Compact and efficient continuous mixing processes for production of food and pharmaceutical powders

Many food and pharmaceutical powders have traditionally been manufactured in batch processes. Especially for larger capacities (>1000 kg/h), the food industry is using continuous processing (e.g. salt mixtures, cereals, chocolate) if the number of mixture components is limited. However, even for lower capacity food and pharmaceutical production, more economical and more efficient production methods will be required in the future, particularly for blockbuster products whose patent protection has expired. The US Food and Drug Administration (FDA) has a large-scale development program that is currently testing the continuous production method. The PAT (Process Analytical Technology) Initiative requires implementation of in-process monitoring systems and controls in the mixing process. Gericke has developed continuous mixing and metering systems for this low-throughput range with the required accuracy, that also meet the highest hygienic requirements. The testing and model calculations demonstrate that the efficiency (statistically expressed as the relative standard deviation) is determined not only by the process parameters such as the average residence time and the metering constancy, but also by the particle size distribution and the concentration range of the active substance. This active substance may be considered to be vitamins in food or active ingredients for pharmaceutical products.