Exploring the Potential of Using Micro- and Macroalgae in Cosmetics
Gokare A. Ravishankar, Ranga Rao Ambati in Handbook of Algal Technologies and Phytochemicals, 2019
Moisturizing and hydration are vital for skincare, important for maintaining healthy looking skin as well as its elasticity. Hydration also helps by strengthening barrier capacity against harmful environmental factors (Bedoux et al., 2014). The amount of water present in the epidermis (60%) is determined by hygroscopic substances known as natural moisturizing factors (NMFs). These NMFs contain amino acids (40%), including serine (20–30%), lactic acid (12%), pyrrolidone carboxylic acid (12%), urea (8%), sugars and minerals (Couteau and Coiffard, 2016). The aforementioned components can act as humectants, and thus the topical application of those compounds can improve the skin’s moisturizing ability and relieve dry skin conditions (Pimentel et al., 2018).
Glycerine in Oral Care Products
Eric Jungermann, Norman O.V. Sonntag in Glycerine, 2018
The “humectant” in oral care products must serve many functions and possess properties beyond simple humectancy. A dictionary definition of humectant is “a substance which promotes the retention of moisture.” That, of course, is still the primary purpose of humectants in oral care products. The product formulator, however, must be concerned with functions and characteristics other than water retention. The choice of “humectant,” in the broader sense in which the term is used by the formulator of oral care products, is decided by multiple, interrelated factors. These are considered here with emphasis on glycerine; alternatives to glycerine are discussed elsewhere in this volume.
Humectants in Personal Care Formulation: A Practical Guide
Randy Schueller, Perry Romanowski in Conditioning Agents for Hair and Skin, 2020
The key characteristic of a humectant is hygroscopicity. Hygroscopicity is the ability of a material to hold (or bind) moisture to itself. A useful humectant will retain moisture over a wide range of humidity conditions and for an extensive time period. There are two ways of expressing the hygroscopicity of a humectant: (1) equilibrium hygroscopicity and (2) dynamic hygroscopicity. Both these descriptors are important in choosing a humectant for personal care applications.
Vehicles for atopic dermatitis therapies: more than just a placebo
Published in Journal of Dermatological Treatment, 2022
Simon G. Danby, Zoe D. Draelos, Linda F. Stein Gold, Amy Cha, Bonnie Vlahos, Laraine Aikman, Paul Sanders, Dan Wu-Linhares, Michael J. Cork
Although pure ointments display good occlusion, emollient creams and gels exhibit limited occlusive effects due to the reduction in waxes and oils (52). In these cases, humectants are often added to improve their moisturizing effects. When applied to the skin they help replenish the low levels of NMF associated with AD (Figure 2) (59). Polyols are particularly effective humectants, with glycerin (synonyms glycerol and glycerin) commonly found in emollient creams and lotions (46). Other humectants that can be found in emollients include pyrrolidine carboxylic acid, lactic acid, and urea, which are constituents of NMF in the skin. In very dry environments, humectants exhibit reduced efficacy. Under such circumstances, glycerol and urea have been found to soften the skin by inhibiting the transition of the intercellular lamellar lipids from liquid to solid crystal phase. This skin conditioning property is also associated with increased permeability, meaning humectants like glycerol and urea can be utilized in vehicles as penetration enhancers (60,61).
Trends in nanoformulations for atopic dermatitis treatment
Published in Expert Opinion on Drug Delivery, 2020
Estefânia Vangelie Ramos Campos, Patrícia Luiza De Freitas Proença, Lorena Doretto-Silva, Vinicius Andrade-Oliveira, Leonardo Fernandes Fraceto, Daniele Ribeiro de Araujo
Moisturizers are the most used excipients as non-pharmacological therapy for several inflammatory skin disorders by attenuating their emergency symptoms. The moisturizer formulation benefits are attributed to their composition with a variety of compounds playing different functions: i) occlusive (e.g. petrolatum, lanolin, bee wax, etc.) that forms a hydrophobic layer on the skin surface and reduces the tans-epidermal water loss (TEWL); ii) humectants (e.g. glycerin) for protecting against drying; iii) vegetable oils containing essential free fatty acids (sunflower, safflower, corn, etc.) and/or skin-lipids (e.g.ceramides and their derivatives) for restoring the skin barrier; and iv) botanical ingredients with anti-inflammatory molecules (e.g. apigenin) [18,19].
Dry skin management: practical approach in light of latest research on skin structure and function
Published in Journal of Dermatological Treatment, 2020
Ehrhardt Proksch, Enzo Berardesca, Laurent Misery, Johan Engblom, Joke Bouwstra
A humectant should be part of an emollient formula designed to manage dry skin conditions. Newer research findings confirm that there is a compelling scientific rationale for the currently used humectants. Physiological humectants, such as glycerol and urea, are the preferred choices when used at the right concentration. However, humectants that incorporate additional functions are also viable options for inclusion in topical emollients.
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