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Science

Introduction

PHA2 with Chamomile Extract contains a 2% concentration of gluconolactone, retaining similar functions found in AHA and BHA chemical exfoliants, but formulated to be gentler and less irritating, which is a great alternative for those with sensitive skin. Its primary function is to modulate skin keratinisation for better absorption of serums, lotions, and moisturizers and evening out the skin texture. It also stimulates cellular regeneration and restores stratum corneum function. 

Mechanism

One of the more frequently encountered skin problems is xerosis, commonly known as dry skin. It can be improved temporarily with the application of common water-retaining substances such as glycerin and propylene glycol. However, the condition of dry skin persists because skin functions such as corneocyte production, desquamation, and water-retaining capacity are not performing optimally. Topical use of PHA formulations on dry skin restores the stratum corneum function and epidermis, reducing transepidermal water loss and allowing more water to be retained in the skin.1-2 Gluconolactone is a naturally occurring component of the skin. The molecule is larger than general AHAs, facilitating a more gradual penetration into the skin, thus minimizing irritation. It converts to gluconic acid after penetrating into the epidermis, disrupting the intercellular cohesiveness in the stratum corneum, resulting in normal epidermal keratinization. Studies have shown topical application of PHAs for extended periods, substantially increases dermal thickness as a result of increased amounts of hyaluronic acid and other glycosaminoglycans as well as with qualitative improvements in collagen fibers and quality of elastic fibers. The effect of increased skin thickness persists for months even after ceasing topical application.3-8

Formulator’s Notes

An optimal amount of surfactant is used to lower the surface tension between the skin surface barrier and the product, allowing active ingredients to penetrate the stratum corneum. PHA, as the first step of skincare routine, is a gentler alternative that removes dead skin cells, facilitating the penetration of other skincare products used subsequently. 

1. Rizer R, Turcott A, Edison B, et al. An evaluation of the tolerance profile of a complete line of gluconolactone-containing skin care formulations in atopic individuals. Skin Aging 2001;9(suppl):18-21. 17.
2. Rizer R, Turcott A, Edison B, et al. An evaluation of the tolerance profile of gluconolactone-containing skin care formulations in individuals with rosacea. Skin Aging 2001;9(suppl):22-5.
3. Ditre CM, Griffin TD, Murphy GF, et al. Effects of α-hydroxy acids on photoaged skin: a pilot clinical, histologic, and ultrastructural study. J Am Acad Dermatol 1996;34:187-95.
4. Bernstein EF, Underhill CB, Lakkakorpi J, et al. Citric acid increases viable epidermal thickness and glycosaminoglycan content of sundamaged skin. Dermatol Surg 1997;23:689-94.
5. Van Scott EJ, Yu RJ. Actions of alpha hydroxy acids on skin compartments. J Geriatr Dermatol 1995;3(suppl A):19-24. 20.
6. Kim SJ, Park JH, Kim DH, et al. Increased in vivo collagen synthesis and in vitro cell proliferative effect of glycolic acid. Dermatol Surg 1998;24:1054-8. 21.
7. 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;27:1-5. 22.
8. Green BA, Edison BL, Wildnauer RH, et al. Lactobionic acid and gluconolactone: PHAs for photoaged skin. Cosmet Dermatol 2001;9: 24-8.