Flow Properties of Powder Mixtures as Factors of Hard Gelatin Capsule Filling

Abstract

Hard gelatin capsules belong to the most commonly used pharmaceutical solid dosage forms but their filling using capsule filling machines is known to present many problems to their operators. Such problems are caused by relatively complicated requirements on rheological properties of capsule fillings which vary with the filling technique used as those techniques rely on different physical principles. This review provides an overview of automated and semi-automated capsule-filling processes, emphasizing the aspects of processed particulate mixture behavior in the process; this description determines the process requirements on rheological properties of capsule fillings. Rheological properties which can be used to study and optimize the filling process are discussed, as well as methods of improving those properties using the flow additives.