Antiaging, antiacne, depigmenting
Important Chemical Components:
Natural retinoids: The major naturally-occurring retinoids are tretinoin (all-trans retinoic acid, also known simply as retinoic acid), the stereoisomers of tretinoin [isotretinoin (13-cis-retinoic acid) and alitretinoin (9-cis-retinoic acid)], retinol, retinaldehyde, and retinol esters (retinyl acetate, retinyl palmitate, retinyl propionate).
Synthetic retinoids: The retinoids that have been designed in the laboratory to increase stability are tazarotene (molecular formula: C21H21NO2S), adapalene (molecular formula: C28H28O3), and retinyl retinoate (an ester of retinoic acid and all-trans retinol).
Retinoids are natural and synthetic derivatives of vitamin A (also known as all-trans retinol). As ingredients in skin therapy, these products are laboratory made.
Personal Care Category:
Recommended for the following Baumann Skin Types:
DRNW, DRPT, DRPW, DSNW, DSPT, DSPW, ORNW, ORPW, ORPT, OSPW, OSNW, and OSPT
Vitamin A is found naturally in the skin and other parts of the body and is obtained through the diet from carotenoid-containing foods, such as sweet potatoes, carrots, dark green leafy vegetables, tomatoes, squash, apricots, cantaloupe, red pepper, and tropical fruits (e.g., mangoes and papayas).1,2 Like β-carotene, lutein, lycopene, and other carotenoids, retinoids are derived from vitamin A (all-trans retinol). The retinoid family includes natural (e.g., tretinoin, isotretinoin, alitretinoin, retinol, and retinaldehyde) and synthetic (e.g., tazarotene, adapalene, and retinyl retinoate) forms. Retinol and retinyl esters represent 99 percent of cutaneous retinoids naturally present in the skin.3 The retinoids used in prescription products and over-the-counter (OTC) skin care formulations are synthesized in laboratories.
Retinoids have demonstrated salutary benefits in the treatment of various cutanous conditions, including acne, psoriasis, ichthyosis, and photoaging. In fact, retinoid efficacy has been reported in more than 125 distinct dermatologic disorders.4 Two prescription retinoids, tretinoin (retinoic acid) and tazarotene, have been approved by the United States Food and Drug Administration (FDA) for use in the treatment of photoaging, although isotretinoin (the 13-cis isomer of tretinoin), and several synthetic retinoids are deployed for therapeutic applications (Table 83-1).3 In addition, retinol, though it has not been approved by the FDA to treat photoaging or included among the FDA monograph ingredients for that purpose, is known to impart antiaging activity. The retinoids used in effective skin care products include retinoic acid (tretinoin), retinol, retinaldehyde, adapalene, or tazarotene. Retinyl esters such as retinyl palmitate (RP) are used in several OTC formulations, but the efficacy is questionable because penetration rates are minimal.
TABLE 83-1Pros and Cons of Retinoids ||Download (.pdf) TABLE 83-1 Pros and Cons of Retinoids
Variety of products
Excellent research on efficacy, with significant evidence from randomized controlled trials
Difficult to formulate
Irritation lessens with time
Many products do not work because of packaging and ...