Skin productsQuestion work

throughNeil WatsonThe Body Shop

April 18, 2023

2

•Cleansing Products•Moisturising Products•Controlling Body odour and sweating•Sun Protection•Removal of unwanted hair

Skin Products

Question - Hair Removal

Answer all parts:-   a) What do you understand by the term “Epilation” and “Depilation”?

( 2 Marks)  b) List methods of unwanted hair removal both mechanical and chemical.

( 2 Marks)

  c) What are the ideal properties of a wet shaving product?

( 5 Marks)   d) Describe the basic components of a soap based shaving product and their

effects. ( 7 Marks)

  e) List the properties of a good chemical depilatory product. (

7 Marks)  f) Explain how the active ingredients used in a chemical depilatory work.

( 2 Marks)

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Answers

a) Epilation – is a process of hair removal from below the skin’s surface

Depilation – is a process of the temporary removal of hair from the surface of the skin.

b) Mechanical hair removal – Tweezing, Threading, Electrical epilation, Electrolysis, Sugaring, Waxing and shaving

Chemical hair removal – Thioglycollate, Enzymes

 

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c) The hallmarks of a good wet shaving preparation are twofold:

i) to soften the hair ii) to act as a lubricant between hardware and the

skin. The product must foam quickly and copiously,

foam must be stable enough to last throughout shaving process, foam must surround, separate and hold hair.

Product must soften and swell hair and lubricate the skin to reduce blade resistance thus preventing razor burn, must be non-irritating to the skin and should have a pleasant fragrance.

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d) Basic ingredients of soap based shaving products and its effects:– Short chain fatty acids (e.g. C12 – C14) – imparts large

quantity of loose foam quickly, but can be more irritant to skin

– Long chain fatty acids (e.g. C16 – C18) – imparts small quantity of thick foam, hardening effect on soap

– Triethanolamine – imparts fast copious foam, soft effect on soap

– Potassium hydroxide solution – imparts copious foam of soft nature

– Sodium hydroxide solution – imparts moderate foam which is hard

– Glycerine – stabilises foam and prevents it from drying out, softens soap

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e)Two types of depilatory are:-

i) Thioglycollate ii) enzyme based system

A good chemical depilatory should have the following properties:-

1 - softens hair to aid rapid removal within 7 to 20 minutes (shorter time for fine hair, longer time for coarse hair)

2 - non-toxic, non-irritating to the skin3 - cosmetically elegant: economical to use, easy to apply, stable in

the pack, acceptable smell4 - no damage caused to clothing5 - the pH must not exceed 12.7, otherwise it will cause severe skin

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f) Chemical Thioglycollate based depilatories work by breaking disulphide linkage in the keratin hair fibres, and totally disintegrate the hair

OR

The principle of the chemical depilatory depends on the extensive swelling of hair fibres because of disulphide bond reduction and the effect of high

pH on hydrogen bonding.

The final de-hairing of skin is achieved by scraping with a blunt instrument or rubbing with terry cloth of the depilatory-treated skin area

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QUESTION - Suncare

Answer all parts:- a) Define what is meant by the term sunscreen.

( 2 Marks) b) Give examples of chemical and physical sunscreen agents and explain the difference between them in terms of their mode of action.

( 6 Marks) c) Give examples of UVA and UVB sunscreens.

( 2 Marks) d) Describe the procedure for measuring SPF in human test volunteers.

( 8 Marks) e) Explain how a sun protection factor (SPF) is calculated.

( 7 Marks)

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a) A Sunscreen is the UV light absorbing agent that helps to lower the incidence of dermal malignancies. The function of the sunscreen is the protection of the skin from damaging UV light.

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b) Chemical Sunscreens; chemically absorb ultraviolet lightEthylhexyl SalicylateEthylhexyl MethoxycinnamateEthylhexyl dimethyl parabenBenzophenoneOctylcryleneHomosalate

Physical Sunscreens; works by reflecting and scattering UV lightThey are micronized, highly insoluble organic molecules such asGuanineOr Inorganic like, Titanium DioxideZinc Oxide

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c) UVA filter: Benzophenone, Butyl Methoxy dibenzoylmethane, methyl anthranilate

UVB filter: PABA, Ethylhexyl Salicylate, Ethylhexyl Methoxycinnamate

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d) Measurement is done under controlled conditions, in the presence of a highly skilled scientist (preferably dermatologist)

 The following steps are involved: Step I – Selection of suitable panellists (minimum10) with skin type I to III with

written consentStep II – suitable test sites, usually panellists back are marked to measure

MEDStep III – the test sites (unprotected skin) is exposed to graduated increasing

amount of UV radiation (290 – 300 nms) from solar simulator lampStep IV – test sites are checked about 24 hours after exposure Step V – the dermatologist picks out the sites showing MEDStep VI – test product is applied to randomised test sites and allowed to rest

for at least 15 minutesStep VII – then the test sites exposed to UV radiation using solar simulating

lamp for a set timeStep VIII – After irradiation test sites are examine for any reddening /

darkening and re-examined after 24 hoursStep IX – SPF is calculated for each panellist and SPF is worked out for the

group using statistical means

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e) SPF = Time to produce erythema in protected skin

Time to produce erythema in unprotected skin OR SPF = MED with sunscreen MED without sunscreen MED – minimal erythemal dose

Sun protection factor (SPF) testing is a measure of the ability of UVB to cause erythema in the skin, the test relies on the accurate detection of first sign of erythema by measuring the minimal erythemal dose.

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QUESTION – Skin Cleansing

Answer all parts:- a. Classify the main types of skin cleansing formulations

available on the market.

( 5 Marks)

b. List the common active raw materials used for cleansing dry, normal

and oily skin. (10 Marks)

c. Describe the advantages and disadvantages of using:- i) Soap. ii) Synthetic detergents. iii) Emulsion cleansing products

( 7 Marks)

d. Give examples of the protection and repair requirements that consumers may expect in skincare products. ( 3 Marks)

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a) Soap. (Superfatted soap, Transparent/ Glycerin soap, Translucent/ pearlised soap, Combo Bars (Dove Beauty Bar, Syndet bars.)

Emulsions. (Creams, Lotions, Milk, Cold Cream, Rinse –off emulsions (foaming cleansers)). Liquid synthetic detergents. Gels. (Surfactant, basic viscous lotion). Wipes. Masks. Mousse. Scrubs. Toners.  

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b) Raw Materials used for Cleansing dry skin. Emulsion products; w/o or o/w emulsions which combine the solvency of water

and oils to effect cleansing of the skin containing high levels of emollients (oils) generally between 35-65%

Emollients – IPP, IPM, Mineral Oil, Jojoba Oil, Vegetable Oil and Menthol for cooling agent.   Raw Materials used for Cleansing Normal and Combination skin. These include soap, combo bars, synthetic detergents (syndet bar), liquids

containing mixture of fatty acid salts, Fatty Acid Esters, (C12 – Sodium Laurate, C14 – Sodium Myristate, C16 – Sodium Palmitate, C18 – Sodium Stearate,

C18 – Sodium Oleate), Silicones, Triglycerides oils/fats, (Lauric, Myristic, Palmitic, Linoleic, Palm oil, Palm kernel oil and Coconut oil).

  Raw Materials used for Cleansing Oily skin Frequent and effective cleansing is recommended for oily skin in order to keep

the amount of sebum left on the skin to minimum thus avoids development of the spots and pimples. Skin toners/Masks.

Ethanol, Witch Hazel, IPA, Antibacterial agents and Salicylic Acid.

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C) SoapAdvantages – inexpensive

Produces a rich latherRinses off easily

Disadvantages - extremely alkaline(pH9-10) which can cause irritation, dryness and scaling.

In hard water areas soaps can leave scum deposits on the washbasin

Synthetic detergentsAdvantages- Mild to the skin

No scumCan be formulated to match the skins pHBecause they have a lower pH than soap they are more

versatile in terms of fragrance, colour etc.Disadvantages

The lather is not as good as soaps and not always rich and creamy. They can sometimes be quite difficult to rinse off

Emulsion cleansing productsAdvantages They can leave a layer of emollient oil on the skin to keep it

smooth and supple.Much greater versatility and variation in product typesAre easily adapted for different skin types

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d) A consumer might expect the following from their skincare product:

Protect their skin from UV damage or other environmental factors(Such as pollution, smoke etc.)

Maintain levels of moisturisation by adding moisture directly to the skin, and by reducing loss of moisture(increasing barrier function, reducing TEWL)

Repair the skin if damaged through sun exposure or ageing by stimulating collagen and elastin synthesis or increasing cell renewal/turnover providing the consumer with smoother skin.

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QUESTION - Moisturisation

Answer all parts:-a. Explain why moisturisers are recommended for dry skin, defining moisturisation, emollients and humectancy. (11 Marks)b. Give examples of raw material types that are commonly used as:-

i) Emollients ( 4 Marks) ii) Humectants. ( 4 Marks)c. Discuss some of the new functional materials that are now available as special additives for moisturising products. ( 6 Marks)

a)Dry skin often manifests itself with patches of scaly or rough skin, and is usually white and flaky. This is because when the skin is dehydrated the corneocytes (skin’s scales) become rigid and more visible. This can be temporarily reversed by using a suitable moisturising cream. The moisturiser will increase the water content of the stratum corneum leaving the skin soft, smooth and supple. This is because the corneocytes have become more pliable and transparent – and therefore less visible. So moisturisation is a method whereby the water content of the stratum corneum is temporarily increased through the application of a skincare product.

Moisturisers are generally made up of a combination of emollients and humectants because they both work in different but complimentary ways.

Emollients, which are materials such as an oil or wax, often work through an occlusive action, which means they form a barrier to water loss and therefore reduce TEWL. This in turn increases the level of water in the SC. They also make the skin feel smoother very quickly as they have the ability to ‘fill in’ the cracks of the horny layer and ‘glue down’ the protruding corneocytes. Common examples of emollients are mineral oil and lanolin

Humectants exhibit hygroscopic behaviour, this means they draw in, and hold onto, large amounts of water. When applied to the skin the humectant reduces TEWL by holding onto the water in the skin in the intercellular lipid matrix found between the corneocytes in the SC. Common examples of humectants are propylene glycol and glycerine.

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b) (i) Common emollients:Hydrocarbons Mineral Oil, petrolatumLanolin Derivatives Lanolin Oil, lanolin AlcoholFatty Acids Stearic acid, linoleic acidFatty Alcohols cetyl alcohol, stearyl alcohol,

cetearyl alcoholEsters isopropyl myristate, Isopropyl palmitate,

Jojoba oilTriglycerides Sesame oil, Sweet Almond oil,

Cocoa Butter, sunflower oil

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b (ii) Common HumectantsPolyols – propylene glycol, Glycerin,

sorbitolsAmino Acids – Hydrolysed animal proteins,

collagen, Milk protein, Silk amino acids

Others such as Urea, Lecithin, Aloe Vera, Lactic acid

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Special additives

c) Hydroxyacids, such as Salycilic, lactic, malic etc affect the epidermal renewal process by reducing corneocyte adhesion in the basal layer of the stratum corneum, increasing cell turnover, providing smoother skin, reducing hyper pigmentation and they have a long term increase in collagen and elastin synthesis. Lactic and glycolic acids are most effective but you need to formulate carefully as they can be irritating and pH needs to be around 4.5

Vitamins – Vitamins can provide a good holistic approach to wellbeing, but have a functional use too. Vitamin E (dl alpha tocopherol) is a good antioxidant and free radical scavenger. Vitamin A derivatives can be used to treat sun damaged skin, as it can normalise epidermal activity and reduce hyper pigmentation. Vitamin C(ascorbic acid) is another natural antioxidant that regulates collagen synthesis. Vitamin C is quite unstable and can oxidize easily, nowadays the best delivery systems are microcapsules or liposomes or the more liposoluble forms of ascorbic acid such as hexyldecanoyl ascorbic acid.

Essential Fatty Acids(EFAs). EFAs such as linoleic and gamma linolenic acid are important building blocks of ceramides. When applied topically through a skin cream they can be incorporated in the SC structural lipids, improving the skins suppleness and flexibility.

Proteins and glycosaminoglycans. Proteins such as silk amino acids are very substantive to the skin, and leave it feeling soft and smooth. Hyaluronic acid absorbs considerable amounts of water, and although they can’t penetrate the SC they form a semi permeable layer on the surface and reduce TEWL.

Polysaccharides – derived form oats, wheat, bakers yeast – these can affect the skin in a number of ways ; reducing irritation caused by detergents, increasing cell turnover in the SC, stimulation of collagen synthesis.

Delivery systems – many new delivery systems have been developed over the years that can encapsulate usually unstable materials that are only exposed upon contact to the skin. Or liposomes that are very compatible with the skin and can penetrate into the SC and deliver their active content.

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