Salicylic Acid |
Salicylic Acid | |
| OVERVIEW |
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Salicylic acid is an organic acid that has a colorless crystalline structure and is poorly soluble in water. Salicylic acid is a beta-hydroxy acid, which is a larger molecule than alpha-hydroxy acids (AHAs) and is widely used in topical formulations as a comedolytic and keratolytic agent.1,2,3,4 |
| Beta-Hydroxy Acid (AHA) |
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Beta-hydroxy acids (BHAs) are derived from plant hormones and are lipid soluble. Salicylic acid, or 2-hydroxybenzoic acid, is extracted from the bark of the willow tree, and systemic formulations provide pain relief and anti-inflammatory effects. Salicylic acid applied topically penetrates pores which contain sebum, thereby softening and removing the epithelium. Its larger molecular size limits penetration through the dermis to general circulation. Salicylic acid has been combined effectively with other ingredients for various topical applications.1,2,3 |
| History and Significance |
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Salicylic acid has been derived historically from plants, specifically the bark of the white willow tree and the meadowsweet herb. Ingestion of extracts has been reported to be effective in relieving pain, fever, and inflammation, as well as causing gastric upset.4,5 In 2000, the FDA evaluated the safety of BHAs and alpha-hydroxy acids (AHAs) as exfoliants and found that salicylic acid in cosmetics is "safe for use when formulated to avoid irritation and when formulated to avoid increased sun sensitivity."1 |
| Applications |
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Salicylic acid has been shown to be effective in dermatologic and cosmetic applications for its rapid effect as a keratolytic agent. Products containing salicylic acid include facial cleansers and antidandruff shampoos. Salicylic acid has been added in trace amounts as a food preservative and in mild antiseptics, such as mouthwashes and toothpastes. Salicylic compounds have also been synthesized for analgesics (acetylsalicylic acid or aspirin) and antipyretics (phenyl salicylate or salol). The methyl derivative of salicylic acid, methyl salicylate, is the chief constituent of oil of wintergreen.3,4 |
| CHEMISTRY |
Chemical name: 2-hydroxybenzoic acid |
| General Manufacturing Process |
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Commercial preparation involves the preparation of sodium salicylate using the Kolbe-Schmitt reaction and acidification by sulfuric acid.3 |
| Available Formulations |
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Salicylic acid is available in varying concentrations and grades, depending on intended use. Trace amounts are used as a food preservative and in over-the-counter antiseptics and antipyretics. Pharmaceutical-grade salicylic acid undergoes a complex series of filtration and purification processes. For skin applications, salicylic acid is used in concentrations ranging from 2% to 6% for hyperkeratotic and scaling conditions, with clinical use above 6% concentration in peels, suspensions, and ointments. The pH of the product can be buffered.4,5,6,7,8,9,10 |
| Biologic Activity |
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The effects of salicylic acid as a keratolytic and mild antiseptic result in rapid desquamation of keratin. Its lipid solubility is central to its ability to penetrate pores and aid in the absorption of other agents. |
| Comedolysis |
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Salicylic acid dissolves comedone formations that are blocking or restricting pore respiration and thereby is absorbed into the follicles and epidermal skin layers. Inside pores, salicylic acid neutralizes remnant acne bacteria and constricts pore diameter, forcing drainage through the pore opening to restore natural spatial structure.6,8,10 |
| Keratolysis |
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The peeling effect of salicylic acid has been demonstrated using low and moderate concentrations with a low pH to promote keratolysis, the separation of the epidermal layer from the dermis through accelerated cell loss. Salicylic acid inhibits COX-1 synthesis and affects the prostaglandin pathway by 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.5,7,8,9,10 |
| Antiseptic |
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The antiseptic effects of salicylic acid inhibit protein synthesis of the newly exposed dermal layer, providing mild antifungal benefits. |
| APPROVED INDICATIONS AND THERAPEUTIC USE |
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| Acne |
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The comedolytic and keratolytic benefits of topical salicylic acid are effective in low and moderate doses for the treatment of acne infections of varying severity, including papules, pustules, nodules, cysts. Salicylic acid has also been demonstrated to be effective in the prevention of acne on skin prone to this type of infection.6,8,12,13 Combination therapy with salicylic acid is preferred in recalcitrant cases.14 |
| Acne Scarring |
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The keratolytic effect of topical salicylic acid results in the desquamation of the epidermis, promoting dermal matrix regeneration. Combination treatment can optimize the texture and tone of treated skin.15,16 |
| Pores |
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The lipid solubility of salicylic acid is effective in penetrating sebaceous pores for subsequent dissolution of acne bacteria. The comedolytic effect of salicylic acid results in the breakdown of clogged pores to express fluid and extrude ingrown hairs, restoring pore structure to its natural state. Care should be taken in areas that present abrasions or cuts to avoid possible systemic absorption.16,17,18 |
| Seborrheic Dermatitis |
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Seborrheic dermatitis causes flaking of the skin, usually recognized on the scalp as dandruff and affecting other parts of the body such as the face and chest, as well as the creases of the arms and legs. The keratolytic properties of salicylic acid facilitate the replaning of these areas, reducing skin buildup and the oily appearance that can result from the condition.17,18,19 Etiology of the condition can be hormonal or fungal-the mild antiseptic properties of salicylic acid can provide some amelioration. Salicylic acid formulations in shampoos and cleansers for common, specific, or adjunctive treatments can be used as monotherapy or in combination with prescription steroids. |
| Xeroderma, Ichthyosis |
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The fine scales that result from xeroderma and ichythosis have been successfully treated with 6% salicylic acid gel, in conjunction with routine application of hydrating agents and medications.20,21 Chronic treatment for these conditions and diseases should be monitored by a healthcare professional, as eruptions and epithelial thickening are associated with the conditions. |
| Warts, Plantar Warts |
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Warts are abnormal noncancerous growths caused by the human papillomavirus (HPV). Outbreaks from viral infections can be treated; eruptions can also regress over time. Salicylic acid is a primary ingredient in effective over-the-counter remedies for wart removal. In a clinical setting, higher concentrations of salicylic acid are considered a nonsurgical alternative to laser surgery or cryosurgery.25 |
| CLINICAL CONSIDERATIONS | |
| Patient Instructions |
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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 |
| Duration and Frequency of Treatment |
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KAVI Salicylic Acid treatment provides healthcare professionals with flexibility in establishing the treatment plan. KAVI Salicylic 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. Following a one-month hiatus, another six- to eight-week treatment cycle may be repeated. |
| Contraindications, Warnings, Precautions |
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All products containing salicylic acid should be applied as directed. Improper use may result in acute skin irritation and inflammation. Patients using products containing salicylic acid are cautioned to use adequate sun block protection on exfoliated areas that may be exposed to sunlight. KAVI Salicylic Acid products with concentrations above 8% are contraindicated for hypersensitive skin and should be administered by trained professionals. |
| PRODUCT SELECTION FOR RESULTS |
When salicylic acid is included as part of a treatment plan, healthcare professionals can select the specific product to meet the needs of their treatment plan. Salicylic 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 |
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1. Beta Hydroxy Acids in Cosmetics. FDA. March 7, 2000. 2. Yates, R.L., and D.C. Havery, "Determination of Phenol, Resorcinol, Salicylic Acid and Alpha-Hydroxy Acids in Cosmetic Products and Salon Preparations," Journal of Cosmetic Science, vol. 50, pp. 315-325, 1999. 3. Salicylic Acid Topical. Medline Plus. September 1, 2008. Available online. 4. Balali-Mood M, Balali-Mood K. Salicylic acid. "Inter-Organization Programme for the Sound Management of Chemicals" INCHEM. August 1996. Available online. 5. White WH. "Action of Salicin Salicylic Acid and of Sodium and Lithium Salicylates", Materia Medica Pharmacy, Pharmacology and Therapeutics. P. Blakiston's Son and Co. 1911. Available online. 6. Bowe WP, Shalita AR. "Effective over-the-counter acne treatments", Semin Cutan Med Surg. Sept, 2008; 27(3):170-6. Review. Available online. 7. Steele K, Shirodaria P, O'Hare M, et al. "Monochloroacetic acid and 60% salicylic acid as a treatment for simple plantar warts: effectiveness and mode of action", Brit J Derm. July 29, 2006. 18(4):537 - 544. Available online. 8. Tsai JC, Chuang SA, Hsu MY, et al. "Distribution of salicylic acid in human stratum corneum following topical application in vivo: A comparison of six different formulations", (1999) International Journal of Pharmaceutics, 188 (2), pp. 145-153. Available online. 9. Oosterkamp HM, Neering H, Nijman SM, Dirac AM, Mooi WJ, Bernards R, Brummelkamp TR. "An evaluation of the efficacy of topical application of salicylic acid for the treatment of familial cylindromatosis", Br J Dermatol. July, 2006; 155(1):182-5. Available online. 10. "'Keratolytic' properties of benzoyl peroxide and retinoic acid resemble salicylic acid in man", Waller JM, Dreher F, Behnam S, Ford C, Lee C, Tiet T, Weinstein GD, Maibach HI. Skin Pharmacol Physiol. 2006; 19(5):283-9. Available online. 11. Herreros FO, Cintra ML, Adam RL, et al. "Remodeling of the human dermis after application of salicylate silanol", Arch Dermatol Res. Apr, 2007; 299(1):41-5. Available online. 12. Zakopoulou N, Kontochristopoulos G. "Superficial chemical peels", J Cosmet Dermatol, Sep, 2006; 5(3):246-53. Available online. 13. Kempiak SJ, Uebelhoer N. "Superficial chemical peels and microdermabrasion for acne vulgaris", Semin Cutan Med Surg. Sep, 2008; 27(3):212-20. Review. 14. "Photodynamic therapy for the treatment of acne: a pilot study", Taub AF. J Drugs Dermatol. Nov-Dec, 2004; 3(6 Suppl):S10-4. 15. "Pharmacotherapy of acne", Degitz K, Ochsendorf F. Expert Opin Pharmacother. Apr, 2008; 9(6):955-71. Review. 16. "Excellent clinical results with a new preparation for chemical peeling in acne: 30% salicylic acid in polyethylene glycol vehicle", Dainichi T, Ueda S, Imayama S, Furue M. Dermatol Surg. Jul, 2008; 34(7):891-9; discussion 899. 17. Grimes P.E. (1999). "The Safety and Efficacy of Salicylic Acid Chemical Peels in Darker Racial-ethnic Groups", Dermatologic Surgery 25: 18-22. doi:10.1046/j.1524-4725.1999.08145.x. 18. Roberts W. E. (2004). "Chemical peeling in ethnic/dark skin". Dermatologic Therapy 17 (2): 196. doi:10.1111/j.1396-0296.2004.04020.x. 19. "Effectiveness, safety, and effect on quality of life of topical salicylic acid peels for treatment of postinflammatory hyperpigmentation in dark skin", Joshi SS, Boone SL, Alam M, Yoo S, White L, Rademaker A, Helenowski I, West DP, Kundu RV. Dermatol Surg. Apr, 2009; 35(4):638-44; discussion 644. 20. "Ichthyoses - Part 1: Differential diagnosis of vulgar ichthyoses and therapeutic options", Krug M, Oji V, Traupe H, Berneburg M. J Dtsch Dermatol Ges. Jan, 2009. [Epub ahead of print] 21. "Ichthyoses - Part 2: Congenital ichthyoses", Krug M, Oji V, Traupe H, Berneburg M. J Dtsch Dermatol Ges. Jan, 2009. 22. "Treatment of severe scalp psoriasis: from the medical board of the National Psoriasis Foundation", Chan CS, Van Voorhees AS, Lebwohl MG, Korman NJ, Young M, Bebo BF Jr, Kalb RE, Hsu S. J Am Acad Dermatol. June, 2009; 60(6):962-71. Available online. 23. "Guidelines of care for the management of psoriasis and psoriatic arthritis": Section 3: "Guidelines of care for the management and treatment of psoriasis with topical therapies", Menter A, Korman NJ, Elmets CA, Feldman SR, Gelfand JM, Gordon KB, Gottlieb A, Koo JY, Lebwohl M, Lim HW, Van Voorhees AS, Beutner KR, Bhushan R; American Academy of Dermatology. J Am Acad Dermatol. Apr, 2009; 60(4):643-59. Available online. 24. "Topical tacrolimus ointment combined with 6% salicylic acid gel for plaque psoriasis treatment", Carroll CL, Clarke J, Camacho F, Balkrishnan R, Feldman SR. Arch Dermatol. Jan, 2005; 141(1):43-6. 25. "Successful treatment of florid cutaneous warts with intravenous cidofovir in an 11-year-old girl", Cusack C, Fitzgerald D, Clayton TM, Irvine AD. Pediatr Dermatol. May-Jun, 2008; 25(3):387-9. |
