Lump formation in Filtration and Drying of Particulate APIs

Abstract

Crystallization, filtration and drying are important separation and purification unit operations in the pharmaceutical and speciality chemical industries. Continuous processing technologies have emerged as a promising alternative to the more conventional batch processing. Previous studies primarily focus on crystallization and as a result subsequent stage of filtration and drying are overlooked. In the present short communication, a phenomenological parallel is drawn with the drying of porous solids, studies for which are relatively widely reported. Such analysis helps to identify, the fundamental cause for lump formation, and possible mitigation strategies. Based on the postulated physical scenario, two prototype designs to intensify continuous operation of filtration and drying units are discussed. The prototype solutions could make it possible to intensify or combine multiple stages of filtration, deliquoring, washing and drying thus enabling efficient continuous processing of solid form pharmaceutical and specialty chemicals.