Parind Mahendrakumar Desai, Bernice Mei Jin Tan, Celine Valeria Liew, Lai Wah Chan and Paul Wan Sia Heng Pages 5923 - 5929 ( 7 )
Manufacturing of pharmaceutical solids involves different unit operations and processing steps such as powder blending, fluidization, sieving, powder coating, pneumatic conveying and spray drying. During these operations, particles come in contact with other particles, different metallic, glass or polymer surfaces and can become electrically charged. Electrostatic charging often gives a negative connotation as it creates sticking, jamming, segregation or other issues during tablet manufacturing, capsule filling, film packaging and other pharmaceutical operations. A thorough and fundamental appreciation of the current knowledge of mechanisms and the potential outcomes is essential in order to minimize potential risks resulting from this phenomenon. The intent of this review is to discuss the electrostatic properties of pharmaceutical powders, equipment surfaces and devices affecting pharmaceutical processing and product performance. Furthermore, the underlying mechanisms responsible for the electrostatic charging are described and factors affecting electrostatic charging have been reviewed in detail. Feasibility of different methods used in the laboratory and pharmaceutical industry to measure charge propensity and decay has been summarized. Different computational and experimental methods studied have proven that the particle charging is a very complex phenomenon and control of particle charging is extremely important to achieve reliable manufacturing and reproducible product performance.
Electrostatics; electrostatic charging, pharmaceutical processing, product performance, Faraday unit, triboelectric charging.
GEA-NUS Pharmaceutical Processing Research Laboratory, Department of Pharmacy, National University of Singapore, 18 Science Drive 4, Singapore 117543.