Jasmine Rowe, Megerle Scherholz, Weixian Shi, Bereket Yohannes, Prit Lakhani, Bo Lang, Monika Lavan, Kyle Martin
Sticking and picking continue to be problematic for tableting operations, despite decades of research on this topic. Sticking occurs when powder adheres to the punch face to the extent that defects are observed on the tablet surface; picking is a subset of sticking that occurs near debossed characters on the tablet face. The cause of sticking is attributed to stronger adhesion stresses between the powder and punch surface compared to the cohesive stresses of the powder within the tablet. Sticking can be costly for a product, causing unacceptable tablet quality and incomplete or missing logos on the tablets, potentially resulting in product rejection and thus reduced process yields. Additionally, the presence of sticking requires that tablet press tooling be cleaned more frequently, leading to longer manufacturing times and additional yield losses.
A significant obstacle in mitigating sticking challenges is that they tend to manifest during commercial-scale operations, even for processes deemed low-risk throughout development. To better identify sticking risk during earlier stages of development, we have evaluated the feasibility of an instrumented “adhesion” punch to quantify sticking risk at lab-scale (<20 g powder blend) and its ability to predict sticking propensity during pilot-scale manufacture (>3 kg powder blend). Preliminary results indicate that while the adhesion punch appeared to discern between powders with significantly different “sticking” behavior, the measured adhesion forces were convoluted with contributions from frictional forces (punch/die-wall, powder/die-wall). For powder blends with more subtle differences, i.e. 1% vs. 1.5% lubricant level, the contribution from frictional forces appeared to dominate the adhesion force measurements and consistent correlations to “sticking” performance at pilot-scale could not be made. Method development on the adhesion punch that led us to this conclusion will be discussed and demonstrated through select case studies.
Jasmine Rowe
Jasmine Rowe is a senior research investigator within the Engineering Technologies group at Bristol-Myers Squibb (BMS). She leads a team whose efforts span both oral solid and parenteral dosage formulation development, with a strong emphasis on the development and implementation of material-sparing tools, techniques, and models to streamline
development activities. She earned her Ph.D. in chemical engineering from the University of Texas at Austin.