Newly developed surface modification punches treated with alloying techniques reduce sticking during the manufacture of ibuprofen tablets

Sticking is a serious problem during the manufacturing process of tablets. In order to prevent this, we used alloying techniques to prepare metal hardening (MH) and electron beam processing infinite product (EIP) punches with rougher asperity of surfaces than a hard chrome plated (HCr) punch. This study evaluated the anti-sticking properties of the MH and EIP punches compared to the HCr punch, using quantitative scraper force measurements and visual observation, for the manufacture of ibuprofen (Ibu) tablets. The anti-sticking property mechanism of the MH and EIP punches was also confirmed. The amount of Ibu adhering to the punch surface was 66% lower for the MH and EIP punches than for the HCr punch, suggesting a superior anti-sticking property of the MH and EIP punches. The scraper force of the HCr punch was 2.60-4.28 N, while that for the MH and EIP punches was 0.54-1.64 N and 0.42-1.33 N, respectively. The result of X-ray photoelectron spectroscopy suggested that the anti-sticking property of the EIP punch was attributed by the rough asperity as well as existence of low friction substance carbon fluoride on the punch surface. In conclusion, this study provides new evidence for the mechanisms behind the superior anti-sticking property of the MH and EIP punches.