Stability: Back to the Basics - Part I

Back2Basics_Blog1.jpgPart I: The Importance of Stability in the Evaluation of Quality Attributes of Pharmaceutical Drug Products

In this five-part blog series, Alcami subject matter experts, Russell Crothers and Adam Keisker, go “back to the basics” to examine the importance of stability in pharmaceuticals, beginning with quality attributes.

Exactly how important is stability testing in the life of the active pharmaceutical ingredient (API) or drug product?

The quality attributes that everyone strives for are safety, product efficacy and integrity, appropriate storage conditions, and shelf life.

The US Pharmacopeia (USP) defines “stability” as the extent to which a product retains, within specific limits, and throughout its period of storage and use (i.e., its shelf life), the same properties and characteristics that it possessed at the time of its manufacture <USP1191>. The purpose of stability is to examine how the critical quality attributes of a drug substance vary with time under different environmental factors. These environmental factors include temperature, humidity, and light in order to establish a retest period (i.e. shelf life) for the drug substance along with the recommended storage conditions. This process ensures that no physical, chemical, or microbiological changes affect the quality and integrity of the final products.

These storage conditions and shelf life in API and drug products directly take into account the intended markets based on the climate conditions. Derived from the mean kinetic temperature of any part of the world, four climatic zones have been distinguished for stability testing worldwide: Zone I-IV <ICH Q1A-Q1F>.


These climatic zones are simulated in chambers that involve temperature, humidity, and light under the guidance of International Conference on Harmonisation (ICH) and U.S Food and Drug Administration (FDA) guidelines.

Through stability testing, pharmaceutical companies can help ensure that the product has the most suitable packaging or container closure for storage and distribution. And with the right storage and distribution methods in place, the quality of API and drug products is safeguarded.

Thank you for your interest in learning more about stability. Stay tuned for the next post in this series:  Part II: The Impact of Stability on the Safety of API and Drug Products.

About the Authors

Russell Crothers is a leading authority for the generation, review, and edits of stability protocols at Alcami's St Louis site. He is responsible for the execution and management of the commercial and clinical development products for stability and maintains compliance with both ongoing and new regulatory requirements. His work as Lab Materials Support IV here is best showcased in his ability to streamline and digitize processes resulting in more efficient, precise stability services. He is the Power of Attorney for Controlled Substances at the Alcami St. Louis site. Russell graduated from Greenville College with a B.A. in Biology and has since joined the Alcami team in 2015.

Richard “Adam” Keisker is the Lead Sample Control Unit (SCU) Coordinator for Alcami’s St. Louis site. He oversees the coordination of analytical samples in a pharmaceutical testing environment, specifically the stability programs protocol approvals, storage, sets and release for analytical testing. Adam graduated from Lindenwood University with a B.A. in Chemistry with a concentration in forensics.


Topics: Stability Blogs