Sticking and picking during tablet manufacture has received increasing interest recently, as it causes tablet defects, downtime in manufacturing, and yield losses. The capricious nature of the problem means that it can appear at any stage of the development cycle, even when it has been deemed as low risk by models, tests, and previous experience. In many cases, the problem manifests when transferring the process from one manufacturing site to another. Site transfers are more common now than in previous times because of the multinational nature of drug product manufacturing and the need for redundancy in manufacturing networks. Sticking is a multifactorial problem, so one single “fix” is unlikely to solve it completely, and “solutions” addressing one problem may exacerbate another. A broad-based strategy involving the API, formulation, tablet tooling, and the manufacturing process is the most likely approach to provide a robust and lasting solution. When faced with a sticking problem for the first or subsequent time, the formulator should address, in a structured way, a range of possible causes and remedies. In this article, we focus on current research and practice; on some of the common causes of sticking; mitigation and resolution strategies and solutions; and possible future directions in research.
Summary & Conclusion
Sticking to tablet tooling is an area of increasing interest to the pharmaceutical industry, and
therefore to researchers in the field. It is a multifactorial problem, with the properties of the tablet
machine and the rate at which it is operating, tooling, powder properties, formulation components,
and manufacturing process, all interacting to lead to sticking or picking in an individual situation.
The issue can take time to emerge, both during the formulation cycle from small scale to commercial scale, or during transfers of single scales from one site to another, thus making the problem time critical to the organization experiencing it. Extensive knowledge of the system under development is required to pre-empt or prevent sticking problems. However, when it arises, the solution is likely to require understanding of the materials (API and excipients), formulation, tooling and the press before the problem(s) can be fully understood and therefore solved