Binders in Pharmaceutical Granulation
Binders or “granulating agents” are a critical formulation component in tablets made by direct compression, as well as dry, wet, and melt granulation, ensuring appropriate plasticity, compactibility, and binding ability. In wet granulation, surface wetting ability to allow adhesion and cohesion between inter-particulate surfaces in the wet state is critical to quality attributes.
Traditionally, binder selection has been an empirical experience and preference of companies and individuals. However, advances in understanding mechanistic and quantitative particle engineering and materials science aspects of granulation and tablet binding now allow a more rational and science-based binder selection process. In this chapter, we review the physical-chemical properties of the major classes of binders in current pharmaceutical and commercial use, and provide a practical, rational guide to binder selection and use in the context of the physical-chemical properties of the substrate and the binder, including incompatibilities caused by impurities.
Recent advances in mechanistic understanding of particle engineering and granulation technology will be discussed in detail, specifically the importance of selecting binders with a focus on appropriate thermo-plastic and deformation characteristics, surface energetics, wetting, spreadability, and mechanical properties of the system.
Article information: Parind M. Desai, Lai Wah Chan, Paul Wan Sia Heng. Handbook of Pharmaceutical Granulation Technology, 2021.