Glycolic Acid |
Glycolic Acid | |
OVERVIEW |
Glycolic acid is a small-molecule hydroacetic acid that is colorless, odorless and hydroscopic. These properties make glycolic acid a suitable ingredient for keratolysis (exfoliation) and anti-aging applications (stimulation of tissue production and hydration).1 Glycolic acid is also water soluble, making it versatile for dermatologic and cosmetic formulations. |
Alpha-Hydroxy Acid (AHA) |
Alpha-hydroxy acids (AHA's or hydroacetic acids) were initially derived from fruit, sugar cane, and milk. Common AHA's include glycolic, citric, and lactic acid; all AHA's are water soluble and lack systemic toxicity.1 As the shortest-chain AHA molecule, glycolic acid has been shown to be an effective organic compound in penetrating dermal layers. |
History and Significance |
In the 1970's the efficacy of AHA's were introduced to decrease corneocyte adhesion and stimulate epidermolysis on psoriatic lesions. This provided dermatologists with alternatives for chemical peeling agents such as trichloroacetic acid and phenol.1 In 1992, cosmetic products containing AHA's were commercially available2,3 and FDA-approved laboratories such as KAVI manufacture AHA's to precise specifications and purity.4 |
Applications |
Concentrations of glycolic acid have been shown to be effective in dermatologic and cosmetic applications combining the mechanism of dermal penetration and hydroscopic actions with its water-soluble properties. Products containing glycolic acid include but are not limited to peels, facial washes, and moisturizers. The clinical utility of glycolic acid formulations focuses on both its keratolytic and rejuvenative effects in the treatment of acne scarring, dyspigmentation, and keratosis. |
CHEMISTRY |
Chemical name: 2-hydroxyethanoic acid Molecular formula: carboxylic acid substituted with a hydroxy group on the adjacent carbon: C2H4O3 |
General Manufacturing Process |
Glycolic acid is derived from sugar cane and sugar beets. It has also been commercially synthesized by direct reaction of chloroacetic acid with sodium hydroxide and reacidification: ClCH2CO2H + NaOH → HOCH2CO2H + NaCl Manufacturers can utilize a fermentation-based biochemical process to synthesize varying grades of glycolic acid.5 It is supplied in either liquid or crystalline form. |
Available Formulations |
Glycolic acid is available in varying concentrations and grades, depending on intended use. Industrial-grade glycolic acid used at greater than 70% concentrations is considered nonvolatile, hazardous material for rust removal and textiles. Pharmaceutical-grade glycolic acid undergoes a complex series of filtration and purification processes. For skin applications, glycolic acid is used in concentrations ≤70%, with clinical use above 50% concentration. The pH of the product can be buffered. |
Biologic Activity |
The effects of glycolic acid for keratolysis, moisturization, and rejuvenation result from its biologic effect on dermal matrix degradation as well as collagen and elastin synthesis. |
Keratolysis |
The peeling effect of glycolic acid has been demonstrated using high-concentration, low-pH formulations to promote keratolysis, the separation of the epidermal layer from the dermis through accelerated cell loss. The mechanism behind this effect is a weakening of the intercellular corneocyte bonds that disrupts the adhesion of corneocytes in the lower stratum corneum, causing a separation of the bulky upper layer from the newly formed lower layer.1,5,6 |
Moisturization |
The hydroscopic property of glycolic acid promotes moisture retention in the tissues by stimulating collagen synthesis and the synthesis of dermal glycosaminoglycans.6 Moisturizing effects are further enhanced with the combination of glycolic acid to hydrophilic lotions, gels, and washes. |
Rejuvenation |
The cumulative effects of keratolysis along with the hydroscopic and penetrating properties of glycolic acid produce changes in skin surface texture and tone, smoothing fine lines and wrinkles.1,5 The application of glycolic acid has been shown to directly accelerate collagen synthesis through fibroblasts and stimulate IL-1 alpha which is a primary mediator for matrix degradation. Keratinocyte-released cytokines modulate dermal matrix degradation and collagen synthesis.6 |
APPROVED INDICATIONS AND THERAPEUTIC USE |
Glycolic acid has been shown to be effective in minimizing acne scars and stimulating dermal regeneration. Glycolic acid is effective in enhancing the effects of other products to reduce acne flare ups and infection.8,11 |
Facial Rejuvenation, Wrinkles |
Glycolic acid reduces the appearance of fine lines and wrinkles and improves the skin's tone and texture. It is effective as an adjunct to other techniques.9 |
Hyperpigmentation |
The peeling effect and inherent hydroscopic properties of glycolic acid can be employed to achieve sustained results in the treatment of age spots5,12, photodamage, melasma, and lentigines. |
Melasma |
Melasma is facial hyperpigmentation that is often manifested among pregnant women due to wide shifts in hormones. Glycolic acid was studied to be an effective and safe therapy alone or as part of combination treatment to reduce the Melasma Area Severity Index (MASI).7,15 |
Lentigines |
Lentigines are characterized by uneven pigmentation of the skin. While glycolic acid and AHA's are considered to increase sensitivity to ultraviolet rays, it has been used effectively to improve dermal regeneration and reduce pigmentation variance.15 |
Keratosis |
The penetration properties of glycolic acid to promote dermal rejuvenation and collagen synthesis are effective in treating keratoses. |
Actinic Keratosis |
Glycolic acid improves skin surfacing and promotes regeneration in the stratum corneum which may reduce the progression of atypical squamous cells characteristic of premalignant lesions to squamous cell carcinoma.16,17 |
Hyperkeratosis |
Areas of the body can be treated with glycolic acid to reduce thickening and hyperpigmentation.1,5 Moisturizers containing glycolic acid improve maintenance of skin tone. |
Seborrheic Keratosis |
While cryosurgery is more effective in removing noncancerous lesions, glycolic acid has been considered the nonsurgical alternative for surface removal of seborrheic keratosis.15 |
Keratosis Pilaris (KP) |
Keratosis pilaris, or follicular keratosis, is a genetic condition whereby keratinized follicles appear in areas of the body as rough, dry bumps. While there is no cure for this mostly harmless condition, KP can be unsightly. Continuous treatment using prescription medication and creams is effective. Regular application with glycolic acid can exfoliate excess tissue and promote dermal rejuvenation to enhance the skin's texture and tone. |
CLINICAL CONSIDERATIONS | |
Patient Instructions |
KAVI provides recommended instructions for all products for optimal results. Healthcare professionals should provide specific patient instructions based on the therapy (single or combination) and desired results. Instructions for use may be found at the following locations: Instructions for skin care professionals Instructions for physicians |
Duration and Frequency of Treatment |
KAVI Glycolic Acid treatment provides healthcare professionals with flexibility in establishing the treatment plan. KAVI Glycolic Acid peels may be repeated weekly until the desired results are achieved. After an initial six to eight weekly applications, diminished results may be observed, indicating a resting phase (rejuvenation cycle). During the resting phase, the skin will continue to regenerate. Following a one-month rejuvenation cycle, another six- to eight-week treatment cycle may be repeated. |
Contraindications, Warnings, Precautions |
All products containing glycolic acid should be applied as directed. Improper use may result in acute skin irritation and inflammation. Patients using products containing glycolic acid are cautioned to use adequate sun block protection on exfoliated areas that may be exposed to sunlight. KAVI Glycolic Acid products with concentrations above 20% are contraindicated for hypersensitive skin and should be administered by trained professionals.13 |
PRODUCT SELECTION FOR RESULTS |
When glycolic acid is included as part of a treatment plan, healthcare professionals can select the specific product to meet the needs of their treatment plan. Glycolic acid products provide healthcare professionals the added flexibility of customizing post-treatment plans to include lifestyle and long-term goals. Factors to consider are outlined in the table below.
KAVI Products have been developed to provide professionals with a line of high-quality products that can be configured for your treatment needs. Additional information for skin care professionals Additional information for physicians Comparative data on glycolic acid and salicylic acid |
REFERENCES |
1. Scheinberg R. "Alpha-hydroxy acids for skin rejuvenation" West J Med. April, 1994; 160(4): 366-367 2. Kurtzweil P. "Alpha hydroxy acids for skin care: smooth sailing or rough seas?" FDA. May, 1999. Accessed May 21, 2009. 3. Alpha Hydroxy Acids. USFDA CFSAN. October 27, 2008. Accessed May 21, 2009. 4. Data on File. San Francisco, CA: KAVI Laboratories; 2009. 5. Bernstein EF, Lee J, Brown DB, et al. "Glycolic acid treatment increases type I collagen mRNA and hyaluronic acid content of human skin" Dermatol Surg. 2001;27:429-433. 6. Okano Y, Abe Y, Masaki H, et al. "Biological effects of glycolic acid on dermal matrix metabolism mediated by dermal fibroblasts and epidermal keratinocytes" Exp Dermatol. 2003;12 Suppl 2:57-63. 7. Rendon M, Cardona LM, Bussear EW, et al. "Successful treatment of moderate to severe melasma with triple-combination cream and glycolic acid peels: a pilot study" Cutis. 2008 Nov;82(5):372-8. Available online. Accessed May 21, 2009. 8. Kempiak SJ, Uebelhoer N. "Superficial chemical peels and microdermabrasion for acne vulgaris" Semin Cutan Med Surg. Sept, 2008; 27(3):212-20. Available online. Accessed May 21, 2009. 9. Briden E, Jacobsen E, Johnson C. "Combining superficial glycolic acid (alpha-hydroxy acid) peels with microdermabrasion to maximize treatment results and patient satisfaction" Cutis. Jan, 2007; 79(1 Suppl Combining):13-6. Available online. Accessed May 21, 2009. 10. Effron C, Briden ME, Green BA. "Enhancing cosmetic outcomes by combining superficial glycolic acid (alpha-hydroxy acid) peels with nonablative lasers, intense pulsed light, and trichloroacetic acid peels" Cutis. Jan, 2007; 79(1 Suppl Combining):4-8. Review. Available online. Accessed May 21, 2009. 11. Dreno B, Katsambas A, Pelfini C, et al. "Combined 0.1% retinaldehyde/ 6% glycolic acid cream in prophylaxis and treatment of acne scarring" Dermatology. 2007; 214(3):260-7. Available online. Accessed May 21, 2009. 12. "Guidance for Industry: Labeling for Topically Applied Cosmetic Products Containing Alpha Hydroxy Acids as Ingredients" FDA. January 10, 2005. Accessed May 21, 2009. 13. "Alpha hydroxy acids in cosmetics" FDA. July 3, 1997. Accessed May 21, 2009. 14. Erbil H, Sezer E, Tastan B, et al. "Efficacy and safety of serial glycolic acid peels and a topical regimen in the treatment of recalcitrant melasma" J Dermatol. Jan, 2007; 34(1):25-30. 15. Sezer E, Erbil H, Kurumlu Z, et al. "A comparative study of focal medium-depth chemical peel versus cryosurgery for the treatment of solar lentigo" Eur J Dermatol. Jan-Feb, 2007; 17(1):26-9. 16. Burns RL, Prevost-Blank PL, Lawry MA, et al. "Glycolic acid peels for postinflammatory hyperpigmentation in black patients, a comparative study" Dermatol Surg. 1997; 23:171-175. 17. Hantash BM, Stewart DB, Cooper ZA, et al. "Facial Resurfacing for Nonmelanoma Skin Cancer Prophylaxis" Arch Dermatol. 2006; 142(8):976-982. |