Is Homosalate natural?

Homosalate is manufactured by esterifying salicylic acid, made from phenol via Kolbe-Schmitt carboxylation, with 3,3,5-trimethylcyclohexanol derived from isophorone, an acetone-based petrochemical. No commercially significant natural-feedstock route exists for this UV filter.

The industrial synthesis of Homosalate (3,3,5-trimethylcyclohexyl salicylate) primarily involves the esterification of salicylic acid with 3,3,5-trimethylcyclohexanol. This reaction is typically catalyzed by a strong acid, such as sulfuric acid or p-toluenesulfonic acid, to facilitate the formation of the ester bond.

The reaction is usually carried out under reflux conditions, with temperatures ranging from 100-150°C, depending on the specific catalyst and solvent system employed. Water, a byproduct of the esterification, is often removed azeotropically to drive the equilibrium towards product formation.

Following the esterification, the crude Homosalate undergoes purification steps. These typically include neutralization of the acid catalyst, washing to remove unreacted starting materials and byproducts, and finally, distillation or recrystallization to obtain a high-purity product suitable for cosmetic applications. The overall process is a classic example of Fischer esterification.

Alternative, less common routes might exist, but the dominant commercial production relies on the esterification of synthetically derived salicylic acid and 3,3,5-trimethylcyclohexanol, both of which trace their origins back to petrochemical feedstocks.

Homosalate is a chemical compound widely used in sunscreens and other personal care products to protect the skin from the harmful effects of ultraviolet (UV) radiation. It functions by absorbing a specific range of UV-B rays, preventing them from penetrating the skin and causing damage like sunburn and premature aging.

Chemically, Homosalate is an ester formed from salicylic acid and an alcohol called 3,3,5-trimethylcyclohexanol. Both of these starting materials are typically produced through complex chemical processes that begin with raw materials derived from petroleum. Therefore, according to the ISO 16128 standard for natural origin ingredients, Homosalate is classified as having zero natural origin content.

CosIng definition: Homosalate is the substituted phenolic compound that conforms to the formula: