Photostability is the process of exposing a product to a specified Lux (lx) of artificial UV light which simulates real-world environments. This can include direct sunlight, sunlight through a window, or simulated office lighting. The purpose of this testing is to demonstrate that degradation to the drug product or drug formulation has not occurred and confirm a light-stable packaging system that adequately protects the product throughout its intended shelf life.
For pharmaceuticals, the primary regulatory guidance is ICH Q1B: Stability Testing—Photostability Testing of New Drug Substances and Products. This guidance describes a tiered approach to photostability evaluation, beginning with the drug substance and progressing through the immediate container closure system and, when appropriate, the final marketing package. At each stage, the product is evaluated for unacceptable changes in quality. If light-related degradation is observed, changes to the formulation, manufacturing process, or packaging may be needed.
Depending on the product and study objectives, photostability studies can include, visual inspection, functional and mechanical testing, package integrity testing, container closure integrity (CCIT), and dimensional analysis. DDL can assist customers with these studies in our FDA Registered Laboratory.
As part of DDL’s GMP testing services, photostability studies help confirm that pharmaceutical products remain safe, effective, and within quality specifications under expected light exposure conditions. These studies support formulation development, packaging selection, shelf-life justification, and regulatory submissions.
Contact us for more information or to talk with an engineer.
