so they should be applied at least 30 minutes prior to going out in the sun. Sunscreens absorb ultraviolet [UV] light in certain wavelengths. The UVA rays can cause long-term effects and contribute to photoaging and wrinkles. UVB rays are responsible for short-term effects like sunburns. UV light can easily degrade sunscreen, so its crucial to reapply every few hours for maximum effectiveness. Avobenzone[Butylmethoxydibenzoylmethane], Octylmethoxycinnamate and Octocrylene are common ingredients in many chemical blockers these days.
In contrast, sun blocks, also known as physical blockers, primarily sit on top of the skin and reflect the suns UV rays prior to its penetration into the skin. The earliest physical blockers included zinc oxide or titanium dioxide [think of the white paste on a lifeguards nose]. Todays formulations are micronized, allowing more even coating and a lighter feel on the skin. Because sun blocks do not absorb into the skin, they are an ideal choice to use on children and infants aged older than 6 months. Many products on the market do contain both physical and chemical blockers.
UVA [ultraviolet-A]: long- wave solar rays of 320-400 nanometers [billionths of a meter]. Although less likely than UVB to cause sunburn, UVA penetrates the skin more deeply, and is considered the chief culprit behind wrinkling, leathering, and other aspects of photoaging. The latest studies show that UVA not only increases UVBs cancer-causing effects, but may directly cause some skin cancers, including melanomas.
UVB [ultraviolet-B]: short-wave solar rays of 290-320 nanometers. More potent than UVA in producing sunburn, these rays are considered the main cause of basal and squamous cell carcinomas as well as a significant cause of melanoma.
UVC [ultraviolet-C]: shortest from the sun, usually does not reach the earths surface being absorbed by the ozone layer above the earth. Occasionally articles are written on the ozone depletion and the possible exposure to UVC where only a brief exposure can cause light sunburn. Prolonged exposure to UVC is considered fatal.
SPF [sun protection factor]: Solarin 60 has sun protection factor [SPF] 60. The SPF of any sunscreen is calculated as
SPF= Time needed to produce sunburn with sunscreen / Time needed to produce sunburn without sunscreen
The SPF of any sunscreen reflects the products screening ability only for UVB Rays. It means that SPF is not a measure of UVA rays. However, many sunscreens products with ingredients such as titanium dioxide, zinc oxide, Octylmethoxycinnamate and Butylmethoxydibenzoylmethane also provide protection against UVA rays. These sunscreen products, apart from having their own SPF, are labelled as Broad spectrum sunscreens to indicate their protection ability against UVA as well as UVB.
The Japanese have a rating system which reflects a sunscreens ability to protect specifically against UVA. This rating is known as Protection Factor of UVA or PFA. According to this system Solarin 60 has PA ++ grading. This grading comes from Japanese Cosmetic Industry Association [JCIA] and represents a roughly UVA protection factor. PFA is calculated as:
PFA= MPPD of protected area / MPPD of unprotected area
Where MPPD is Minimum Persistent Pigmentation Darkening [2 to 4 hours after exposure to UVA] Unlike SPF which can range from any number between 2 to 60 or even higher, the PFA grading has been assigned following three categories:
PA+ = PFA >2 - <4
PA++ = PFA >4 - <8
PA+++ = PFA >8
Sun Effects on Skin Information / Repeated Sun Exposure is responsible for
Generic name: Avobenzone: butyl methoxydibenzoylmethane
Range of UV spectrum covered: UVA [both UVA-1 and UVA-2]
Wavelengths covered: 310-400 nm, which covers all of UVA
Stability:Avobenzone degrades in the sunlight, which leads to loss of protective effect. The rate of degradation can be reduced by photostabilizers. However, photostabilizers may increase the risk of skin irritation.
Summary:Abobenzone is one of the very few chemical sunscreens with good coverage of UVA spectrum. Abobenzone is relatively nonirritating, although, as with many skin care ingredients, the possibility of low-level topical or systemic toxicity with long-term use remains unresearched. Abobenzone degrades in sunlight [especially if mixed with inorganic sunscreens] and loses effectiveness over time. Development of stabilized and microencapsulated versions of avobenzone is promising and may reduce the above drawbacks.
Details:Avobenzone is an oil soluble chemical agent capable of absorbing light throughout the entire UVA spectrum. It is one of the very few comprehensive chemical UVA sun blocks in widespread use. Avobenzone appears to be relatively non-toxic and rarely causes skin irritation. However, as with many synthetic chemicals, it is unclear whether avobenzone or its degradation products may produce low-level toxicity with long-term use.
Generic name: Octylmethoxycinnamate: octinoxate
Range of UV spectrum covered: UVB
Wavelengths covered: 280-320 nm
Stability: When exposed to sunlight Octylmethoxycinnamate is converted into a less UV absorbent form [from E-octyl-p-methoxycinnamate into a Z-octyl-p-methoxycinnamate]. This conversion can be partly prevented by certain other UV blockers, particularly bemotrizinol [Tinosorb M].
Summary: Octyl methoxycinnamate [octinoxate] is a chemical sun blocking agent that absorbs ultraviolet radiation in UVB range. When exposed to sunlight octyl methoxycinnamate is converted into a less UV absorbent form, which reduces its effectiveness. This conversion can be partly prevented by certain other UV blockers.
Generic name: Titanium dioxide: Titanium oxide: TiO2
Range of UV spectrum covered: UVA [better covers UVA-2 than UVA-1], UVB
Wavelengths covered: good uniform coverage between 290-350 nm: insufficient coverage between 350-400 nm, especially in microfine/nanoparticle forms
Stability: Regular titanium dioxide is highly stable under most conditions. However, it has some photocatalytic activity [i.e. promotes reactions between other chemicals], especially in direct sunlight. Titanium dioxide nanoparticles appear to have much greater photocatalytic activity than regular titanium dioxide powder and might trigger formation of harmful free radicals when exposed to sunlight. Most manufacturers of titanium dioxide nanoparticles coat them to reduce or eliminate such effects.
Summary: Titanium dioxide is a physical sunscreen protecting against UVB and short UVA light. It has a long history of seemingly safe use and is not irritating. Its disadvantages include unsightly whitish tint and insufficient protection against long UVA. It may also help generate harmful free radicals via photocatalytic mechanism when exposed to sunlight. These effects may not have significant impact in topical use but the issue needs to be researched. Titanium dioxide is usually combined with chemical UVB and UVA blockers and/or zinc oxide.
Details: Titanium dioxide is a physical sun blocking agent that work primarily by reflecting/absorbing ultraviolet light. It bocks UVB and short UVA [320-340 nm]. Titanium dioxide is less effective against long UVA [340-400 nm]. Hence, in regard to the range of protection, titanium dioxide is inferior to zinc oxide, another popular physical sun block. Titanium dioxide has a long history of safe use as a sun block and cosmetic ingredient. It is not irritating and more compatible with sensitive skin than chemical sunscreens. However, unlike zinc oxide, it is not an anti-irritant or skin protector. Furthermore, it has significant photocatalytic activity and may promote formation of free radicals when exposed to sunlight. However, since it is not absorbed into the skin, this effect may not be an issue in topical use on unbroken skin. More research is required. The main complaint about titanium dioxide-based sunscreens is that they leave unsightly white residue. In fact, titanium dioxide creates stronger whitish tint than zinc oxide at comparable concentrations. This problem has been partly addressed by the advent of titanium dioxide nanoparticles as a sunscreen agent. Titanium dioxide nonoparticles have different optical properties and tend to produce much less whitish tint than regular powdered titanium dioxide. Yet, early research indicates that titanium dioxide nanoparticles retain the capacity to protect from UVB and short UVA light.
Generic name: Zinc oxide: Zn0
Range of UV spectrum covered: UVA, UVB
Wavelengths covered: good uniform coverage between 290-400 nm, and some coverage up to 700 nm
Stability: Regular zinc oxide is highly stable under most conditions: minimal reactivity may occur, especially in direct sunlight. However, zinc oxide nanoparticles are far more reactive/catalytic than regular zinc oxide powder and might promote the formation of harmful free radicals when exposed to sunlight. Most manufacturers of zinc oxide nanoparticles coat them to reduce or eliminate such effects.
Summary: Regular zinc oxide is one of the most broadly effective, established and safe sun blocking ingredients available. Also, it is difficult to achieve high SPF [UVB protection measure] with zinc oxide alone. Therefore, in high SPF sunscreens, it is generally combined with chemical UVB blockers.
Details: Zinc oxide is a physical sun blocking agent that works primarily by reflecting/scattering ultraviolet light. It has a broad range of effectiveness, covering UVB as well as both short [320-340 nm] and long [340-400 nm] UVA. Regular zinc oxide also blocks visible light up to wavelengths 700 nm, whereas zinc nanoparticles block only up to 380 - 400 nm, depending on the specific formulation. As a single ingredient, zinc oxide is the broadest range sunscreen on the market. Zinc oxide has a long history of safe use. It is not irritating and compatible with sensitive skin. In fact, zinc oxide is a skin protectant and anti-irritant, and is widely used in treating various forms of dermatitis/skin irritation, including diaper rash. The main complaint about zinc oxide-based sunscreens is that they may leave unsightly white residue. In fact, the concentrations of ordinary forms zinc oxide required for high degree of protection against the full range of UVA and UVB inevitably produce some whitish tint. This problem has been partly addressed by the advent of zinc oxide nanoparticles as a sunscreen agent . Zinc oxide nanoparticles have different optical properties and tend to produce much less whitish tint than regular powdered zinc oxide. Yet, early research indicates that zinc oxide nanoparticles retain the capacity to protect from UVA and UVB light.
Generic name: octocrylene
Range of UV spectrum covered: UVB, short UVA but not long UVA
Wavelengths covered: 290-350 nm
Stability: Highly stable, does not degrade in sunlight. Protects other UV blocking agents from UV-induced degradation.
Summary: Octocrylene is an oil soluble, water resistant absorber covering UVB and short UVA. It is a relatively weak sunscreen, inadequate when used alone. On the other hand, octocrylene is very stable and it both protects and augments other UV absorbers while improving their uniform skin coating.
Details: Octocrylene is an oil soluble, water resistant absorber covering UVB and part of UVA range called short UVA. However, even in the parts of the spectrum where octocrylene absorbs UV radiation, it is a relatively weak sunscreen. Used alone it is inadequate for either UVB or UVA protection. On the other hand, octocrylene is very stable and it both protects and augments other UV absorbers while improving their uniform skin coating.
Dimethicone Fluids are linear Polydimethylsiloxanes [CAS# 63148-62-9] that range in viscosity from 5cSt to 20cSt [centistokes]. These fluids are clear, colourless and essentially odourless. Dimethicone Fluids are is characterized by their low viscosity [close to water], excellent lubricity, soft-emollient feel, low surface tension [high spreadability], and low pour point [- 90°C]. Unlike viscosities < 3cSt, these fluids will not evaporate at room temperature and offer much higher thermal stability.
Dimethicone Fluids are used in a wide range of personal care products, providing a soft velvety feel when applied to both hair and skin. They provide a hydrophobic, protective, but breathable barrier to the skin [allows skin to perspire]. Low Viscosity Dimethicone Fluids provide lubricity without the greasiness of higher viscosities. They are particularly effective when blended with Cyclomethicone fluids. Applications include: skin cream lotions, bath oils, suntan lotions, nail polishes, antiperspirants, deodorants, hair sprays and other beauty and hair care products.
Unfortunately, vitamin C is relatively unstable. A variety of approaches have been used to try to stabilize vitamin C in water solution.
Most vitamin C derivatives on the market, including ascorbyl palmitate and magnesuim ascorbyl phosphate, consist of the ascorbic acid fragment [ascorbyl] and a fragment of another acid [e.g. palmitate or phosphate]. Recent research indicates that new vitamin C derivatives consisting of multiple chemical fragments bound to a single ascorbic acid fragment may work even better. These new derivatives are more stable compared to both vitamin C and older derivatives. Furthermore, some of these newcomers [particularly the so-called tetrasubstituted lipophilic ascorbates] also appear to be more powerful boosters of collagen synthesis. Even though relatively few skin care products currently on the market contain these new compounds, they may become widely used as more evidence of their benefits accumulates.
Vitamin E is a fat soluble antioxidant. In living systems, vitamins C and E can regenerate each other and thus potentiate each others antioxidant effects. While the capacity of vitamin E to protect vitamin C from oxidation in a water solution is relatively modest, vitamin E enhances the antioxidant effects of vitamin C when they are co-applied to the skin. Therefore, even if some of the vitamin C in a product is degraded, the remainder works better in the presence of vitamin E. Studies indicate that the combination of vitamins C and E provide better protection from UV-induced damage than either vitamin alone. On the other hand, vitamin E appears to have little effect on the ability of vitamin C to stimulate the synthesis of collagen.
Apply liberly over the entire face, neck and other areas that are expose to sun light at least thirty minutes before sun exposire or as directed by your dermatologist or costmetologist.
improve quality of skin, leave the skin supple and healthy
Store in a cool dry aea [below 30 Degree C] away from direct sunlight.