For DDU testing of nasal sprays and nasal aerosols, USP
<601> recommends a mechanical actuation procedure
to control actuation force, speed, stroke length and for
units to be thoroughly shaken prior to firing the dose.
In addition to this, the 2003 FDA guidance on
Bioavailability and Bioequivalence recommends
automated actuation systems for BE assessments to
decrease variability in drug delivery.