2017 年 77 巻 3 号 p. 164-176
Flowability is one of the most important parameters of pharmaceutical powders during the handling and preparation of solid dosage forms. It is especially important to characterize the very poor flowability that some herbal powders show. In this study, the flowability of a traditional herbal powder formulated as an antitussive and expectorant was examined. This formulated herbal powder and two excipient powders, precipitated calcium carbonate and anhydrous dibasic calcium phosphate, were evaluated using two instruments. A shearing test, a wall friction test and a dynamic flowability test were performed with Powder Rheometer FT4 (Freeman Technology, Tewkesbury, UK). Internal friction and wall friction were measured. BFE (basic flow energy), SI (stability index) and FRI (flow rate index) were also measured. Angle of repose, bulk density, tapped density, angle of spatula and cohesiveness were measured with a Powder Tester (Hosokawa Micron, Osaka, Japan). The results were used to calculate Carr's Index values and compressibility, which in turn revealed that this herbal powder had poor flowability.
The other aim of this study was to develop a new method of evaluating the flowability of powder through a medicine spoon. Two evaluation methods, the spoon-tap test and the consecutive medicine spoon test, were developed to design a new medicine spoon for the herbal powder. The results of these tests indicated that a polyethylene medicine spoon with holes at the bottom could reduce the adhesiveness to a medicine spoon of the formulated herbal powder.