Lecture 4

Question 1

External causes of dry skin

Answer 1

Low humidity, air currents, solvents, UV radiation

Question 2

Intrinsic factors of dry skin

Answer 2

Impaired SC function, Reduced sebum production, dietary deficiency

Question 3

Emollients

Answer 3

provide partial occlusion that soothes, moisturizes, and improves appearance of the SC by masking rough, scaly skin

Question 4

Occlusive Agents

Answer 4

form a film on the surface of the skin and moisturize by retaining water in equilibrium within the skin

Question 5

Humectants

Answer 5

bind water from the environment and help by retaining water in equilibrium within the skin

Question 6

Enhancers of skin barrier

Answer 6

mimic the SC bilayers structure and assure long-lasting moisturization

Question 7

Criteria of selecting emollient ester and occlusive ingredients

Answer 7

Structure, polarity, spreading behavior, mol weight, viscosity, stability, solubilizing behavior, permeability into skin, and moisture retention

Question 8

High MW esters

Answer 8

deliver low spreading

Question 9

Low MW esters

Answer 9

deliver high spreading

Question 10

Low viscosity emollients

Answer 10

Deliver High spreading

Question 11

High viscosity emollients

Answer 11

Deliver low spreading

Question 12

Squalane (C 30)

Answer 12

Saturated branched chain hydrocarbon. Colorless, odorless, transparent, chemically stable, inert, does not oxidize or turn rancid. part of sebum

Question 13

Fixed oils

Answer 13

liquid triglycerides - fatty acid storage in oil seeds

Question 14

Butters & Fats

Answer 14

semi-solid triglycerides - usually melting above or near ambient temperature

Question 15

Waxes

Answer 15

distinctly solid lipids primarily fatty acid esters

Question 16

Iodine value

Answer 16

chemical interaction with molecular iodine, measure of unsaturation - dbl bonds

Question 17

PUFA

Answer 17

polyunsaturated fatty acids - high iodine

Question 18

Acid value

Answer 18

alkali KOH neutralization/titration, measures free fatty acids

Question 19

Saponification value

Answer 19

alkali KOH hydrolysis/titration, measures triglyceride esters

Question 20

Unsaponifiables

Answer 20

determine % of, includes sterols, tocopherols, triacontanol hydrocarbons (squalene)

Question 21

Peroxide value

Answer 21

measure of the degree of oxidation of a particular oil sample

Question 22

Lanolin

Answer 22

classified as wax, composed of alcohol and sterol ester - “wool wax”. Very complex but has a lot of high MW molecules.

Question 23

Esters

Answer 23

formed form reaction between a fatty acid and a fatty alcohol.

Question 24

Humectants

Answer 24

Hygroscopic, have hydroxyl groups, act as freeze point depressants, act as skin moisturizers, maintain an equilibrium with water vapor in air.