Important issues pertaining to the scale-up of non-reactive coating processes occurring in fluidized bed and rotating drum-coating equipment, used primarily in the pharmaceutical and food industries, are discussed. A description of the scale-up methodology relating to the operation of the coating equipment is presented. For both types of equipment, the physical and chemical characteristics of the solids (tablets or pellets) must remain constant for all scales of equipment. Important issues in fluidized bed coating operations and scale-up such as air flow, product uniformity, air dew-point control, distributor plate design, attrition, atomizing air pressure, coating time, and batch charge are addressed. Specific issues affecting coating operations in rotating perforated pans including coating and drying cycles, air conditioning, rotation rates, batch charge, and nozzle location are also covered. (c) 2004 Elsevier B.V. All rights reserved.