Stearic acid is a fatty acid that is naturally occurring in animal fats such as pork fat. It is a popular additive in soaps, lotions and hair care products. Its lubrication, softening and emulsification properties make it a good choice for many cosmetic applications.
In suppositories, it has been found to be particularly effective as a stabilizer and thickener. It can also contribute a pearly finish to lubricants and is used as an emulsifier for shampoos, shaving creams, soaps and many other daily use cosmetic products.
The fatty acid can be manufactured from the splitting of the stearin fraction of a vegetable oil (palm or coconut) or an animal fat such as butter fat. It is a white, waxy solid that melts at 156degF (69degC) and is odorless and tasteless.
It is a stable and durable ingredient that can be stored for years with minimal damage. It is also a nontoxic substance that doesn’t heat spontaneously and can be used safely in a variety of cosmetic applications.
Besides its primary uses in cosmetics, stearic acid is a common ingredient in chewing gum base and is used to produce a hardener for candles and other products that may be exposed to extreme heat. It also has a number of medical and industrial applications including modifying the melting point of petroleum-based waxes, as well as serving as an anti-oxidant and reducing the amount of cholesterol absorbed by the body.
When using stearic acid in suppositories, it is important to follow the manufacturer’s instructions closely. It is best not to use this product near the eyes or inner nose, and it should never be applied to sensitive areas of the skin. If irritation occurs, discontinue use and see a doctor or dermatologist immediately for a health assessment and appropriate remedial action.