Jerome B. Johnson, Anton Kulchitsky, Dmytro Cherepakha
Punch sticking is a function of the molecular and particle structure1, and physicotechnical2 properties of pharmaceutical powders used in the manufacture of tablets. Molecular and particle structure properties define the attributes of individual API and excipient particles that help determine their cohesive and adhesive properties within the bulk and against a punch surface. Physicotechnical properties describe the bulk behavior of the powder due to the interaction of individual particles within the aggregate and with other objects, such as punch surfaces, under the influence of external forces. We report on particle mechanics simulations of the discrete process of particles with high effective adhesion (Ap) to a punch surface, compared to effective adhesion (Ab) to adjacent particles in the bulk. Effective adhesion is the overall adhesion that may be due to the combined effects of several different mechanisms. A small number of high effective adhesion particles accumulate on the punch during each powder compaction cycle until a critical mass of particles on the punch adheres to a tablet surface causing a tension failure of cohesive particle bonds within the tablet during a compaction cycle that can interrupt a production run. We produce a failure map, for a two-component powder, of the number of cycles to produce particle sticking induced tablet failure as a function Ap/ Ab, and particle mixture ratio of API to excipient particles PAPI as a function of average particle cohesion. Using particle cohesion and adhesion data it may be possible to estimate the potential of particle sticking severity over a wide range of powder conditions, with less experimental effort, using particle mechanics modeling.
References:
1. Chattoraj, S. et al. Sticking and Picking in Pharmaceutical Tablet Compression: An IQ Consortium Review. J. Pharm. Sci. 107, 2267–2282 (2018).
2. Leuenberger, H. & Rohera, B. D. Fundamentals of powder compression. I. The compactibility and compressibility of pharmaceutical powders. Pharm. Res. 3, 12–22 (1986).
Jerome B. Johnson
Dr. Jerome (Jerry) Johnson has degrees in physics, mathematics, and geophysics (Ph.D.). He has over 35 years of applied research experience, solving problems of Arctic infrastructure and engineering; military operations; space exploration and engineering; and resource utilization for government, academia, and the private sector. Dr. Johnson led individual and large team projects to determine ice forces on offshore structures, snow effects on mine neutralization, tools to find resources on the moon, the physics of tire/snow interaction, constraints to Mars rover mobility, penetration in granular materials, and renewable marine energy. He was director of the Alaska Hydrokinetic Energy Research Center and a participating scientist on the Mars Polar Lander and Mars Exploration Rovers NASA missions. He is a Co-I on the CAESAR comet sample return mission proposal, which seeks to return a volatile rich sample from comet 67P. He co-developed, with Anton Kulchitsky, the Polyphysica particle dynamics model, and he is an expert in granular media mechanics. Dr. Johnson was a senior engineer at Oceanographic Services, Inc., a scientist at ERDC’s Cold Regions Research and Engineering Laboratory, and a research professor at the University of Alaska, Fairbanks. He is currently CEO of Coupi, Inc. and an adjunct research professor at the University of Alaska, Fairbanks.