Question: What is the typical (the industrial ‘norm’) for the expiration date of mobile phases for HPLC, i.e. with buffer and without buffer. Also, what should you do (e.g., measure the pH or run and verify the retention time) if you need to extend the expiration date in extenuating circumstance e.g. shortage of acetonitrile or […]
Tag: MTS Helpdesk
How Much Forced Degradation in a Stress Study?
Question: When I forcibly degrade my drug or drug product to create degradation products, how much degradation should I aim for? Answer: The aim of a forced degradation study is to generate degradation products from a drug which are both realistic and representative, typically for the purposes of assessing degradation pathways, or to create suitable […]
Need to Revalidate Method if HPLC Column is Changed?
Question: I would like to have a ‘back-up’ column for my HPLC method so that I am not reliant on one supplier, but how can I choose one that will be suitable and do I need to validate the method fully on the replacement column? Answer: My preference is to develop a new HPLC method […]
What is Mass Balance in a Forced Degradation Study?
Question: What is the ‘mass balance’ for an analytical method and is it critical that I investigate it as part of method development or method validation? Answer: When used in the context of an analytical method, the term ‘mass balance’ relates to its ability to analyse the degradation products of a drug molecule. A method […]