What is the difference between “dried” and “anhydrous” substances?

Answer:

“Dried substance” takes into account the loss on drying test (including class 3 solvents), whereas “anhydrous substance” refers to the result obtained by the water determination. It is important to note that when a quantitative determination of a residual solvent is carried out and a test for loss on drying is not carried out, the content of residual solvent is taken into account for the calculation of the assay content of the substance, the specific optical rotation and the specific absorbance, even if not explicitly stated in the definition.