Comparative studies of powder flow predictions using milligrams of powder for identifying powder flow issues

• Published in: International journal of pharmaceutics 2022-11, Vol.628, p.122309-122309, Article 122309
• Main Authors: Deng, Tong, Garg, Vivek, Pereira Diaz, Laura, Markl, Daniel, Brown, Cameron, Florence, Alastair, Bradley, Michael S.A.
• Format: Article
• Language: English
• Subjects: Cohesiveness and Bond number; Flowability; Pharmaceutical powders; Shear cell tests; Small quantity of samples
• ISSN: 0378-5173; 1873-3476
• DOI: 10.1016/j.ijpharm.2022.122309

[Display omitted] •Measuring flowability of a powder can be a challenge if sample available is limited.•Powder flowability can be predicted based on a Bond number using 50 mg.•The predictions based on the Bond number are validated using traditional shear cell testers.•Validation shows good correlations between the model and shear cell tests.•The prediction model can be a substitution of a shear cell test if sample available is small. Characterising powder flowability can be challenging when sample quantity is insufficient for a conventional shear cell test, especially in the pharmaceutical industry, where the cost of the active pharmaceutical ingredient (API) used is expensive at an early stage in the drug product development. A previous study demonstrated that powder flowability could be predicted based on powder physical properties and cohesiveness using a small quantity of powder samples (50 mg), but it remained an open question regarding the accuracy of the prediction compared to that measured using industry-standard shear cell testers and its potential to substitute the existing testers. In this study, 16 pharmaceutical powders were selected for a detailed comparative study of the predictive model. The flowability of the powders was predicted using a Bond number and given consolidation stresses, σ1, coupled with the model, where the Bond number represents powder cohesiveness. Compared to the measurements using a Powder Flow Tester (Brookfield) and an FT4 (Freeman Technology) Powder Rheometer shear cell tester, the results showed a good agreement between the predictions and the measurements (15 g) if the available amount of sample is small.