Fillers and Binders | Essential for Stable and High-Quality Tablets
Fillers in tableting
Strictly speaking, fillers should only fill up the missing tablet mass and be as inert as possible. This means that they should not interact with the API or other necessary excipients.
Functional fillers
However, it makes no sense to add inert substances which are non-binding or have no other functionality. That’s why often so-called functional fillers are used. They, for example, contribute to the tablet strength with their own excellent bonding capacity.
Binders in solid dosage forms
Binders can be classified in two groups, wet and dry binders. Both have the task to bind together particles.
Wet binders
Contrary to what the word suggests, wet binders are also solid. They are used in wet granulation where they are dissolved in the granulation liquid and applied to the power. Upon drying they glue together the powder particles and form the granulate.
Dry binders
Dry binders have a high bonding capacity and help to increase the bonding capacity of the whole formulation. This is important for the dry granulation with e.g., roller compactors, because the granulation principle relies on the formation of intermediate compacts. Other than dry binders used for direct compression or as post-granular excipients, dry binders for roller compaction don’t need to be flowable.
Dry binders or Functional filler
Especially for excipients for direct compression or post-granular excipients the definitions of functional fillers and dry binders are blurred. Both have the function to increase the strength of the tableting formulation.
Functional fillers and binders make the difference – and we are here to help you find the optimal solution.
Read also:
Resource: Solids Development Consult
