Important Chemical Components:
Retinol: A form of vitamin A also known as (2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohex-1-enyl)nona-2,4,6,8-tetraen-1-ol. Its molecular formula is C20H30O.
Retinoic acid: A metabolite of vitamin A also known as all-trans retinoic acid and (2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohexen-1-yl)nona-2,4,6,8-tetraenoic acid. Its molecular formula is C20H28O2.
Retinyl palmitate: Also known as retinol palmitate, vitamin A palmitate and [(2E,4E,6E,8E)-3,7-Dimethyl-9-(2,6,6-trimethyl-1-cyclohexenyl)nona-2,4,6,8-tetraenyl] hexadecanoate. Its molecular formula is C36H60O2.
Retinol occurs in nature as vitamin A, but the retinol found in personal care products is laboratory made.
Personal Care Category:
BST Treatable with this Ingredient:
DRPW, DRNW, DSNT, DSPT, DSNW, DSPW, ORNW, ORPW, OSNT, OSNW, OSPT, and OSPW. These are the preferred ingredients for subtype S1 sensitive skin (acne).
All of the natural and synthetic derivatives of vitamin A are included in a family of compounds known as the retinoids. Many prescription retinoids, including tretinoin, adapalene, and tazarotene, have been approved by the United States Food and Drug Administration (FDA) for use in treating acne. While retinol is not FDA approved for use in acne and is not included in the FDA monograph ingredients that can be used for the disorder it certainly exerts antiacne effects. Although vitamin A is naturally occurring and is found in foods that contain carotenoids such as carrots, the retinols used in over-the-counter (OTC) skin care products are laboratory made. Putting carrots, carrot extract, or β-carotene on the skin would not be sufficient because of the lack of skin penetration of the ingredients. For this reason, effective skin care products use retinoic acid (tretinoin), retinol, adapalene, or tazarotene as the form of retinoid. Some skin care products use retinyl esters such as retinyl palmitate (RP), but the efficacy is questionable because penetration rates are minimal. Carotenoids, a large family of secondary metabolic products that provide pigment to the many fruits and vegetables in which they are found, are precursors to vitamin A. Although some carotenoids (such as β-carotene, lycopene, lutein, astaxanthin, and zeaxanthin) are known to confer antioxidant activity and photoprotective effects,1,2 a discussion of these compounds is beyond the scope of this text.
In 1937, the Nobel Prize was awarded to Karrer et al. for determining the structure of retinol.3 Retinol was successfully synthesized in 1943 and soon thereafter became commercially available. Since that time, the number of retinoid formulations has proliferated, now numbering over 2,500 products including prescription and nonprescription preparations. Prescription topical retinoids, including tretinoin (Retin A), tazarotene (Tazorac), and adapalene (Differin), have been widely used for decades to treat moderate acne based on their efficacy in reducing comedogenesis,4,5 and normalizing keratinization.6–9 The two most common retinoids found in OTC products are retinol ...