They are classified by the functions they perform in a pharmaceutical dosage form. Principal excipient classifications (functions) are the following:
- Binders
- Disintegrants
- Fillers (diluents)
- Lubricants
- Glidants (flow enhancers)
- Compression aids
- Colors
- Sweeteners
- Preservatives
- Suspensing/dispersing agents
- Film formers/coatings
- Flavors
- Printing inks.