INTRODUCTION
Cleansing is an important hygienic activity for maintaining skin health; however, cleansers cannot distinguish between the lipids from sebum and environmental dirt and the intercellular lipids necessary for a robust skin barrier. A careful balance must be created when designing a cleanser formulation to remove enough water- and oil-soluble dirt without worsening sensitive skin. The substances that produce cleansing are known as surfactants. A new method to achieve this cleansing balance while respecting the skin barrier is the development of polymeric surfactant cleansing technologies. These technologies can provide premium cleansing and foaming aesthetics while minimizing surfactant penetration into the skin.1 Surfactant penetration occurs when the skin is exposed to highly alkaline detergents that swell the stratum corneum, enabling penetration. Much of the skin tightness that is experienced post-cleansing is an indication of cleanser penetration through the stratum corneum and the interaction between proteins and lipids in the epidermis2 resulting in skin tightness, skin dryness, epidermal barrier damage, erythema, irritation, and itching.3-7
The key to cleansing is the formation of micelles, which are spheres that have a hydrophobic interior to solubilize oily dirt and a hydrophilic exterior to allow the oily dirt to dissolve in water. The foaming action and mildness of the cleanser are influenced by the surfactant charge and formation of micelles helping to remove lipids from the skin surface.1,3,8 Hydrophobically modified polymers (HMP), such as potassium acrylate copolymer, physically associate with surfactants, resulting in the formation of polymer-surfactant complexes that are less irritating to the stratum corneum lipid barrier.1,9,10 HMPs interact with the hydrophobic tails of other surfactants, leading to the formation of larger surfactant structures and a reduction in the surfactant dynamics. HMPs also lower the effective concentration of free surfactant micelles in solution and facilitate foam formation.10 HMPs can also be combined with the next-generation polymeric cleansing technology,
The key to cleansing is the formation of micelles, which are spheres that have a hydrophobic interior to solubilize oily dirt and a hydrophilic exterior to allow the oily dirt to dissolve in water. The foaming action and mildness of the cleanser are influenced by the surfactant charge and formation of micelles helping to remove lipids from the skin surface.1,3,8 Hydrophobically modified polymers (HMP), such as potassium acrylate copolymer, physically associate with surfactants, resulting in the formation of polymer-surfactant complexes that are less irritating to the stratum corneum lipid barrier.1,9,10 HMPs interact with the hydrophobic tails of other surfactants, leading to the formation of larger surfactant structures and a reduction in the surfactant dynamics. HMPs also lower the effective concentration of free surfactant micelles in solution and facilitate foam formation.10 HMPs can also be combined with the next-generation polymeric cleansing technology,
