The ability of an active pharmaceutical ingredient (API) or pharmaceutical product to remain durable when exposed to daylight or ambient light is called photostability.Photostability and stress testing detects the formation of degradation products by subjecting the finished product or a placebo to photolysis, which is the degradation process induced by light.
The photostability study can be applied to the pharmaceutical product directly or in the form of an aqueous solution. Since light radiation is ubiquitous and unavoidable, it is necessary to test both the pharmaceutical product and the packaging for long-term light exposure. If the pharmaceutical product contains substances that can undergo changes induced by light radiation, these changes can have various adverse effects, including reduced drug efficacy and a risk to patient health. For this reason, by approaching our studies about the pharmaceutical product step by step, starting with testing the drug product fully exposed to degradation conditions and progressing to the primary packaged product and, if necessary, the secondary packaged product.
At the end of the exposure period, the samples are checked for any changes in their physical properties (such as the appearance, clarity or color of the solution).
The stress study examines the durability of a chemical or pharmaceutical product under harsh conditions. In this context, “stress” refers to any physical or environmental condition a product may experience that may cause chemical change.
Important findings from the stress study are as follows;
- Identify possible by-products and degradation pathways
- Determination of molecular stability
- Validation of analytical techniques for the evaluation of chemical stability
- Learning about drug storage and packaging
Stress studies can be done for any chemical, but they are very important in the development of pharmaceuticals. The active pharmaceutical ingredients are precisely formulated to achieve a specific pharmaceutical effect. Chemical changes that may occur in the drug product can reduce its effectiveness or cause adverse side effects. Therefore, stress and photostability studies should be performed specifically for pharmaceutical drug products and APIs.
With the help of these tests, it is possible to determine the excipients to be used during product formulation, to optimize the formulation and to carry out stability-indicated method development studies.