Abstract

Sunlight is a despite of source of life and energy creating major health challenges like sunburn, pigmentation, wrinkles, dermatitis, urticaria, ageing, immune-suppression and number of skin cancers too. Sun protective clothes and or sunglasses provide insufficient and a less convenient approach to get rid of all these health hazards. So, sunscreen protection is popular mean among various regions of world. Present article has summarized types and classification, regulations, terminologies, evaluation methods, labelling, dosage and controversies of sunscreens. Natural chemical classes like phenolics, carotenoids, Vita- mins, oils are also discussed.

Introduction

I. INTRODUCTION

Cosmetics are described as ‘‘articles supposed to be rubbed, Poured, sprinkled, or sprayed on, delivered into, or otherwise Carried out to the human frame or any component thereof for cleansing, beautifying, selling attractiveness, or changing the appearance”. Among the generally used cosmetics are sunscreens. These are formulations which might be carried out onto the pores and skin floor to Defend it from the dangerous results of ultraviolet (UV) mild. Repeated publicity of the pores and skin has been related to a excessive risk Of growing pores and skin cancers. According to most cancers studies USA, eight out Of 10 instances of cancer might be avoided thru an under status of the dangerous results of daylight and a way to defend oneself from the dangerous rays .Of   worries to Fitness businesses round the sector is the growth in excursion sunbathing in addition to the usage of synthetic UV reassets to result in pores and skin Tanning amongst younger whites looking for a darker pores and skin  Sunrays encompass an array of wavelengths stages that fluctuate in Frequency and their electricity profiles.

The suns electromagnetic Spectrum includes cosmic rays, gamma rays, X-rays, UV rays, Microwaves, and radio waves in lowering order of electricity. Among Those cosmic, gamma and X rays are correctly filtered out of the Earth via way of means of the surroundings and consequently gift no capability for Inflicting harm. It is, however, noteworthy that they may be the Deadliest and publicity could result in failures of epic proportions. The UV rays can penetrate the earth’ surroundings as can the rest of the decrease electricity spectrums. Microwaves and radio waves are Now no longer of clinical significance as pertains to inflicting pores and skin harm.

The Recognition of this newsletter is as a consequence the UV spectrum of mild .The UV mild is a part of the seen mild and spans the wave duration from a hundred to four hundred nm as proven in Fig. 1 below. The UV spectrum is similarly divided into three; 290–320 nm (UVB) and 320–400 nm (UVA) . UVC Occupies a 100- 290 nm of the spectrum; however, it’s far of no clinical Significance given that it’s far completely filtered out via way of means of the ozone layer. UVB Triggers the manufacturing of melanin pigment and stimulates the pores and skin Cells to supply a thicker dermis, ensuing in an enduring tan. It is likewise the number one purpose of sunburns.

The UVA mild activates Melanin already at the dermis to supply a short-time period tan. It Penetrates a great deal deeper into the pores and skin than UVB and might purpose long Time period harm to the pores and skin in addition to pores and skin ageing characterized via way of means of loss of elasticity and wrinkling. Its results happen a great deal later compared to the results of UVB which can be acute. sunscreens additionally known as sunblock act with the aid of using reflecting and scattering the UV mild thereby defensive the pores and skin. Common examples of mineral sunscreens encompass titanium Dioxide and zinc oxide. Inorganic filters gift a minimal potential for allergic sensitization and excessive photostability and are therefore extra suitable for human beings with touchy pores and skin.

However, their reflective residences might also additionally cause Immoderate shine and a whitish aspect, proscribing their exceptional use to formulation because of low beauty acceptance. The performance of inorganic filters is associated with the dimensions and dispersion in their particles. Currently, present formula incorporates each chemical and mineral sunscreen. Different formulations exist including Creams, gels, sprays, and oils.                                        

II. IDEAL CHARACTERISTICS OF SUNSCREEN

1. Must absorb a broad range of UV rays causing sunburn 
2. Must be stable in the presence of sunlight 
3. Should be able to provide complete protection for skin 
4. Should be safe effective, chemically inert, at low concentration 
5. Should not cause irritation, sensitization and toxicity 
6. Should not stain Filtering 
7. Activity against UVB and UVA radiation 
8. Anti-oxidant and reactive oxygen species scavenging property
9. Anti-mutagenic property 
10. Anticancer property
11. Booster effect I

A. Merits of Sunscreen

1. Helps to prevent sunburn and premature aging
2. Protects from the sun as soon as it is applied.
3. Lasts longer when in direct UV light.
4. Better for those with heat-activated skin[redness]. 
5. Offers protection against UVA and UVB rays. 

B. Demerits of Sunscreen

1. It is an expensive product.
2. Can create an occlusive film which results in perspiration.
3. Can be less protective if not applied accurately and generously.
4. Can cause white drips to show on the skin when sweating.
5. Sunscreen can cause stickiness in some skin types. 

III. IMPORTANCE OF SUNSCREEN

UV radiation is essential for human health because it aids absorption in the intestine for the production of calcium, phosphorus and vitamin D3. On the other hand, this radiation also damages our health, acting directly on DNA, RNA proteins, lipids and thus causing possible carcinogenic effects. The most effective way to protect the skin harmful UV radiation is the local application of any active molecule with UV radiation absorptive or reflective properties. Therefore, the importance of sunscreen products has increased current scenario.  Using sunscreen is one of the best – and easiest – ways to protect your skin and appearance and health at any age. With regular use, sunscreen helps prevent sunburn, skin cancer and premature aging. To make sunscreen a part of your daily routine, dermatologist Anna Chien addresses common concerns.

Figure; Sunscreen Agent

1. Inorganic (physical blockers): These are patching that scatter and reflect UV shafts back to the terrain. They act as a physical hedge to indent ultraviolet and UV light. The two primary inorganic UV pollutants are Zinc oxide (ZnO) and titanium dioxide TiO2) white patches which used in the ornamental and pharmaceutical diligence. The current agents are ZnO, TiO2, calamine, ichthammol, talc, and red veterinary petrolatum. Although they’re generally less poisonous, more stable, and safer for mortal than those of organic constituents, they’re visible due to white colour remainders left on the skin and can stain clothes.
2. Organic (chemical absorbers): Organic UV pollutants similar as benzophenones, absorb UV radiation with excitation to a advanced energy state. These are generally sweet composites linked with a carbonyl group. They’re astronomically classified into three orders grounded on the range of protection; UVB (290 – 320 nm) and UVA (320 – 400 nm) and broad diapason sunscreens that cover the entire spectrum (290 – 400 nm). Particularly, some organic pollutants (e.g., PABA, PABA derivations, and benzophenones) show considerable negative goods, including eczematous dermatitis, burning sensation, and increased threat of skin cancer. 
3. Natural/ Systemic (chemical absorbers): Natural chemicals like polyphenols (flavonoids, tannins), carotenoids, anthocyanidins, many vitamins, triglyceride canvases, unpredictable canvases from vegetables, fruits, medicinal factory corridor (leaves, flowers, fruits, berries), algae and lichens are more effective over synthetic chemicals which is due to their longterm salutary goods especially against free radical generated skin damages along with UV- shafts blocking. These are sunscreens that are absorbed into the body and accumulate in the skin swinging protection from the UV shafts.

A. Why we use Sunscreens? 

Too much-unprotected sun exposure leads to 

1. Premature skin ageing
2. Sun burn 
3. Skin cancer

Figure No 1: Sun Burn

B. Light Protection Mechanism

 Photooxidation damage caused by UV rays reaches the skin capillaries, epidermis and dermis and cause depletion of enzymatic and non-enzymatic antioxidants in the dermis cornea, epidermis and dermis. Photooxidation of existing melanin and its precursors occurs, resulting in an immediate and continuous darkening of the pigment. Sunscreen works by preventing and minimizing the harmful effects of ultraviolet rays has been shown to increase skin tolerance after exposure to sunscreen skin to UV radiation. They work by two mechanisms: Diffusion and reflection of UV energy from the mineral on the surface of the skin based on an inorganic substance sunscreen works by this mechanism and they provide a coating that blocks the sun’s rays penetrate the skin. 

Figure No. 3: light Protection Mechanism

IV. FORMULATION OF SUNSCREEN

 Formulation of sunscreen entails 4 important steps; selection of the goal product design, desire of lively components and the Shipping automobile observed through product optimization as proven. The number one goal of the components professional is to develop a product that paperwork a non-stop movie at the pores and skin. Penetration of the natural components into the pores and skin have to be minimized [18]. Organic sunscreens are formulated as creams and mild ointments. On application, they shape a skinny movie at the pores and skin surface that presents UV safety. Other formulations encompass oils, gels, Emulsions, mousses (fluid emulsions), aerosols, sticks, and powders. Inorganic sunscreens are greater tough to formulate due to Their particulate nature. Traditionally, they have been formulated as lotions that have been sticky, oily and ugly to use. Anonymization Has allowed spray formulations that shape a translucent layer on the pores and skin that presents safety whilst preserving the aesthetics of the product. Currently no nanosized spray formulations of sun monitors had been accredited for registration due to protection concerns as those nanoparticles can be inhaled and consequently cause gadget toxicities. Inorganic sunscreens are formulated as pastes, emulsions, sprays, and ointments. Particle engineering approaches Which include micritization and anonymization of the debris are Finished to growth the cultured price of the products . The protection and comfort of the person manual the formulation approach. Any substance with ability pores and skin irritancy and ability allergens needs to be avoided. Like different pores and skin products, formulation calls for the inclusion of adhering retailers to sell pores and skin adsorption in addition to the suitable automobile into which the lively Substance is dispersed. Patents play an critical function withinside the development technique, and cautious attention should be taken before Embarking on product development. Among the demanding situations and worries related to topical Sunscreens formulations contain the photostability of natural filters, broadening the effectiveness spectrum and parameters, incorporating energetic ingredients, enhancing beauty and sensory Elements, individualizing vehicles. The best sunscreen formula Have to think about elements such as performance for the meant use, the scope of safety spectrum (UVA and UVB), protection and tolerability for topical use, stability, no staining of clothes, good enough cosmetics, best fragrance, resistance to Water, spreadability, excessive extinction coefficient, and affordable Cost. Sunscreen formulations encompass the primary sunscreen agents, Excipients unique to the formula kind such as an appropriate solvent or automobile systems. The contents choice is determined with the aid of using the meant use and the physicochemical nature of the ingredients. Purified water utilized in product formula is prepared thru opposite osmosis and different set up techniques of Purifying water for commercial us . The maximum not unusual place sunscreen actives; titanium dioxide, zinc Oxide, avobenzone, benzophenone 8, octocrylene, and oxybenzone Are used. To range the quantity of solar safety, the extent of the energetic factor is adjusted. Lademan and organization set up synergy among natural and natural sunscreens and demonstrated Advanced efficacy of merchandise comprising of the 2 as compared to the ones containing best natural or inorganic sunscreens. The FDA prescribes the most allowable concentration of every factor in addition to the impurity content. It is common to discover sunscreen being co-formulated with different pores and skin Merchandise for cost addition A rationally designed and advanced product complements the compliance of the customers while affording the important safety towards the ultraviolet-induced Pores and skin damage (Xu et al., 2016). In the final many years, the adoption of the Quality with the aid of using Design (QbD) idea has been endorsed with the aid of using the main regulatory Authorities. Embracing this technique consists of a scrupulous scientific layout of the product, cautious choice of substances and process parameters to make sure the success of a predefined Product excellent profile.

The formulator develops a Quality Target Product Profile (QTTP) that specifies the Favoured physicochemical and overall performance attributes of the solar screen. They then continue to outline the Critical Material Attributes (CMAs) and technique parameters required to acquire the QTTP so Defined Risk evaluation is performed to predicament regions which could save you success of the favoured product Excellent and suitable measures are undertaken to cope with these Ability risks. To complement success of the favored product Excellent, use of layout of experiment (DoE) equipment may be a valuable Manual in optimizing the ideal attributes of the sunscreen.

V. EVALUATION OF SUNSCREEN

A. Physical Parameters

1. Colour: The colour of formulation was checked manually and observed. 
2. Odour: The Smell of Formulation was checked by applying preparation on hand and feel the fragrance.
3. Appearance: Visually checked the appearance of the formulation.  

B. Determination of pH: 

The pH of sunscreens was determined using a digital pH meter. pH was measured after 1 g of the formulation was dissolved in 100 ml of newly prepared distilled water for 2 hours. The purpose of this study was to guarantee that the pH of the produced herbal sunscreens is similar to the pH of the skin after 24 hours of use. The results were triple-checked, and S.D. was recorded. 

C. Determination of Viscosity

The Brookfield viscometer was used to test viscosity, with the proper number of spindles Selected. A 50 ml beaker was used to hold 50 g of preparation until the spindle groove was Dipped and the rpm was set. Sunscreen viscosity was measured at 5, 10, 20, 50, and 100 Rpm.

The viscosity was computed using the factor obtained from the reading. 

D. Spread ability

The spread ability of sunscreens determined their therapeutic efficiency. The appropriate amount of sunscreen was applied between two slides, and under specified Load directions, and the two sides took the time in seconds to slide off. Spreadability was Defined as the amount of time it took to separate two slides in less time. 

The formula for calculating it is: ???? = ???? × ???? /t

 Where,

 M = weight tied to the upper slide

 L = length of glass slide

 T = time taken to separate the slides [24]

Conclusion

Due to increased awareness of the need for protection from harmful UVA and UVB rays, there is a significant market potential for sunscreen chemicals, whether they are synthetic, natural, or a combination of both. A minimum ideal requirement for a sunscreen product would be photo stabilized, uniform, UVA/UVB protection with a high SPF. However, natural chemicals such as polyphenols (flavonoids, tannins), carotenoids, anthocyanidins, certain vitamins, fixed oils, and volatile from vegetables, fruits, medicinal plant parts (leaves, flowers, fruits, berries), algae, and lichens are more effective because of their long-term beneficial effects, particularly against free radical generated skin damaging in addition to blocking UV rays. These sunscreens with natural chemicals added could offer reasonably priced, genuinely broad-spectrum protection with anti- oxidant, wound healing, antiinflammatory, and numerous other skin-benefiting properties.

References

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Copyright

Copyright © 2025 Dr. HiteshKumar Shantilal Agrawal , Mr. Omkar Navnath Mahale . This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.