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Clinical Research
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pH buffered versus pH balanced: what does this mean for skin cleansers and the skinÕs acid mantle? David Brett, BS, BS, MS, Smith & Nephew, Largo, FL One of the primary functions of the skin is protection. It does this by acting as a buffer against trauma due to its inherent elastic properties. Additionally, the skin serves as the first line of defense against invading pathogens or antigens. Lactic acid and various amino acids (from sweat and cornification) and free fatty acids (from sebum) are chemical compounds which help retain water within the stratum corneum. They also help maintain the acidic pH of the skin. The Stratum Corneum (outer most layer) is composed of sebum and corneocytes which create a thin surface film (acid mantle), that is slightly acidic (pH range of 4.5 -5.7). This acidic environment is essential to maintain the production of the proteins and lipids which are essential to the skin. Compromising the acid mantle results in an increase of skin surface pH. If the acid mantle becomes disrupted or damaged, or loses its acidity, the skin becomes more prone to damage, infection and disease. This study investigates pH fluctuations & effects on the acid mantle of a variety of skin cleanser formulations. ÒBuffering capacityÓ was determined via titration w/ acid & base. Effects on the acid mantle were investigated via a skin pH meter. It was found that pH buffered cleansers have a greater buffering capacity than do pH balanced. Also, some formations claiming ÒpH balancedÓ are actually pH buffered due to certain formulation components. The acid mantle was altered by formulations w/ pHs buffered at ~ 5.5 than pH balanced formulations of other pHs. Yosipovitch. The importance of pH. Skin Care March/April 04 Ffliger. The epidermal skin barrier: implications for the wound care practitioner, part I. Adv Skin Wound Care. 2004;17(8):41 Gray M. Preventing and managing perineal dermatitis. JWOCN. 2004:52. |
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