Requirements for Designing a Freeze Casting Process for Drugs – Rheological Properties of Suspensions

Abstract

AbstractFreeze casting is a useful molding technique for the production of porous, fast dissolving tablets of foods and pharmaceuticals. In order to optimize the freeze casting process, the slurries, and also the characteristics of the freeze‐casted products, multifunctional additives are usually employed. For further applications of these procedures in industrial processes, the suspension characteristics should be known. This case study focuses on the rheological properties of paracetamol suspensions. The effects of modified starch as an additive, the solid loadings, and the temperature on the flow behavior and viscosities of the suspensions were investigated. It was found that most suspensions are thixotropic systems. The viscosity of the suspensions is highly sensitive with respect to the studied factors, such as shear rate, shearing time, temperature, solid loading, and additive content. Optimized conditions were found and are recommended for industrial use.