Page 1 of 1

amlodipine and valsartan tablets dissolution USP method

Posted: Thu Apr 19, 2018 4:32 pm
by qfiviera
Hi there. I´m having trouble with this analysis, amlodipine besylate.
I cannot get concordance within standards and the biggest problem, areas whitin days vary. I´ve tried all hplc we have (Promeinence, 1260 and 1100) and always same problem. One day in an hplc you get some area, and the other day, same hplc, same mobile phase (or new), and response changes. Tried another standard from different source but nothing different happened, same problem. Instruments are qualified, is the only product I´m seeing this. But not with Valsartan, only amlodipine, and the system is the same because it´s a gradient, you quantify both peaks.
Anyone has experience with this monography?

Re: amlodipine and valsartan tablets dissolution USP method

Posted: Wed May 23, 2018 8:29 pm
by dap
Hello. May amlodipine be just unstable?

Re: amlodipine and valsartan tablets dissolution USP method

Posted: Wed Jun 06, 2018 6:31 am
by danko
You need to work systematically here!

1. Areas change: How? larger/smaller? Progressively or randomly?

2. Do you work wth the sandard or the samples?

3. Do you use the same solutions each day or do you dissolve new samples/standards every day and se these area variations.

Best Regards

Re: amlodipine and valsartan tablets dissolution USP method

Posted: Fri Oct 30, 2020 1:27 pm
by qfiviera
Thank you guys. It is not an stability problem.
We work with secondary standards, solutions prepared at the moment of use.
Areas differ randomly.