sunscreen importance in the daily use for young

sunscreen

1. SUNSCREENS
Skin damage from radiation is cumulative
whether sunburn occurs or not.
Annual incidence:
500,000 cases of basal cell CA occur.
100,000 cases of squamous cell CA occur.
20,000 cases of malignant melanoma
occur.

2. ULTRAVIOLET RADIATION
SPECTRUM
UVA (Longwave Radiation)
Range 320-400 nm
Erythrogenic activity is weak, however
penetrates dermis
Responsible for development of slownatural
tan
Most drug-induced photosensitivity rxn
occurs
UVA may augment the effects of UVB

3. UVB (Middlewave Radiation)
Range 290-320 nm
Erythrogenic activity is the highest
Produces new pigment formation, sunburn,
Vit D synthesis
Responsible for inducingskin cancer
ULTRAVIOLET RADIATION
SPECTRUM

5. UVC (Shortwave or Germicidal Radiation)
Range 100-290 nm.
Does not reach the surface of the earth.
Is emitted from artificial ultraviolet
sources.
ULTRAVIOLET RADIATION
SPECTRUM

6. Long-term hazards of skin damage
from radiation:
–Malignancy:
•Squamous cell epithelioma
•Actinic keratosis
•Basal cell carcinoma
–Premature aging
•nevus, seborrheic keratosis, solar lentigo
•wrinkles, lines, etc
ULTRAVIOLET RADIATION
SPECTRUM

7. SUNSCREEN CLASSIFICATIONS
Physical
–Opaque formulations containing:
•titanium dioxide
•talc, kaolin
•zinc oxide
•ferric chloride
•icthyol, red petrolatum
–Mechanism: scatters or reflects UV
radiation due to large particle size

8. Chemical
–Formulations containing one or more:
•PABA, PABA esters
•benzophenones
•cinnamates
•salicylates
•digalloyl trioleate
•anthranilates
–Mechanism: absorbs UV radiation
SUNSCREEN CLASSIFICATIONS

9. Sun Protection Factor(SPF) =
MED of Photoprotected Skin
MED of Unprotected Skin
–MED is minimum dose of radiation which
produces erythema
–SPFs are determined indoors using xenon
lamps which approximate the spectral
quality of UV radiation
SUNSCREENS

10. SUNSCREENS
Factors which influence effectiveness of SPFs
–Difference in skin types.
–Thickness of the applied sunscreen.
–Time of day.
–Altitude: each 1,000 ft increase adds 4% to the intensity of
erythema producing UV radiation; thus intensity is about
20% greater in Pocatello than at sea level.
–Environment: snow/white surfaces reflect 70-90%, and
when directly overhead water reflects nearly 100% of UVR.
–Vehicle: determines skin penetration of sunscreen.

11. SUNSCREENSCategorySkin Type SPF
I Always burns, never tans 15 >
II Burns easily 15
III Burns moderately, (avg caucasian) 10-15
IV Burns minimally, tans well (olive skin”)6-10
V Rarely burns, tans profusely (brown skin)4-6
VI Never burns (black skin) none

12. SUNCREEN AGENTS
PABA (Para-aminobenzoic acid)
Very effective in the UVB range(200-320 nm).
Most effective in conc of 5% in 70% ethanol.
Maximum benefit when applied 60 min priorto
exposure (to ensure penetration and binding to stratum
corneum).
Does NOTpreventdrug/chemical-induced
photosensitivity rxn.
Contact dermatitis can develop.
May produce transient drying/stinging from alcohol
content (may be alleviated by adding 10-20% glycerol).
May stain clothing.

13. SUNCREEN AGENTS
PABA Esters (Padimate A, Padimate O,
Glyceryl PABA)
Also very effective in UVB range(280-320)
Most effective in conc. 2.5-8% in 65% alcohol
May penetrate less effectively than PABA
Similar application and adverse effect
Less staining

14. Benzophenones (oxybenzone, dioxybenzone,
sulisobensone)
Slightly less effective than PABA.
Absorbs from 250-400 nm spectrum (ie, UVA & UVB).
Combinedwith PABA or PABA ester improves
penetration and is superior to either agent used alone
(200-400 nm wavelength coverage).
Beneficial in preventing photosensitivityrxns.
Contact dermatitis is rare.
SUNCREEN AGENTS

15. SUNCREEN AGENTS
Cinnamates and Salicylates
Minimally effective, absorb UVB spectrum.
Generally used in combination with one of the
above.

16. SUNCREEN AGENTS
Anthranilates
Minimally effective, absorbs UVA spectrum
250-322 nm.
Usually combined with UVB agent to broaden
spectrum.

17. USE IN YOUNG CHILDREN
Not recommended in children < 6 mos
(due to theoretical concern that percutaneous
absorption may be greater and excretory
functions may not be mature enough to
handle).
No reported cases of toxicity.
Recommend clothing (hats, etc).

18. Tan Accelerators
–Contain tyrosine -necessary for production
of melanin, no evidence to support efficacy
Sunless Tanners
–Dihydroxyacetone darkens outermost layer
–Use at night, sunscreen during day
Tanning Booths
–Newer types use light source composed of
95% UVA, < 5% UVB (even 1% may
increase incidence of skin cancer).
TANNING

19. PHOTOSENSITIVITY REACTIONS
Photoallergic Reactions
–Radiation alters drug, becomes antigenic or acts
as hapten.
–Requires previous exposure.
–Not dose related.
–Induced by chemically related agents.
–Eruption may present as urticarial, eczematous,
bullous, or sunburn-like reactions.
–Usually caused by topical agents.

20. Phototoxic Reactions
–Radiation alters drug to toxic form, causes
tissue damage.
–Does not require previous exposure.
–Dose related.
–No cross-sensitivity.
–Within several hours of exposure -appears
as exaggerated sunburn.
PHOTOSENSITIVITY REACTIONS

21. CHOOSING SPF RATING
HIGH SPF SUNSCREENS
Can achieve higher SPF by combining
two or more agents.
SPF 30 (3%) vs 15 (6%) of radiation
penetrating skin.

22. SUNSCREEN PRODUCTS
PABA/EsterOxybenzoneOther
Coppertone yes cinnamate
PreSun yes yes
Bull Frog yes cinnamate
Q.T. Quick Tanning cinnamate
Formula 405 Solar Lotion cinnamate

23. OTC BURN THERAPY
Burn Depth
–First degree erythema, no blistering
–Second degreeerythema and blisters
–Third degree No blisters, leathery
white, mottled
–Fourth degree“Charred”

24. CLASSIFICATION OF BURNS
(American Burn Association)
Minor Burns:
Second degree burn
Third degree burn
–excludes electrical or
inhalation injuries and all
poor risk patients.
< 15% BSA
(10% in children)
< 2% BSA not involving
eyes, ears, face, hands,
feet, or perineum).

25. Estimation of Burned Area
Rule of nines Body Area
Head 9%
Arm 9%
Leg 18%
Anterior Trunk 18%
Posterior Trunk 18%
Perineum 1%

26. OTC Treatment of Minor
Burns/Sunburns
Ice/cool water
Cleansing -water and nonirritating soap
Dressings (usually only for second degree burns)
–Nonadherent primary layer of sterile fine-
mesh gauze
–Absorbent intermediate layer to draw and
store exudate
–Supportive outer layer of rolled gauze
bandage

27. Formulation
Homomenthyl salicylate 080
Mineral oil 500
Isopropyl myristate 420

28. Formulation (cream)
Suncreen agent 50
Emulsifyer 75
Cetyl alcohol 10
Isopropyl myristate 150
Liquid paraffin 170
Glycerol 30
Water to 1000