Moisturizers & Dry Skin Flashcards
Hemidesmosomes are located
between basal layer keratinocytes and basal lamina
Langerhans cells are located
Spinosum layer
Characteristics of keratinocytes in stratum basale
Stem cell niche
Desmosomes
K5 and K14 expressed
Characteristics of keratinocytes in stratum spinosum
Profilaggrin
Desmosomes
Keratin intermediate filaments
Characteristics of keratinocytes in stratum granulosum
Filaggrin (active)
Crosslinked keratin fibers
Lamellar bodies secrete lipid precursors
lipids in stratum corneum
Cholesterol ester
omega-hydroxyceramide
Sphingosine
Lipids in stratum basale and spinosum
- Cholesterol
- fatty acids
- triacylglycerides
- phospholipid
lipids in stratum granulosum
- cholesterol sulfate
- Ceramide, glucosylceramide, acylglucosylceramide
- Sphingomyelin
External factors causing dry skin
- Low relative humidity
- Wind currents–> evaporation
- Solvents/detergents stripping lipids
- Inflammation from UVR
Intrinsic factors causing dry skin
- Impaired SC function
- Reduced sebum production
- Dietary deficiency of essential fatty acids
Examples of impaired SC function
- Increased TEWL
- Abnormal keratinization/desquamation
- Reduced levels of NMF
Top 5 causes of dry skin
- Lifestyle
- Over-cleansing
- Sun exposure
- Extreme climactic conditions
- Aging
Vehicle types for moisturizers
- o/w emulsion
- w/o emulsion
- lamellar gel systems
Key ingredients of moisturizers
- Emollients
- Humectants
- Occlusive agents
Mechanism of emollients
- partial occlusion/lubrication
- affect skin FEEL
- “smoothing”
Mechanism of occlusive agents
forms a film on the surface of the skin to retard evaporation of water
Mechanism of humectants
binds water from the environment and retain water in equilibrium with the skin
Moisturizers that enhance skin barrier work by
mimicking the SC bilayer structure and assure long-lasting moisturization
Emollients provide _______, ________, and improve __________ while moisturizers provide _______ and improve ________
lubrication, skin smoothing, skin FEEL
water retention, barrier function
Categories of emollients
- silicones
- hydrocarbons
- esters
- ethers
- triglycerides
Occlusive moisturizers
- petrolatum
- dimethicone
- mineral oil
Humectant moisturizers
- Sodium lactate
- Glycols
- Sorbitol
- Sodium PCA
- Sodium hyaluronate
- polyglutamic acid
- hydrolyzed starch
Emollient moisturizers (specific)
- lanolin
- Capric caprylic triglyceride
Ester emollients
- Alkyl Benzoate
- Isopropyl Palmitate
- Octyl Palmitate
Hydrocarbon emollients
- Squalane
- Mineral oil
Ether emollient
PPG (polypropylene glycol)
High viscosity emollients
- Castoryl maleate
- Diisosteryl dimerate
Low viscosity emollients
- Dicaprylyl ether
- Cyclopentasiloxane
- Isopropyl myristate
emollients with medium spreading and fatting
- caprylic triglycerides
- squalane
- isocetyl stearate
emollients with low spreading and high fatting
- isocetyl stearoyl stearate
- oleyl oleate
Fixed oils are
liquid triglycerides
Butters and fats are
semi-solid triglycerides
Waxes are _________, primarily _______
solid lipids
fatty acid esters
Primary components of oils and fats in nature are
Saponifiable triglycerides
Unsaponifiables
Acetone insolubles
Unsaponifiable components of oils and fats include
Hydrocarbons
Tocopherols
Sterols
Titer point number line for oils butters and fats
Oils
Iodine value provides a measure of
Unsaturation (double bonds)
PUFA have ____ iodine value
high
Acid value provides a measure of
free fatty acids
Saponification value provides a measure of
triglyceride esters
Peroxide value provides a measure of
degree of oxidation of a particular oil sample
When formulating with vegetable oils, each oil has a specific _________
required HLB value for the nonionic emulsifier
Characteristics of lanolin
Self-emulsifying W/O base
“wool wax”
alcohol + sterol esters
absorbs/retains high levels of water
CCT is a naturally derived emollient through
transesterification
Squalane is a naturally derived emollient through
hydrogenation
Jojoba wax is derived through
transesterification and hydrogenation
Myristyl myristate is derived through
esterification
Esters are formed by reactions between
fatty acid + fatty alcohol
Linear esters ___________________, while branched esters ________________
Linear: enhance slip, feel heavy
Branched: dry initial feel, spread easily
High-spreading esters with dry after feel
- Diisopropyl Adipate
- Hexyl Laurate
- Isopropyl (Myristate/Palmitate/Isostearate)
To reduce the tackiness of heavier ingredients such as petrolatum and castor oil, one could add
high spreading esters with dry after feel such as diisopropyl adipate, hexyl laurate, isopropyl myristate
High-spreading esters with velvety after feel
Branched
(Tridecyl/Isostearyl/Isodecyl) Neopantonoate
Medium-spreading esters with medium after feel
Isocetyl stearate
Cetearyl Isononanoate
Ingredient that can improve intermediate tackiness, may be used to replace mineral oil for a smoother after feel
medium-spreading esters like isocetyl stearate and cetearyl isononanoate
Low-spreading esters with rich after-feel
Highly branched
Isocetyl Stearoyl Stearate
Octyldodecyl Stearoyl Stearate
Benefits of silicone fluids
- Very resistant to high temp
- Very resistant to oxidation
- Easily spreadable (Breathable films)
- Good detackifiers
MW range of volatile silicone fluids
300-600
Types of hydrophilic emollients
- PEGs/PEG esters
- Silicone copolyols
- ethoxylated alcohols/natural oils
Cutometer, Twistometer, and Ballistometer measure
skin elasticity resiliency
Laser Doppler blood flow measures
Erythema and vasodilation
