mid 1 Flashcards
babylons used soap in which year and how did they make it
2800BC
soap by boiling fats with ashes and water
cleopatra and soap
bathed in milk high in lactic acid
greeks bathed for
aesthetic reasons
large scale commercial soap making occured in
late 18th century when the french chemist nicolas leblanc patented a process for soda ash
how do skin cleansing products work
facial cleasing products contain surfactants that are used for emulsifying water insoluble ingredients into micelles that can be washed away from the skin
ideally a soap should not interfere with the skins sturcture and function that leads to irritation, dryness, redness and itching
however most soaps do cause a change in the skins structure and barrier function
why do surfactants solubilize lipids
surfactants solublize lipids on the skin surface to provide protection and may even extract skin components
what happens if surfactant remains in the SC
remains in SC even after rinsing and damages SC structure
describe the tendency of surfactnats to damage skin proteins
related to the charge density of the surfactant aggregates
chaning the pH may
damage the Sc
describe pH of soaps and syndets
soap based cleansers are alkaline in nature whereas syndets ( synthetic based soap cleansers) are close to neutral or slightly acidic
ideal characteristics of skin cleansing products
NF SAO
RM CWH
SSM R FPPD
nuetral or pleasant odor and color
easy to rub with good foaming properties
easy to spread
pleasant feeling with aplication
non oily non greasy feeling
leaves no residue
moisturizes the skin while cleansing
non comedogenic
well toerated and non allergenic
hand sanitizers should not dry the skin and kill bacteria and viruses
s
long term stability
smooth texture
no microbial contamination or growth
appropriate rheological properites
appropriate foaming prop
approp performance
approp pH
dermatological safety
classification of cleansing pod (4)
chemical nature and mildness
soaps - salts of fatty acids
snthetic surfactants soapless - milder tot he skin PH 7
solvents - alcohols
cleansing principle
chemical cleaning - surfactant emulsifying and dissolving the dirt on the skin, requires water and a rinsing step
physical cleaning - abrasion and friction
foamability
foaming cleansers - sig amt of well foaming surfactants
normal foaming cleansers - LOWER level of well foaming surfatnts
non foaming cleansers - faceial toners, hand sanitizers
product tyope
solid
semi solid
liquid