Lightening efficacy enhanced via polymeric technology

But there are also needs in other markets for use in anti-ageing products or treatments against uneven pigmentation, like age spots and post-inflammatory hyperpigmentation, a common problem seen in people with dark skin. Cosmetic products that lighten, brighten, or whiten skin are widely used for reduction of natural skin pigmentation but also to accomplish a matching, consistent tone or to influence pigmentation disorders such as melasma, freckles, sun or age spots, and scarring lesions. Several active ingredients have shown to be effective in skin whitening, although some have shown to be toxic or, at least, have questionable safety profiles, e.g. hydroquinone. Some commonly used whitening agents like arbutin, kojic acid, and ascorbic acid derivatives have shown interesting efficacy in a variety of hyperpigmentary disorders. As significantly lightening the skin is a difficult task, systems which can optimise delivery, therefore enhancing bioavailability, are of particular interest in these cases.

Mode of action

Especially for hydrophilic actives, the appropriate delivery system is essential. The ideal delivery system is supposed to optimise delivery, enhance efficacy, reduce irritation through controlled delivery, and improve activity at reduced concentration. Lexorez TL-8 (INCI: Trimethylpentanediol/Adipic Acid Copolymer) supports topical delivery of active ingredients. It can be used to facilitate high loading levels of actives at moderate costs. Lexorez TL-8 (now referred to by its INCI name) is based on polymeric liquid reservoir technology and controls diffusion of actives into the epidermis through partitioning. Due to its low molecular weight (800 MW) it facilitates uniform distribution of actives throughout the stratum corneum for an extended period of time. The active will slowly penetrate into the viable epidermis. For the penetration of active ingredients, the intercellular route is essential. The intercellular matrix consists of lipids so hydrophilic active ingredients do not normally penetrate efficiently through this route. Trimethylpentanediol/Adipic Acid Copolymer facilitates efficient penetration by creating a vesicle containing the hydrophilic active ingredients and partitioning them from the surrounding lipophilic matrix. Besides the facilitation of penetration, also the bioavailability is improved while the activity is enhanced. Studies demonstrate that Trimethylpentanediol/Adipic Acid Copolymer accelerates the rate of skin lightening allowing a reduction of the required use level of active ingredients.