Calculation on anhydrous basis

How to decide whether calculation is to be done as per anhydrous basis or on as is basis in liquid oral products?

1 Like

Difference Between PURITY, ASSAY & POTENCY

On as is basis = (Area of sample / Area of standard) x (conc. of standard / conc. of sample) x potency or assay of standard.

On anhydrous basis = (Assay on as is basis / 100 – moisture) x 100.

On dried basis = (Assay on as is basis / 100 – LOD) x 100.


Rule of thumb: Calculate as is unless clearly stated otherwise.

1 Like

What if in calculation formula it is mentioned on anhydrous basis but people have been doing the calculation on as is basis.does that make much difference in assay of the product.

Sir thanks for the prompt reply

That depends on how the API is described in the pharmacopeia. If described .xH2O use as is, if described anhydrous, use anhydrous basis.
Also take into account the API declaration your company makes on the product label, anhydrous or not.