Author: MTS

Replicates in Analytical Methods: When and How Many?

Do you prepare your samples/standards in duplicate without really thinking about it? If challenged on why, would your answer be something like, “it’s good practice, isn’t it?” The use of replicates in analytical procedures is commonplace but it is important to understand why you are doing it and also what the results are telling you. […]

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 […]

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 […]

Why are ‘Bio’ Test Methods so Tricky to Validate?

When it comes to validation, analytical test methods used for medicinal products based on biological molecules can be a bit ‘tricky’ to deal with. Coming up with a suitable design for the validation protocol can be quite difficult. In particular, the choice of what parameters to investigate, and the design of the associated experiments. One […]