Compression prediction accuracy from small scale compaction studies to production presses

• Ejection force measured at small scale has predicted tablet failure at large scale.
• Tablets with ejection shear stresses greater than 3 MPa are likely to have defects.
• Different geometry tablets were compared using tensile strength and solid fraction.
• Minimal material was used at small scale to understand manufacturing at large scale.

Small scale compaction studies which utilise equipment representative of commercial scale tablet presses can be used to develop process understanding of pharmaceutical formulations using minimal quantities of material. In this study the scalability of compressibility (solid fraction vs. compaction pressure), tabletability (tensile strength vs. compaction pressure), compactibility (tensile strength vs. solid fraction) and ejection shear stress was examined over an eight-fold range in tablet size. Tablets of two representative commercially manufactured formulations were compressed and compared using a small scale compaction press and large scale industrial press. Different tablet sizes and shapes were produced from the two types of press. One formulation was manufactured by direction compression and the other by wet granulation. Generally, good agreement was found across the scales for all the measures assessed. In addition, the measurement of ejection shear stress data on the small scale was able to accurately predict tablet failure on commercial rotary presses.

Data collected from a bench top tablet press have been applied to understanding commercial manufacture by the measurement of tablet tensile strength and solid fraction. Ejection shear stress data collected at small scale has predicted the occurrence of tablet defects on commercial rotary presses, where shear stresses greater than 3 MPa are likely to produce defects.Figure optionsDownload as PowerPoint slide