebos.

Performance Qualification may be documented in a similar manner to other validations, with the actions and process documented, the expected results of the process after running, analysis of the actual results with pass/fail criteria. Process Qualifications usually involve formulation details and nuances associated with a particular product or process. Of interest to the FDA is the reliability of the process as it is performed on the equipment. Vector prefers to break these items out separately so that the distinction between process and equipment is clear. As a representative to an OEM, Vector has a vested interest in keeping the equipment and processes well defined and operable. The reporting system installed with a supervisory system is used to maintain batch records.

Go to Part 2

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