Essential Ingredients has spent years studying benzoyl peroxide in acne applications to launch a non-irritating form of the ingredient. Curoxyl BP 42 USP Gel is a patent pending aqueous-based, micronized benzoyl peroxide dispersion (40%) that complies with the U.S. Food and Drug Administration's Benzoyl Peroxide Gel monograph.
The average human pore is 50 micron, and typical BPO particles are larger than the pore itself. Curoxyl BPO particles are less than 10 micron to allow it to penetrate pores and attack P. acnes bacteria. The consistently small particle size of Curoxyl is also the key to this lack of irritation.
Unlike the powder form of BPO, Curoxyl is in a gel form, so no milling is needed prior to use in a formula. Although the micronized benzoyl peroxide is available only in USP grade dispersion, it is priced competitively with other non-USP grades. The benzoyl peroxide gel is odor free and compatible with most cosmetic oils, waxes, glycols and PEGs. It can be the starting point for topically applied anti-acne creams, anti-acne wipes, face and body washes, cleansers and medicated pet shampoo formulations.
The ingredient has been shown in a semi-occlusive RIPT study of 100 participants to be both a non-primary irritant and a non-primary sensitizer to human skin when used at an active benzoyl peroxide level of 10%. These results were confirmed in a 12-day cumulative irritation study of 25 subjects. It was compared to a larger particle size form of benzoyl peroxide on a group of Super Stinger subjects (those with very sensitive skin). Each formula contained a 10% active level of benzoyl peroxide. In this double-blind, clinical trial of Super Stinger subjects, Curoxyl 42 was shown to be 37% less irritating than the control benzoyl peroxide particles which average 10x larger than those in Curoxyl.