Powder flow and blending


A. Dubey




Predictive Modeling of Pharmaceutical Unit Operations



Granular mixing of disparate particulates is an essential unit operation in many industrial processes but nowhere is it as critical for the product quality as it is in the pharmaceutical industry. This can be attributed to the variety and complexity of the materials that are handled, small dosages that need to be uniformly distributed, and strict regulatory control over processes and products. Hence powder mixing in the pharmaceutical context receives much attention.Significant efforts are invested in preparing and maintaining blend quality through the process chain. A variety of batch and continuous processing equipment is available for this purpose and much of it have been experimentally and mathematically characterized. A fundamental mixture assessment framework is available, and so is a wide variety of spectroscopic techniques and associated instrumentation for blend characterization. Several numerical techniques have been developed for predictive modeling of the mixing operations.This chapter begins with an emphasis on the importance of powder mixing to the industry and underlines the challenges it presents. Fundamentals and techniques of granular mixing are discussed, followed by a description of mixture assessment, measurement, and characterization techniques. The different modeling tools and techniques are detailed with special attention to the mechanistic modeling tools. A case study describing the development of a material model for such a numerical analysis is included and the discussion is rounded off with a note on emerging technologies and future outlook.


Blending, Characterization, mechanistic modeling, Mixing, Pharmaceuticals, solids handling

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