Step By Step Ensuring Effective Drug Stability Testing


Stability testing illustrates how the quality of a drug substance or drug product could be affected by light, temperature, humidity and other environmental factors, and is used to demonstrate shelf life in recommended storage conditions. Studies to evaluate some physical, chemical, biological, and microbiological attributes that may change during storage can be complicated and costly.This report discusses the regulatory expectations and guidance documents for drug equilibrium testing, and offers practical approaches to stability testing of both small- and – large-molecule drug materials, such as a risk-based method of testing for different phases of the product lifecycle. Special considerations for assessing the impact that temperature trips, vibration and other environmental factors might have on the drug product during transport are also included.

Virtually all regulatory requirements for drug Stability Testing are clearly described in guidelines. Tests within good manufacturing practice GMP regulations for certain product applications e.g., in-use stabilities, are summarized, and there are far more detailed and specific recommendations which fall under best practices. GMP regulations are extremely similar around the world, and demand a pharmaceutical product to have an expiration date, determined by appropriate stability testing. They also need a written stability testing program that defines sample sizes and test intervals based on statistical standards; controlled storage requirements; supported and specific test methods; and that a decent number of drug manufacturing batches are tested. Stability testing of the product in its advertised container or closed is also required.

In investigational programs, regulations require information to be filed supporting drug substance and drug product stability during pre-clinical and clinical testing, and information should be filed consistent with the period of analysis.Depending on new drug applications, admissions for approval by the regulatory authorities are expected to include data from stability studies conducted on both the drug substance and drug product, in support of their item expiration date. For abbreviated applications, like those for new generic drugs, stability data must be included on the particular batch es used to run the pivotal bioavailability or bioequivalence study. The data must demonstrate that the generic has pharmaceutical equivalence to the branded product by using a similar stability profile.