Dry Skin & Moisturization Flashcards
What are emollients?
Substances which soften and smooth the skin.
What are moisturizers?
Substances which add water retention in skin and/or relieve skin dryness
How do emollients soften and smooth the skin?
Lubrication of skin surface, encouraging skin water retention, altering phase behavior of skin lipid barrier, affecting product texture and afterfeel.
Characteristics of dimethicones
water repellant, insoluble in water and common oils, good antifoam, and have excellent slip/lubricant qualities
Characteristics of cyclomethicone
A volatile fugitive emollient, available as a tetramer and pentamer, anti-tack agent for antiperspirants, and is a solvent for dimethicones.
Mechanisms within SC to hold moisture
intercellular lamellar lipids, presence of fully matured corneodesmosome-bound and ceramide hydrophobed corneocytes, and NMF.
Kligman recession test for moisturizer efficacy
Put ~50 subjects on soap for 2 weeks in winter. Apply moisturizer (exact amt) on marked area, and grade dryness every week. Critical period is after 21 days when treatment ceases.
Highley Dry Skin Test
soap induced dry skin. Wash and dry cycles after application of moisturizer, then repeat for 5 days
Characteristics of glycerin
humectant moisturizer, natural product from soap production, long history of safe use, and effective treatment for dry skin at 5% and higher
Desmosomal components
desmoglein 1, plakoglobin, and corneodesmin. Necessary for desquamation.
Natural Moisturizing Factor - NMF
Ingredients derived from the breakdown of fillagrin after it has served its function as the “stacking protein” for keratin fibers. Includes AA (40%), pyrolidone carboxylic acid (12%), lactate (12%) and urea (7%).
Function of Urea in skin
Humectant ingredient, component of NMF, claimed to be keratolytic at high concentrations. Plasticizer as well as hydrating agent. Enhances barrier fn of skin.
