Fluidized bed dryers use hot air to fluidize granules for drying. They have a perforated bottom through which hot air passes to lift the granules into a fluidized state where they are suspended in the air stream. This allows for direct contact between particles and air, facilitating efficient moisture removal. Fluidized bed dryers are commonly used in pharmaceutical manufacturing for drying granules during tableting. Validation of a fluidized bed dryer involves design qualification to ensure proper construction, installation qualification to verify installation meets specifications, operational qualification to test functionality, and performance qualification to evaluate drying performance with trial batches.