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Sunscreen presentation

Sunscreen presentation. Supervised by : Dr.Ikhlas jarrar. Heba Isam Samira Farouq. Sunscreens.

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Sunscreen presentation

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  1. Sunscreen presentation Supervised by : Dr.Ikhlas jarrar Heba Isam Samira Farouq

  2. Sunscreens Sunscreens, also commonly known as sun cream, is a lotion, spray, gel or other topical product that absorbs or reflects some of the sun's ultraviolet (UV) radiation on the skin exposed to sunlight and thus helps protect against sunburn.

  3. Solar radiation UV spectrum (200-400 nm) The visible spectrum (400-700 nm) Produce brightness of The sun The infrared spectrum (770-1800 nm) Produce the warmth of The sun UVC Short wave radiation ( 200-290 nm ) UVA Long wave radiation ( 320-400 nm ) UVB Middle wave radiation ( 290-320 nm )

  4. 1- UVA (320-400) * UVA can cause the skin to tan, and is weak in causing the skin to redden. * Erythrogenic activity is weak. * Uses: 1- used in tanning booths. 2- used in treatment of psoriasis. * Disadvantages: 1- responsible for photosensitivity rxn, photoaging and photodermatoses. 2- penetrates deeply in dermis. 3- UVA augments the cancerous effect of UVB rays.

  5. 2- UVB (290-320) * Causes the usual sunburn rxn. * Stimulates tanning. * Uses: small amounts are required for normal vitamin D synthesis. * disadvantage: 1- erythrogenic and melanogenic activity is the highest. 2- Responsible for inducing skin cancer.

  6. 3- UVC (200-290) * Doesn't reach the earth surface because most of it is absorbed by the ozone layer. * may be found as a source in germicidal and mercury arc lamps

  7. Sunburn & suntan 1- sunburn is a superficial burn involving the epidermis (which is rapidly repaired) and the old cells are being sloughed off in peeling process. The newly formed skin is thicker and offer protection for the lower dermis layer.

  8. sunburn • Normal sequence • (After mild to moderate UVR exposure) • 1- erythma occurs in(20-30 min) as • A result of oxidation of bleached melanin • & dilation of dermal venules. • 2- the initial erythma fades and true • Sunburn begins 2-8 hr. • 3- dilation of the arterioles result in: • A- increased vascular permeability • B- localized edema • C- pain Manifestations Range from mild to severe formation Of blisters and desquamation. If the effect is severe: 1- pain is developed 2-sweling & blisters 3- nausea, fever & chills

  9. Is the result of two process suntan 1- oxidation of melanin ( which is present in the Epidermis) 2- stimulation of melanocytes to produce More melanin. Melanin production, the melanocyte Introduce the pigment to the keratin Producing cell which become darkened Keratin. Tanning increase tolerance to additional Sunlight & reduce the burning

  10. Factors affecting exposure to UVR 1- time of day and season. 2- altitude. 3- enviromental factor. 4- predisposing factors.

  11. Drug induced photosensitivity reactions Types Photoallergic reaction Phototoxic reaction

  12. 1.PHOTOALLERGY REACTION Occurs when light makes a drug become OR the drug act as Hapten (photo allergen) Antigenic

  13. These reactions also require previous contact wit offending drug . photo allergy reactions are relatively RARE & are associated more frequently with topically applied agent than oral medication . • Occurrence is • 1. not dose related . • 2.patient is usually cross-sensitive with chemically related compounds.

  14. Photoallergic rashes • Are most prominent on light exposed sites • 1. face . • 2.neck. • 3.forearms. • 4. back of hands. • They usually occure after An incubation period of 24-48 hr of combined drug & sun exposure. As an intensly pruritic eczematous dermatitis (sever rash)

  15. 2.Phototoxic reaction Occure when light alter adrug to toxic form wich result in tissue damage that is independent of allergic reaction . Tissue damage

  16. Phototoxic rxn occurrence

  17. Implicated drugs that cause photo allergy &phototoxic

  18. prevention • - standard sunscreen don’t always prevent photosensitivity reactions caused by drug. UV light > 320 nm ( UVA ) induce photosensitivity So a chemical or physical sunscreen must cover this spectrum.

  19. Photodermatoes • Photodermatoes are skin conditions that are triggered OR worsened by light withen spesific wavelengths. • These include :

  20. photoaging • Skin condition that is NOT merely an acceleration of normal aging. • UVA is thought to be involved • The skin appears

  21. sunscreen agents • Application & general information • All exposed area should be covered evenly & liberally 2 mg/cm² . • Requires ~ 1 ounce / total body application for an average size adult . • Optimally 30 min before sun exposure why??? To allow it to penetration & binding to the skin .

  22. Substantively Things tend to remove sunscreen & may increase the need for reapplication :

  23. Protection Factors should be noted to determine level of protection :

  24. Sun protection factor (SPF) SPF gives the consumer a guide for determining how the product will protect the skin from UV rays .

  25. Derivation SPF = MED of protected skin / MED of unprotected skin MED ( minimal erythma dose ) is the amount of solar radiation needed to produce minimal skin redness. e.g. Person who usually gets red after 20 min in sun Want to stay in the sun for 2 hr (160 min) He should apply a sunscreen SPF of 6 SPF= 120/20 = 6 SPF 6 should provide adequate coverage .

  26. Until now , there has been no generally accepted comparable term that measures UVA protection . • People my stay longer when they use sunscreen product that have higher SPF values • If inadequate UV protection is provided these individuals may expose themselves to vry high amount of UVA.

  27. Proposed FDA UVA protection system

  28. Consumer friendly rating system • Proposed by FDA regarding their level of UVA protection in product : • a). One satr :low UVA protection . • b). Tow stars : medium UVA protection . • c). Three stars :high UVA protection . • d). Four stars : highest UVA protection . • If approved , additional warning would be required on sunscreen products

  29. Its important to decrease UV exposure by

  30. Skin cancer prevention • Sunscreen application has been shown to prevent sqamous cell carcinoma . • But its not absolutly confirmd that their use prevents melanoma. • Some studies have found that indivduals who regulary use sunscreen have higer risk of melanoma cancer Perhaps because they can stay out in sun longer before burning & thus experience longer on sun exposure

  31. Sunscreen sensitivity • Some people may be hypersensitive to sunscreen agents . • Discontinue use if signs of irritation or a rash occur. • Contact dermatitis may occur with some of these agents. • If sensitive to benzocaine , procaine , sulfonamides or thiazides avoid PABA or PABA esters .

  32. Specific information (1) . Don't use sunscreen on infant < 6 months of age ( due to absorption ) (2) .Don’t use a product with an SPF < 4 on children < 2 years . ( will not provide adequate protection ) (3). Recommended sunscreen products that are broad spectrum sunscreen ( that block both UVA & UVB )

  33. Sunscreen agent

  34. Physical sun block • Are opaque formulations That reflect & scatter 99% of both UV andd visible (290-700nm) . These sun block are less cosmetically acceptable than chemical sun block agent , because they have greasy appearance . But they maybe useful for protecting small areas Useful for photosensitization protection.

  35. More dilute titanium dioxide & microfine and transparent form of zinc oxide are more cosmetically appealing . • Red petrolatum covers a lesser spectrum ( 290 _ 365 nm )

  36. Chemical sunscreens Act by absorbing a specific portion of UV light spectrum to keep it from penetrating the skin They categorized on the basis of their spectrum of UVR blockage & chemical classification :

  37. Absorb UVB rays 1. PARA & PARA esters 2. Salicylates : P-aminobenzoic acid Ethyl dihydroxy propyl PABA Glyceryl PABA Padimate O (octyl dimethyl PABA)

  38. 3. Cinnamate 4.Benzophenones : absorb also UVA , protective in photosensitivity rxn . dioxybenzone oxybenzone

  39. 5.Other sunscreen agents It covers just UVB 290-320nm Coverage decrease At 370nm . Photosensitivity may not Completely prevented in 370-400nm

  40. Otc sunscreen product • Most sunscreen products on the market contain combination of tow or more of classes of chemical sunscreen agents . • To get adequate UVA protection choose a product with avobenzone or a product with titanim dioxide or zinc oxide . • New agent ecamsule incorporated into a combination product avobenzone and octocrylene was approved by FDA in 2006 this protect against both UVA &UVB .

  41. Any question ???

  42. Thanks for your attention

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