Cosmetic and personal care products may be exposed to many different conditions throughout their life cycle. When considering a stability testing regimen, it is necessary to try to replicate the conditions that they are most likely to experience during their transport, storage and use.
When we go outside and our bodies are exposed to the sun and its UV rays, we have learned how the UV light can cause significant damage to our bodies. Cosmetic products and packaging can also be damaged by UV light. Exposure to light may significantly alter the formulation and lead to degradation of the product ingredients and unpleasant changes in the packaging.
When a product is displayed on a shelf for sale, it may face a long duration of lighting which can affect the product's color, odor and overall appearance. Cosmetic products whose packaging allows the product to be exposed to light should undergo photostability testing. Photostability testing consists of products in their actual packaging and in glass as a control being placed under controlled light sources with broad spectrum output to account for variations in lighting that they may encounter. The samples are compared with a sample of the product that was not exposed to light to determine if significant changes occurred that were caused by the lighting.
Photostability testing is an important part of any stability testing regimen to ensure that your cosmetic and personal care products and their packages will hold up through out their shelf-life.