Overcoming Particle Segregation in the Pharmaceutical and Cosmetics Industries

Segregation (separation) of particles in mixtures is a common problem in many industries. In the pharmaceutical industry such segregation is often of major concern when handling direct compression formulations prior to pressing tablets or capsules. The result can be unacceptable variations in tablet or capsule weights and/or assays. Similarly in the cosmetics industry, particle segregation can cause severe quality control problems.Particle segregation can occur by one of five primary mechanisms, three of which are common in the pharmaceutical and cosmetics industries. Which mechanism is predominant in a given application depends on the physical properties of the material being handled as well as the type of equipment being used.Each of the three common mechanisms will be described in detail. Then typical solutions will be presented for both retrofitting existing facilities as well as designing new plants. While it is not always possible to eliminate segregation, it can usually be minimized to the point that significant gains in product quality can be realized.