Shelf life and PaO in cosmetic products: possible analytical approaches
The label of cosmetic products needs the indication of time stability: shelf life or PaO (Period after Opening). This a tool for the consumer to know the period in which he can use the product in total safety. To maintain the safety level acceptable over time, the product must be packaged in suitable packaging and it must remain stable from a microbiological and chemical-physical viewpoint
In this article we will introduce a minireview about the stability of cosmetic products, attempting to trace a possible analytical approach for its evaluation.
At this time, no scientific method exists which can unequivocally establish the stability of a cosmetic product. And we should not be particularly astonished by this. We are talking about a truly vast sector, with very diverse formulations:from a polymer resin-based nail varnish to an aqueous emulsion with surface-active agents for common body cleansers, or a silicone-based body oil or a normal toothpaste.
In this context the consumer plays a key role. In our evaluations, normal or reasonably predictable conditions of use of the product should be considered first of all. We must try to see things from the end user’s perspective and understand how the product will be handled, with what daily frequency, and how it will be stored.It’s important to consider whether the product is intended for a single user or several people, perhaps for the entire family.
Any product that is applied on the external surfaces of the human body whose action is aimed at the uppermost layer of the dermis, to improve the aesthetic appearance, maintain in good condition, protect, cleanse and perfume, is a cosmetic. But a cosmetic product is also a f ...