Nabila Belhaj¹*, Daniela De Lucia², Carine Bézivin¹, Estelle Loing³
*Corresponding author
1. IFF/Lucas Meyer Cosmetics, Champlan, France
2. IFF, Neuilly sur Seine, France
3. IFF/Lucas Meyer Cosmetics, Québec, Canada

Abstract

Skin with its 1.8 m², is the largest organ of the human body and act as a protective barrier against toxins, mechanical stresses, water loss and participates in immune responses. Due to the epidermis bio-architecture based on five layers with polarity increasing from the outer to the inner layers, it is difficult to efficiently deliver hydrophilic molecules to viable cells. Several solutions have been exploited to enhance the skin bioavailability of hydrophilic active molecules such as disruption of the lipid matrix, the use of agents able to modify polarity of the stratum corneum or the use of biomimetic systems such as liposomes.

The main advantage of using liposomes consists of the fact that the epidermis does not get damaged and phospholipids remain on the skin improving its barrier functionality and then its hydration. The main drawback connected with the use of liposomes is their low resistance to surfactants and electrolytes, which limits their potential applications.

In this paper we present a modified liposomal system with enhanced resistance to surfactants, both SDS (sodium dodecyl sulfate) and SLES (sodium lauryl ether sulfate) and high tolerance to electrolytes. In this study we also report data demonstrating that the modified liposomal system maintains the same efficiency in the delivery of hydrophilic molecules compared to classical liposomes (in vitro and clinical tests).

INTRODUCTION

Skin with its 1.8 m², is the largest organ of the human body and act as a protective barrier against external aggressions, water loss and participates in immune responses. It is primarily divided in epidermis, dermis, and subcutaneous tissue. Due to the epidermis bio-architecture based on five layers (stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale) with polarity increasing from the outer to the inner layers, it is difficult to efficiently deliver hydrophilic molecules through it. Several solutions have been explored to enhance the skin bioavailability of hydrophilic active ingredients such as disruption of the lipid matrix, agents able to modify polarity of the stratum corneum, or biomimetic systems such as liposomes. Liposomes were first introduced in personal care formulas by L’Oréal and Christian Dior in 1986 and 1987 respectively (1) and since then, the interest of the cosmetic market towards it has never decreased.

The main advantage of using liposomes consists in the fact that the epidermis does not get damaged and phospholipids remain on the skin improving its ...