Development of a New Measurement Method to Evaluate the Physical Properties of Granules for Dry Powder Inhalation Produced by New Spouted Bed Type Binderless Granulator

The spouted bed type of binderless granulator is one of the most appropriate methods available for producing granules of dry powder inhalation (DPI) from cohesive fine powder. However the compressive strength of produced granule is too small to be measure by conventional method. In this work a new apparatus was developed to evaluate the strength of such a soft granule. Load and displacement curve of the granule were measured by new method of compressive strength measurement. To observe the compression process of the granule, photographs were taken with a microscopic camera. It was clarified that this measurement method was remarkably useful to evaluate the compressive strength of soft granule.