Chromatography Forum

hello every body

I have a couple of questions to you an thank you for your opinion.

I use frequently standard impurities USP in my lab ,for raw material analisys by HPLC.

my question is : can i store this solution for many weeks and use again and again?

Is it Legal...i,e how can I reply to a judge advocate or to a regulator entity if I declarate this procedure and how can i justify it?
Tankyou very much to all
Pduque

The only way to truly prove that it would be valid to store and use this solution multiple times is to perform a stability study over the days/weeks of time you would intend to use.

If you show that the solution performs reproducible results over time you may have a leg to stand on. Reproducible results though may be in the eyes of the beholder...

For GMP/FDA compliance I have to prove stability of my sample and standard solutions as part of validation. Without this proof it is assumed your solutions are prepared fresh per use that day (no stability).