Evaluation of the drying methods influences on the flowability of multi-components formulation

Abstract Powder flowability is an important aspect to have effectual and productive manufacturing of pharmaceutical tablets. Therefore, this study compared the flowability behaviour in terms of Carr index (CI) and Hausner ratio (Hr) of multi-components formulation of naproxen sodium which dried using different drying techniques. A wet formulation of naproxen sodium, microcrystalline cellulose, and polyvinylpyrrolidone was prepared and subjected to microwave drying and three conventional drying techniques - freeze drying, convective drying and vacuum drying. This study revealed that microwave and freeze drying granules were of the highest CI and Hr with possible flowability, while a vacuum and convective drying had the lower CI and Hr with fair flowability. Modelling the correlation between flowability factors and dried samples were presented. The variability in the particle size and the specific surface area of the dried granules showed significant effects on CI and Hr thereby powder flowability. Although the influences of the drying process on the drug powder flowability were indirect, drying method can improve or degrade the textural properties of resultant dried granules such as particle size, specific surface area, moisture content, friability and degree of amorphous/crystallinity and consequently change their flowability.