By Sharon Nowak
Twin screw feeders are often used as the dispensing and feeding method of choice for difficult flowing pharmaceutical powders. Both gravimetric and volumetric devices are used for a variety of pharmaceutical unit operations including batching operations to reactors and bins, feeding to mills and micronizers, and tablet press lubrication. In addition, high accuracy gravimetric feeders have now become the “heart” of the pharmaceutical continuous process, including continuous direct compression, continuous extrusion and granulation, continuous dry granulation and continuous coating. Base prices of most standard feeders can start as low as $20,000 for volumetric pharmaceutical applications. However, it is important to note that a wide variety of options exist for “pharmaceutical design” feeders, each of which result in a variety of price points. This article will outline several of the options available for pharmaceutical feeder applications and also define the process advantages when considering these options.