Sunprotection, sunscreen and its classification

Sunprotection, sunscreen and its classification, Regulatory bodies.

1. Subject: Cosmetics and Cosmeceuticals Presented by : Akash Vikal M. PHARM (Pharmaceutics) Presented to : Dr. Balakdas Kurmi HOD – “Quality assurance” Topic: Sun Protection, Sunscreens Classification and Regulatory Aspects

2. CONTENTS Sun protection Sunscreen and its classification Regulatory aspects

3. SUN PROTECTION Protection from sunlight is often equated with the use of sunscreens, but this approach is too narrow, and protection should consist of a package of measures: avoiding overexposure to sunlight, using sunscreens and wearing protective clothing. Solar ultraviolet (UV) radiation significantly influences the skin causing skin aging, sunburns, precancerous and cancerous lesions and immunosuppression.

4. Sun protection essential to skin prevents about 90% non-melanoma skin cancers and about 80% of melanomas are associated with exposure to UV radiation from the skin. UV radiation comprises of 3 categories depending on wavelengths are: UV-A: Ranges from 320 to 400 nm. Most responsible radiation for immediate tanning and darkening of the skin due to excess production of melanin in the epidermis.

5. UV-B: Ranges from 280-320 nm. Known as burning rays as they are 100 times more capable of causing sunburn than UV-A. UV-C Ranges from 200-280 nm. Filtered by stratospheric ozone layer so less effective and hazardous.

6. MECHANISM OF PHOTOREACTION Photo-oxidative mechanism depending on light-driven reactive oxygen species (ROS) generation is now accepted to cause skin photo-aging and photo-carcinogenesis . UV-A rays mediated photo-oxidative damage effectively reaches through The upper layers of skin into the human dermis and dermal capillary system Substantial protein and lipid oxidation occurs in human skin epidermis and dermis Together with a significant depletion of enzymatic and non-enzymatic antioxidants in the stratum corneum, epidermis and dermis

7. UV PROTECTION FACTOR (UPF) UV protection factor is the ratio of average effective UV radiation irradiance transmitted and calculated through air to the average effective UV radiation irradiance transmitted and calculated through fabric. GRADE UPF Good protection 15 - 24 Very good protection 25 - 39 Excellent protection 40 - 50+

8. SUN PROTECTION FACTOR (SPF) It is a measure of how much solar energy (UV radiation) is required to produce sunburn on protected skin (i.e., in the presence of sunscreen) relative to the amount of solar energy required to produce sunburn on unprotected skin. As SPF value increases, sunburn protection increases. PROTECTION LEVEL SPF VALUE Low 6, 10 Medium 15, 20, 25 High 30, 40 Very high 50+

9. SUNSCREEN Sunscreen (also known as sunblock or suntan lotion ) is a lotion, spray, gel or other topical product that absorbs or reflects the sun’s ultraviolet (UV) radiation and protects the skin. Sunscreens are classically divided into : Physical sunscreens : - These are inorganic and reflect, scatter or/and absorb UV radiation. - These are opaque formulations containing : - Titanium dioxide - Talc, kaolin - Zinc oxide - Ferric chloride - Ichthyol, red petrolatum

10. Chemical sunscreen : - These absorbs into the skin and then absorb UV rays, converts the rays into heat, and releases them from the body. - These formulations contain one or more - PABA, PABA esters - Benzophenones - Cinnamates - Salicylates - Digalloyl trioleate - Anthranilates

11. Ultraviolet (UV ) filters , are added to sunscreens to  absorb or block UV radiation from the sun . UV filters are regularly used in cosmetics for sun protection purposes. Chemical filters : Avobenzone , oxybenzone , octinoxate, Mineral filters : zinc oxide , titanium oxide. Emollients function as solubilizers of solid organic UV filters. Ex : Alkyl Benzoate , Dibutyl Adipate , Caprylic/Capric Triglyceride , Coco-caprylate , Isopropyl Myristate , Dicaprylyl Carbonate.

12. IDEAL CHARACTERISTICS OF SUNSCREEN It should be resistant to water and perspiration. It should allow full transmission of radiation in the range of 300 to 400 nm for tanning effect. It should ne non-volatile. It should have suitable solubility characteristics in suitable vehicle. It should be stable to heat, light and perspiration. It should be non-toxic, non-irritant and non-sensitizing. It should be capable of retaining its own scaling property for several hours. It should not stain on body cloth. It should be neutral.

13. REGULATORY ASPECTS Sunscreens are evaluated generally one of following method and fulfills labelling conditions as per countries guidelines: US-FDA Method: The FDA approval measures in-vitro UV transmittance through a sunscreen film using the critical wavelength method. Sunscreen products offering primarily UV-B protection would have a critical wavelength less than 320nm, whereas those providing both UV-B and UV-A protection would have critical wavelengths between 320 and 400nm. FDA requires that sunscree3n products have a critical wavelength of at least 370nm ( the mean value must be equal to or greater than 370nm) to be labelled as providing “broad spectrum” UV-A and UV-B protection.

14. INTERNATIONAL ORGANIZATION FOR STANDARDIZATION (ISO): It is an independent, non-governmental international organization in Geneva with a membership of 162 national standard bodies. Following are different methods of ISO for sunscreens: ISO 24443:2012 specifies an “in-vitro” procedure to characterize the UV-A protection of sunscreen products. Specifications are given to enable determination of the spectral absorbance characteristics of UV-A protection in a reproducible manner. In order to determine relevant UV-A protection parameters, the method has been created to provide a UV spectral absorbance curve from which a number of calculations and evaluations can be undertaken. This method relies on the use of in-vivo SPF results for scaling the UV absorbance curve. ISO 24442:2011 specifies an “in-vivo” method for assessment of the UV-A protection factor (UVAPF) of topical sunscreen products. It is applicable to cosmetics, drugs and other products intended to be topically applied to human skin, including any component able to absorb, reflect or scatter UV rays, ISO24442:2011 provides a basis for the evaluation of sunscreen products for the protection of human skin against UV-A radiation from solar or other light sources.

15. ISO 24444:2010 specifies a method for the in-vivo determination of the sun protection factor (SPF) of sunscreen products. The International Standards is applicable to products that contain any component able to absorb, reflect or scatter UV rays and which are intended to be placed in contact with human skin. ISO 24444:2010 provides a basis for the evaluation of sunscreen products for the protection of human skin against “erythema” induced by solar UV rays.

16. INDIA: Indian being Asian population comes under Type-IV skin pattern which burns minimally and tans easily. Freckles are rare but still use of sunscreen is necessary to avoid tan. Indian regulations date from the Indian Drug and Cosmetics Act (1940) as amended from time to time considers sunscreen as cosmetics. Bureau of Indian Standards (BIS), a participating member of the ISO, sets relevant cosmetic product standards. Key points are stability data is must and there is no maximum SPF rating for sunscreens. JAPAN: Japan Cosmetic Industry Association (JCIA) provides self regulated standards. JCIA is a signatory to the COLIPA International SPF test method and JCIA has adopted ISO standards as they are published. For SPF, ISO 24444 is accepted. In Japan, for UV-A, in-vivo testing is required and labelling is according to the ratings of Protection Grade of UV-0A (PA) i.e., PA+, PA++ and PA+++. Additionally, PA++++ was also added from 1 st January 2013.

17. REFERENCES https://innovareacademics.in/journals/index.php/ijap/article/download/27379/16156 https://www.slideshare.net/prashantlpingale/sunscreen-preparations . Handbook of cosmetic science and technology. https://www.slideshare.net/AkashNawkhare/sunscreen-244012908 . What Sunscreen Ingredients to Look for — and Which to Avoid (healthline.com)