With the exception of salmon calcitonin, sub-micron sucrose showed larger adhesive interactions to the selected APIs than anhydrous sub-micron alpha-lactose.

In addition, both AFM and CA surface energy measurements also showed that sub-micron sucrose has a higher surface energy than anhydrous sub-micron alpha-lactose.

Conclusions: Anhydrous sub-micron alpha-lactose has been found to have lower adhesive interactions with a range of chosen, low-dose APIs compared to sub-micron sucrose.

Corresponding theoretical work of adhesion values between sub-micron sucrose and each API were almost identical to those observed between silk grade sucrose and each API.