Weight loss on drying
The simplest way to get an overview of the
drying behavior of a pharmaceutical sub-
stance is to use a standard method, such
as the USP “Loss on Drying”. The examples
show the weight loss curves of amiloride
dihydrate (above) and imipenem (below).
Imipenem was measured in vacuum at
2.5 kPa. The measurement of the two sam-
ples according to the standard method
resulted in weight losses of 11.8% and
6% due to the release of water. The weight
losses of both substances are within the
tolerances permitted in the monographs.
Measurements such as these are typically
used in control and release analysis.