Chromatography Forum

The Related substances monograph of Betaxolol Eye Drops, Solution in British Pharmacopoeia states that:


In the chromatogram obtained with solution (1) the area of any secondary peak is not greater than the area of the principal peak in the chromatogram obtained with solution (2) (1%) and the area of not more than one such peak is greater than 0.3 times the area of the principal peak in the chromatogram obtained with solution (2) (0.3%).



Can we interpret that “Sum of all impuritiesâ€

The language is certainly convoluted, but I read it as

"any number of peaks less than 0.3%, a maximum of 1 peak between 0.3% and 1%, and no peaks greater than 1%".

I don't see anything in there that limits the total percentage of impurity peaks.

Tom, your interprepretation is a model of clarity.
Does the BP employ someone who is paid to obfuscate? Maybe they write logic puzzles in their spare time.

I always strive to eschew obfuscation!