Sunscreen
Sunscreen is a type of lotion, spray, gel, or foam that absorbs into the skin and reflects the ultraviolet rays of the sun.It helps to protect the skin from sunburn.
It is also known as sunscreen cream, sunscreen lotion, suntan lotion, and sunblock.
The main purpose of sunscreen is to either absorb the sun's radiation or scatter sunlight effectively.
There are three types of ultraviolet rays that are most harmful to humans that are;
Ultraviolet (UVA) – These radiations penetrate into the skin and can cause damage to the cell membrane.
Ultraviolet (UVB) – These rays can also cause skin cancer and can damage the cornea as well as the lens of the eye.
Ultraviolet (UVC) – These radiations are generally absorbed by the earth’s atmosphere so, it is not considered harmful to the skin.
Therefore, sunscreen is a cosmetic formulation that is used to protect the skin from the ultraviolet (UVA, UVB) rays of the sun.
Active use of sunscreen can also be slow or temporarily prevent the development of wrinkles.
The preparation of sunscreen is divided into three categories such as preventive, stimulatory, and therapeutic.
Characteristics Of Sunscreens
1) It should have broad spectrum activity. It should absorb erythmogenic radiations in the range of 290 - 320 nm without its breakdown.2) It should be nonirritant, non-toxic, and non-sensitizing.
3) It should be non-comedogenic as well as hypoallergenic.
4) For tanning effect it should allow the full transmission of radiation in the range of 300 - 400 nm.
5) It should have good solubility characteristics in a suitable vehicle.
6) It should be not volatile, and mild or odorless.
7) It should be stable to heat and light.
8) It should be capable of retaining its sunscreen properties for many hours.
9) It should be neutral and also not stain the body.
Classification Of Sunscreens
1) Chemical (Organic) Sunscreens
These are the types of sunscreens that absorb UV light.Depending on their chemical structure, the organic UV filters are the active ingredients that absorb UV radiation within a particular range of wavelengths.
As the UV filter absorbs energy, it moves from lower energy levels to higher energy levels.
2) Physical (Inorganic) Sunscreens
These are the types of sunscreens that reflect the sunlight.These function by reflecting or scattering the UV radiation.
Their whitening effect is the main disadvantage which may be minimized by the use of ultrafine particles.
Benefits Of Sunscreen
1) It can minimize skin discolouration.2) It gives skin-lightening benefits.
3) It provides high UVA and UVB protection.
4) It helps in the prevention of brown spots and pigmentation.
5) It also provides protection against pollutants.
6) The use of sunscreen can also help to prevent melanoma and squamous cell carcinoma.
7) It may be effective in the prevention of basal cell carcinoma.
8) The sunscreen either slows or temporarily prevents the development of wrinkles.
What Is The Formulation Of Sunscreen?
There are many combinations of either synthetic or natural ingredients that are used in the formulation of sunscreen. A few active ingredients of sunscreens are as follows;1) Benzyl Salicylate And Salicylate Derivatives
It is the first sunscreen agent that provides UVB protection, but it does not provide UVA. Usually, it is used when combined with other substances. One of the compounds is known as homosalate, and other salicylate derivatives such as triethanolamine salicylate, para phenyl salicylate, benzyl salicylate, and phenyl salicylate are used as an agent of sunscreen.2) PABA (p-aminobenzoic acid)
This is the compound that is mainly used in many formulations. However, because many individuals experienced allergic reactions to it, this is not very often used.So, most of the sunscreens are PABA-free now.
3) Benzyl Cinnamate And Cinnamate Derivatives
This sunscreen agent was used earlier. This agent is used with other ingredients and it is an effective UVB blocker.4) Butyl Methoxydibenzoylmethane And Related Compound
This agent is also known as Parsol A. It is an effective UVA blocker.5) Anthranilates
These compounds absorb the UVA spectrum at 250-322 nm and are generally combined with the UVB agent to broaden the spectrum.6) Zinc Oxide And Titanium Dioxide
These compounds are used to block UV radiation because their formulation is opaque to light. Sunscreens that contain these compounds are generally white.Sunscreen Formulation
1) Sunscreen Lotion
| Ingredients | % |
|---|---|
| Methyl Salicylate | 9.0 |
| Glycerin | 3.0 |
| Borax | 2.0 |
| Alcohol | 15.0 |
| Water | 70.5 |
| Perfume | 0.5 |
Method
a) Take the water in a container and heat it.b) Dissolve the borax in it and add the salicylate into it.
c) Stir the solution until it dissolves.
d) Now, add perfume and mix it with alcohol.
e) After that add glycerin and stir this into the methyl salicylate solution
f) Finally, filter the solution and if required colour the solution then add a sufficient quantity of alcohol-soluble colourant.
2) Sunscreen Cream
Part A
| Ingredients | % |
|---|---|
| Coca butter | 6.0 |
| Petrolatum and lanolin alcohol | 3.0 |
| Stearic acid | 5.0 |
| Ethyl dihydroxy propyl PABA | 8.5 |
| Methyl gluceth-20 | 5.0 |
| Sesquisterate | 2.0 |
| Propyl Paraben | 0.1 |
Part B
| Ingredients | % |
|---|---|
| Aloe vera gel | 50 |
| Methyl gluceth-10 | 4.0 |
| water | 36.5 |
| Quaternium-6 | 1.5 |
| Triethanolamine | 1.0 |
Part C
| head 1 | head 2 |
|---|---|
| Methyl Paraben | 0.1 |
| Diazolidinyl urea | 0.3 |
| Fragrance and colour | q.s |
Method
a) Heat part A and part B separately at 70 °C.b) With continuous mixing add Part B to Part A.
c) Now, cool it up to 40 to 45 °C.
d) Then add diazolidinyl urea, preservative, and fragrance into it.
e) SPF is approximately 8 to 10.
List Of Best Sunscreen
Here is a list of some of the best sunscreens you may check out.
1) Oil-Free Sunscreen - Click Here
2) Daily Face Sunscreen - Click Here
3) Daily Tinted Sunscreen - Click Here
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