SUNSCREENS
©1997, Constantinos D. Verros, MD
Active
ingredients in Sunscreens
Vehicles
& Preservatives that can cause contact dermatitis
Sunscreen formulations
in Greece (Greek only)
References
ACTIVE INGREDIENTS IN SUNSCREENS
Commonly
used SUNBLOCK agents
Zinc
Oxide
Talc
Titanium dioxide
Red vetenary petrolatum
Combinations
DISADVANTAGES : Cosmetically unacceptable, they tend to be messy and can stain clothing.
PABA and PABA Esters
Their primary protective range is found in the UVB range (290-320 nm).
PABA
(260-313 nm)
Padimate O (290-315)
Padimate A (290-315)
Glycerol aminobenzoate (260-315)
ADVANTAGES : Water and perspiration
resistant.
DISADVANTAGES : Contact and photocontact allergy (PABA > Esters), PABA
stains (Esters stain rarely).
BENZOPHENONES
Their primary protective range is found in the UVA range (320-400 nm).
Oxybenzone
(270-350 nm)
Dioxybenzone (206-380)
Sulisobenzone (250-380)
ADVANTAGES : Less allergenic
than PABA, do not stain.
DISADVANTAGES : Less water resistant than PABA (so their bases in the
sunscreens are thicker and less cosmetically acceptable).
CINNAMATES
Derivatives of Cinnamon, their primary protective range is found in the UVB range (290-320 nm).
Octyl
methoxycinnamate (280-310
nm)
Cinnoxate (270-328)
ADVANTAGES : They do not
stain, good protectors.
DISADVANTAGES : Poor water resistance (frequent reapplications), may cause
cross reaction allergy in persons allergic to Balsam of Peru, tolu balsam,
coca leaves, cinnamic oil.
SALICYLATES
Their primary protective range is found in the UVB range (290-320 nm).
Homosalicylate
(290-315 nm)
Octyl salicylate (260-310)
Triethanolamine salicylate (269-320)
DISADVANTAGES : Octyl and triethanolamine may cause photocontact dermatitis more frequently than homosalicylate, so they are used less frequently.
DIBENZOYLMETHANES
The best UVA protectors,
their protective range is found in the UVA range (320-400 nm). They offer
no protection from UVB.
Tert-butylmethoxydibenzoylmethane
(310-400 nm)
4-Isopropyldibenzoylmethane (310-400)
DISADVANTAGES : Although isopropyl-DBM has been used in Europe for several years, it has not been approved for use in the USA, because of the high incidence of contact dermatitis reactions.
OTHER SUNSCREEN AGENTS
Methylanthranilate
(200-380) :
With low-level broad spectrum coverage, is added to many sunscreens to
augment protection.
Octocrylene (287-323)
Etocrylene (296-383)
VEHICLES
& PRESERVATIVES THAT CAN CAUSE
CONTACT or PHOTOCONTACT DERMATITIS
| Avocado oil | t-butyl alcohol | methyl-parabens | phenyldimethicone |
| solvent red 1 | solvent red 2 |
triethanolamine stearate | benzyl alcohol |
| cetylstearyl alcohol | sorbitan sesqoiolate | imidazolidinyl urea (Germall 115) | Kathon CG |
| glyceryl monostearate | 6-acetoxy-2, 4-dimethyl-m-dioxane | carbowaxes | ethyl alcohol |
| glycerol | isopropyl alcohol | isopropyl myristate | petrolatum |
stearyl alcohol |
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Sunscreen Formulations available in Greece
(coming...Στα Ελληνικά !)
1. Melvin L. Elson, ed. Evaluation
and Treatment of the Ageing Face. Springer - Verlag, NY, 1995.
2. O' Donoghue MN. Sunscreen: one weapon against melanoma. Dermatol Clin.
1991;9:789-793.
3. Dromgoole SH, Maibach HI. Contact sensitization and photocontact sensitization
of sunscreening agents. In: Sunscreens: Development, Evaluation and
Regulatory Aspects, NJ Lowe, NA Shaath, eds. Marcel Derker, NY, 1991.
| (c)
Organised by Constantinos D.
Verros, MD |
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