Sunscreen

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2. • Beneficial effects:
• Sunlight promotes vitamin D synthesis through the
activation of 7- dehydrocholesterol contained in skin
fat.
• Increases the formation of hemoglobin and also
decrease blood pressure.
• Activate various hormones , vitamins, enzymes
• Moderate exposure -- better physiological feelings ,
fitness, peace of mind.
• Sun rays cause thickening of skin by producing melanin
which increases body's natural protective mechanism
against sun burns.
• Reduces the symptoms of modern ailment SAD
(Seasonal Affective Disorder)
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3. Adverse effects: (excessive sun exposure)
• Sun burn with symptoms of mild irritation to serious
inflammation, from a slight erythema to blistering on
skin.
• Release of histamine by the sun affected cells 
dilation of blood vessels and erythema
• Skin cancers
• Destroys vitamin-D present in skin fat and produces
some toxic steroids
• Dermatological disorders
• Wrinkled appearance of skin
• Premature skin ageing
• Pain, redness and permanent damage of underlying
skin
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4. 4

5. Electromagnetic Spectrum

6. UV Light
• UVC
• Most damaging
• Little makes it
through atmosphere
• UVB
• Still damaging
• Most common cause
of skin cancer
• UVA
• Least damaging
• Causes many of sun’s
aging effects

7. Sun Light
• Wavelength ranges from 1000nm to 100nm
• 1000-750nm is IR, detectable as heat
• 750-400nm is visible light, enabling to see objects
• 400-100nm is UV region responsible for adverse
biological reactions like sunburn, skin
ageing/tanning, photo-dermatoses, immuno-
suppression and skin cancer
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8. UV Radiation
• Far- UV (100-200nm)
• UV-C (200-280nm)
• UV-B (280-320nm)
• UV-A (320-400nm)
• The far UV and UV-C are germicidal because of its
ability to kill single cell organisms and are prevented
from reaching the earth’s surface by the ozone layer
• UV-C radiation at very low exposure levels is both
cytotoxic and produce severe sunburn
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9. • UV-B (burning – simply referred so) is the primary
initiator of sunburn, contributing approx. 85% of
summer sunburn reaction.
• Initiation of photodermatoses, skin cancers,
• premature skin ageing and for generation of
photoprotective pigment “melanin” responsible for
tanned appearance of skin
• The erythemal reactions develop after 8 hrs of
exposure and may persist for 24 hrs and longer
• responsible for synthesis of Vitamin D in the skin
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10. • UV-A (ageing), its long term effects include
wrinkling and ageing of the skin due to deeper
penetration into the dermis
• It generates both immediate and delayed skin
pigmentation called tanning response (contributes
15% of summer sunburn reaction)
• Direct exposure may lead to polymorphic light
eruption (PLE), solar urticaria, chronic actinic
dermatitis (CAD)
• Immediate pigmentation develops after a few hours
of exposure and reddening may not take place for
up to 72 hrs of exposure
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11. Skin types
• I) always burns easily; never tans
• II) burns easily; tans minimally
• III) burns moderately; tans gradually
• IV) burns minimally; tans easily
• V) rarely burns; tans profusely
• VI) never burns; deeply pigmented
• The consumer should be aware of his/her skin type
and benefits of products which screen against both
UV-A and UV-B
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12. Sun protection factor SPF
• It is the level of protection from sunburn afforded
by a sunscreen product
• It is tested both in-vivo (human volunteers) and in-
vitro (measuring physical absorbance of sunscreen
agent)
• SPF testing is measuring the sunscreen
effectiveness by
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13. 13

14. • Sun burn preparations classified into 3 groups
• 1. sunscreen preparations:
• Either scatter the incident light effectively or they
should absorb the erythemal portion of suns radiant
energy.
Ideal sunscreen agent
• Absorb light preferentially over the range of 280-
320nm
• Be stable to heat, light, and perspiration
• Non toxic and non irritant
• Not be rapidly absorbed
• Be neutral
• Be readily soluble in suitable vehicles
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15. Product ingredients
1) sunscreen agents
- organic
-inorganic
2) Waterproofing agents
3) Emollients and diluents
4) Other ingredients
5) Artificial tanning agents
6) After- sun preparations
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16. Sunscreen agents
• Organic sunscreens:-
1) PABA & its derivatives- UV-B screening agents,
allowable limits is up to 8% (octyldimethyl PABA)
2) Cinnamates- Cinnamic acid esters used up to levels
of 10% (octylmethoxy cinnamate)
3) Salicylates- often used at levels up to 5% ,
protective effect is poor and used as synergist with
other sunscreens and aids their solubility
4) Anthranilates- methyl anthranilate upto 5% in USA
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17. 5)Camphor derivatives- 3-(4-methylbenzylidene)
camphor increases the photostability of product
and used up to 6%
6) Benzophenones- used up to 10% concentration in
combination with UV-B screens for broad spectrum
protection
7) Dibenzoylmethanes- UV-A absorbing materials , in
USA used up to 1-3% and in Europe up to 5%
8) Octocrylene- new sunfilter used up to 10% and
chemically it is cyano-diphenyl acrylic acid-
ethylhexyl ester.
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18. • Inorganic sunscreens:-
• Natural minerals and pigments – talc, kaolin, mica
and metal oxides
• ZnO has good light-barrier properties against UV-A,
UV-B and visible spectrum – broad UV protection
• Titanium dioxide has similar protective properties
that of ZnO and can be used in a combination
• Both tend to give a white colour to the skin when
used in its standard pigmentary form
• The efficiency of titanium dioxide depends on its
particle size. Decreasing particle size decreases
whitening and makes UV protection less broad
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19. Water proofing agents
• PABA type sun filters are more resistant to wash off
than other organic sunscreens as they can
penetrate deeper into the skin layers
• Silicone oils are extremely resistant to water
penetration and form a water repellent film on skin
surface
• Polymeric film formers like alkylated
polyvinylpyrrolidones along with emollient esters
are also gaining importance.
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20. Emollients and diluents
• A uniform and continuous film is desirable to
ensure complete protection
• Heavy, greasy or too tacky materials and too thin
and insubstantive materials should be avoided
• Branched chain esters provide even protective film,
improve skin feel and acceptability of product but
may disrupt the water repellent film due to their
branching
• UV-A screening is enhanced by decrease in polarity
of solvent
• Iso-arachidyl neopentanoate (branched chain
ester)have remarkable SPF enhancing properties
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21. Other ingredients
• Rheology modifiers – increase ease of product
application and efficiency of sunscreen agents
• Humectants – to counteract loss of moisture,
sorbitol, glycerol, propylene glycol
• Anti-oxidants- free radical scavenging and prevents
anti ageing, vitamins E and C
• Vitamin E also has anti- inflammatory properties
and also prolong shelf life, used in a concentration
of 0.05 – 0.2% of free vitamin is recommended
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22. General manufacturing
• Preparations may be Aq or oily solutions, creams or
emulsions, lotions and gel type
• Solutions: aq or oily can be prepared simply by mixing and
dissolving the sunscreen and other ingredients in the vehicle
i.e water or oil. Perfume should be added last
• Creams : These are emulsion type and are prepared by taking
ingredients of oil phase and aq phase separately and heating
to liquefy or dissolve all ingredients and then mixing them
together with continuous stirring till the cream is produced .
Perfume added after cooling
• Lotions can be solutions or emulsion type
• Gels are highly viscous aq preparations – thickening agents
dispersed in water separately, other ingredients are mixed
together and dissolved in water. Then the dispersion of
thickening agent is mixed with others with stirring to prepare
gel.
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23. 2. Palliative preparations
• Used for relief of irritation and other problems
resulting from sunburn
• These are antiseptic preparations
• Eg: calamine lotion containing antiseptics Zn
pheno sulphonate or phenol etc
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24. 3. Simulative preparations
• Artificial sun tan preparations
• They enhance colour and prevent skin damage
by absorption of erythemal radiation
• Normally obtained by staining the skin
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25. Artificial tanning agents
• Use products containing dihydroxy acetone which
reacts with certain free amino acids in proteins near
skin surface to form products which condense and
polymerize to form dark coloured melanoids
• Tablets containing β-carotene or psoralens -
produce a systemic stimulation of a pigmentary
reaction
• Melanin precursors - accelerate tanning process-
mixture of tyrosine and riboflavin , where riboflavin
aid in oxidation of tyrosine and tyrosine intensify
the formation of melanin
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26. • Now both sunscreens and dihydroxyacetone are
combinly formulated so that the consumer can be
protected from the sun and develop an artificial tan
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27. After-sun preparations
• Menthol- cooling effect
• Aloe vera, allantoin, calamine- soothing and healing
effect
• Xylocaine- mild anaesthetic and reduce pain
• Vit E- reduces erythemal effect and promotes
enenzyme activity in healing process
• Vit A- soothing, wound healing, improve elasticity
and moisturizing
• Antimicrobial agents- reduce risk of infection and
shouldn’t be applied on broken or severely blistered
skin
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28. Formulations
• Gels
• Sticks
• Oils
• emulsions
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29. • Gels- extremely attractive, elegant formulation
• Drawback- potential irritancy where alcohol is part
of the formula, relatively low SPF and water
resistant properties
• Sticks- direct application to a small area such as
nose, lips etc, often formulated as opaque
sunscreens with good water repellency due to the
presence of oils and waxes
• Drawback- often expensive to prepare, firmness
should be maintained in hot weather conditions
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30. • Oils- low SPF products and used for a deep coloured
tan, convenient to use, have good level of water
resistance
• Drawbacks- limited sunscreen solubility, low SPF,
form a very thin transparent film on the skin, oils
have become less popular
• Emulsions-most popular fomulation type,
• highly convenient and cosmetically acceptable.
• They may be thick creams to light milks and may be
O/W , W/O or more complex in nature
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31. • Have highest SPF of all formulation types
because they deposit a uniform non-
transparent film on the skin.
• Also penetrate the skin’s horny layer to some
degree thus increasing efficacy and durability
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32. Evaluation
• Spectrophotometric evaluation
• UV radiation absorption ability
• Molar extinction coefficient or absorbancy
determined and compared with other std substance
• Erythemal dosage – erythemally effective radiation
• Solar energy transmitted through the film of suntan
preparation and the effectiveness factor at that
wavelength
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33. • Sunscreen index –relative screening activity of
sunscreen compounds. Measurement of
extinction coefficient at 308 nm wavelength
that is the peak wavelength for effective sun
burn
• In – vivo skin testing – on rabbit backside or
abdomen – exposed to radiation along with
un protected
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34. Reference
“Poucher’s Perfumes, Cosmetics & Soaps”,
10th edition
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