What is a stability indicating method?

What is a stability indicating method?

A stability indicating method is a quantitative test method that can detect possible degradants and impurities of drug substance (API) and drug products, normally using High Performance Liquid Chromatography (HPLC). Stability information is needed for regulatory submissions such as IND (Investigational New Drug Application) and NDA (New Drug Applications) and to set expiration dates for the API or drug product.

 

Before performing stability studies, a stability indicating method is necessary so that any possible degradants generated during storage conditions (such as 5°C, 25°C/60%RH and 40°C/75%RH) can be separated, detected, and quantitated.

 

The method should be sensitive to the reportable impurity level. LOQ (limit of quantitation), which is typically 0.05% of Label Claim, should be established in the method, and the method should be linear from LOQ to typically up to 150% of the nominal standard (std) concentration.

 

The forced degradation studies are another very important part of the validation of the stability indicating method. In forced degradation studies, samples are stored under extreme conditions (acid, base, peroxide, heat, light, humidity etc) in order to rapidly screen drug product stabilities.

Stability-indicating methods are traditionally performed using gradient elution, in order to ensure that degradants of various chemical compositions are all detected.