Practical tools for boosting sunscreen efficacy Yun Shao, Pascal Delrieu, Ed Bartholomey and David Schlossman Kobo Products, Inc. Sunscreen Symposium 2015
High SPF Sunscreen Trend High SPF (50+) has become more desirable with increased consumer awareness of the risks of harmful UV exposure. Market share of SPF 50+ products has experienced global growth. Sunscreen boosters have become popular for efficacy enhancement and added skin benefits. High SPF Sunscreen Products
High SPF Sunscreens Ingredient Analysis Organic sunscreens Photostabilizer Anti-oxidants and bioactives Banana Boat Ultra Defense Clear Continuous SPF 110 UltraMist Sunscreen Spray Coppertone Sport Sunscreen Lotion SPF 75+ Diethylhexyl Syringylidenemalonate Diethylhexyl Syringylidenemalonate Diethylhexyl Syringylidenemalonate, Aloe Barbadensis Leaf Extract, Retinyl Palmitate, Ascorbic Acid, Tocopheryl Acetate Diethylhexyl Syringylidenemalonate,Tocopherol (Vitamin E), Retinyl Palmitate (Vitamin A), Sodium Ascorbyl Phosphate Neutrogena Sport Face Lotion SPF 70+ Diethylhexyl 2,6- Naphthalate Bisabolol, Artemia Extract, Saccharomyces/Zinc Ferment, Saccharomyces/Magnesium Ferment, Saccharomyces/Calcium Ferment, Saccharomyces/Sodium Ferment, BHT, Dipotassium Glycyrrhizate Neutrogena Pure & Free Baby Sunblock Lotion, SPF 60+ Butyloctyl Salicylate Ascorbic Acid (Vitamin C), Retinyl Palmitate, Tocopheryl Acetate, Bisobolol, Pantothenic Acid, Avena Sativa (Oat) Kernel Extract, Dipoassium Glycyrrhizate (Licorice Root)
High SPF Sunscreen Ingredient Analysis Inorganic sunscreens Photostabilizer Anti-oxidants and bioactives Replenix Ultra Sheer Physical Sunscreen Spray SPF 50 --- Ascorbic Acid, Ascorbyl Palmitate, Biotin, Camellia Sinensis (Green Tea) Polyphenols, Emblica Officinalis Fruit Extract, Retinyl Palmitate, Resveratrol, Tocopheryl Acetate, Ubiquinone skinceuticals Physical Fusion UV Defense SPF 50 Butyloctyl Salicylate DermaQuest SunArmor SPF 50 --- Dr Dennis Gross Sheer Mineral Sun Spray SPF 50+ --- Tocopherol, Artemia Extract Tocopheryl Acetate, Ectoin, Palmitoyl Oligopeptide, Palmitoyl Tetrapeptide-7, Vitis Vinifera (Grape) Fruit Cell Extract, Polygonum Aviculare Extract, Tocopherol, Ascorbic Acid, Ascorbyl Palmitate Ascorbic Acid, Ascorbyl Palmitate, Biotin, Camellia Sinesis Leaf Extract, Resveratrol, Tocopheryl Acetate, Ubiquinone is Clinical Eclipse SPF50+ Sunscreen --- Tocopherol, Tocopheryl Acetate AVEENO Natural Protection Lotion Sunscreen with Broad Spectrum SPF 50 --- Bisabolol, Dipotassium Glycyrrhizate, Avena Sativa(Oat) Kernel Extract
Transmittance Curves of Inorganic Sunscreens 100 %T 80 Sunscreen product Actives on label TiO 2 % ZnO% Est SPF based on active% Replenix NA 13.75 < 30 Dr. Dennis Gross NA 12 < 25 60 SkinCeutical 6 5 < 20 Eclipse 5.2 1.1 < 20 40 20 0 320 360 400 440 nm Antioxidants/bioactives do not affect the UV attenuation of inorganic UV filters No effect on critical wavelength T% curves match the patterns of those of TiO 2, ZnO or their combo But they do greatly boost SPF to SPF50+
Outline I. Test and analysis the boosting effect of Antioxidants and bioactive compounds Organic sunscreen photostabilizers Film formers / Light scattering particles II. High SPF/PFA formulation strategy
Antioxidant & bioactive compounds
Patents and Other Literature Claims that antioxidants can protect against free-radicals & cellular damage have become widely accepted by consumers Projected demand for antioxidant-fortified products is increasing by about 8.5%-10.0% annually (Cosmeceuticals, US Industry Study with Forecasts for 2012 & 2017, The Freedonia Group) 1. Antioxidants in sunscreens for Improved ROS protection KM Hanson, C&T, Vo. 126, No. Oct. 2011 0.5% vitamin E and 0.9% diethylhexyl syringylidene malonate (DESM) -- prevent ROS formation -- Effect levels off at high SPF (70) 2. T Meyer et al. US 20090189090 A1, Jul 30, 2009 Method to test the composition for ability to inhibit both UV induced lipid peroxidation on skin and ROS formation in the epidermis.
Patents and Other Literature JD Rigal, US 5618521 A, April 8, 1997 -Photoprotective/cosmetic compositions comprising antioxidants and filamentous bacterial extracts (i) at least one antioxidant and (ii) at least one extract of at least one nonphotosynthetic and nonfructifying filamentous bacteria. E Shim US 20080102045 A1, May 1, 2008 -Topical preparations containing antioxidant extracts of broccoli, green tea, and red tea for the protection of photocarcinogenesis H Murad, US 5,804,168, Sept 8, 1998 - pharmaceutical compositions and methods for protecting and treating sun damaged skin mixture of botanical extracts to boost SPF of TiO 2 Sunscreen up to ~ 10% Olga Dueva, US 8465729 B2, June 18, 2013 - Sunscreen compositions with SPF enhancer (carotenoid ) 16 Wt. % sunscreen agents and about 0.011% lutein SPF 29.65 was boosted to 31.5
Discoloration of TiO 2 by Antioxidants Primary size: 10 nm 15 nm 60 nm TiO 2 Composition: TiO 2 - coated with alumina and silicone 1.0 g Ascorbyl palmitate (as example) 0.01g Ester 6.5 g
Objective of Study Create an antioxidant cocktail with the purpose of meeting aesthetic requirements, low odor, light color, etc. substantially boosting SPF of sunscreen compositions compatible with inorganic UV filters Provide a practical guidance of use level and estimated boosting effect
Compatibility with Nano TiO 2 Ascorbyl Pamitate Aquarox 10-302057 Ascorbic Acid Fine Powder White Tea Liposomes Rosemary Oleoresin Green Tea Liposomes Green Tea Herbasol Extract FSG33 (Feruloyl Soy Glycerides) White Tea Herbasol Extract Covi-Ox T70C Vitamin A Palmitate (1.7 MIU/g) dl-alpha-tocopherol (USP) Combray Ethyl Ascorbic Acid Merlot Polyphenols IBR-TCLC in Jojoba Oil Magnesium Ascorbyl Palmitate IBR-AAC dl-alpha-tocopheryl Acetate Stay C 50 (Sodium Ascorbyl Argan Oil IBR-CLC TNP50T7 - CONTROL TNP50T7 50% Disp of 15 nm TiO 2 w/alumina+methicone coating 5% addition to TNP50T7 5 days at RT 0 10 20 30 40 Discoloration (DE)
Antioxidants Selected for SPF Boosting Two stable compounds are selected: > Argan oil: produced from the kernels of the Argan tree; Contains antioxidants such as tocopherols, phenols, carotenes. > Tocopheryl acetate: a very potent anti-oxidant A Booster Blend ATB was created with: Argan oil major component VE acetate minor component Bisabolol minor component, a natural anti-irritant, anti-inflammatory agent Stable with 15 nm TiO 2 for over 2 years (DE < 1.5)
Base W/O Formula for Testing Pt Percent 1 2 18.53 INCI Name C12-15 Alkyl Benzoate (And) Titanium Dioxide (And) Alumina (And) Polyhydroxystearic Acid (And) Methicone 10.00 Cyclopentasiloxane 10.00 C12-15 Alkyl Benzoate (+ Boosters to tested) 3.00 Caprylyl Methicone 3.00 Polyglyceryl-4 Isostearate (And) Cetyl PEG/PPG-10/1 Dimethicone (And) Hexyl Laurate 1.00 Trihydroxystearin 1.00 Glyceryl Stearate 1.00 Dimethicone 46.97 Water 1.00 Propylene Glycol (And) Diazolidinyl Urea (And) Methylparaben (And) Propylparaben 1.00 Sodium Chloride 1.00 PEG-150/Decyl Alcohol/SMDI Copolymer 0.50 Polysorbate 20 3 2.00 Silica TiO 2 : added as dispersion TiO 2 %: 7 QS : C12-15 alkyl Benzoate Control: Base formula with no booster. Same through this work UV Protection testing: Lab: SPF/CW: PFA: Panel: AMA Laboratory FDA method JCIA PPD method 3 persons Skin type II and III
Boosting Efficacy vs. Use Level 40 30 20 SPF 22.5 27.5 32.0 36.5 32.1 38.5 10 0 0 1 2 3 4 5 (Booster Blend ATB%) Boosting effect is significant (up to 60%) Boosting plateaus in the range of ~ 3 5%
Contribution of Components SPF 30 20 10 0 SPF Boost 22% 27% 17% Control ARGAN OIL BISABOLOL VE Acetate Each component is extracted from 3% of Booster blend ATB Both anti-oxidant and antiinflammatory agent boost SPF Contribution from each component is fairly balanced out at the ratio in Blend ATB
40 Cumulative Boosting Effect SPF SPF Boost 22% 27% 17% 62% 30 20 10 0 Control ARGAN OIL BISABOLOL VE Acetate 3% ATB Boosting effect of each components is largely cumulative in this formulation Component ratio ensures optimal synergy
Booster Blend ATB - Efficacy vs. TiO 2 % TiO 2 % 7 12 ATB 3.0 4.2 5 6.5 SPF 36.5 32.1 38.5 52.3 SPF/TiO 2 % 5.21 4.58 5.50 4.35 At high TiO 2 use level, boosting effect may be neutralized due to less additive impact on skin cells There is possibly a range for maximum boosting efficiency, which corresponds to the finding in Hanson s work
Boosting Inorganic Sunscreens F11A F11C % TiO 2 6.0 6.0 % ZnO 4.6 4.6 % ATB - 5.0 SPF 31.40 44.93 % Boost - 43.1% F12 F12A % TiO 2 4.8 4.8 % ZnO 3.4 3.4 % ATB - 3.6 PFA 7.49 10.09 % Boost - 34.7% Booster blend ATB boosts the SPF of combined inorganic sunscreens Booster blend ATB provides boosting in UVA as effective as in UVB
SPF Boost to Organic Sunscreens F13 F13V % Avobenzone 3.0 3.0 % Homosalate 15.0 15.0 % Octisalate 5.0 5.0 % Oxybenzone 3.0 3.0 % ATB - 5.0 SPF 40.9 54.8 % Boost - 34.0% TiO 2 (230 nm) ZnO (265nm) Ocinoxate F15A 3.60% 11.85% 7.50% F15B % ATB - 5.0 SPF 44.0 57.5 % Boost - 30.0% CW (nm) 373.7 373.8 SPF boosting effect is still significant. Boosting effect to high SPF (50+) formulas seems to be lower than that for low SPF (30+) formulas. No effect on critical wavelength was observed.
Organic Sunscreen Photostabilizers
Organic Sunscreen Photostabilizers Butyloctyl salicylate (BOS) > Stabilize Avobenzone > Boost SPF effectively > Helpful for SPF 30+ formulas > l max : 306 nm (UVB) Ethylhexyl Methoxycrylene-(EHMC) > Stabilize Avobenzone > Boosts PFA very effectively > Helpful for PA+++ or higher > l max : 340 nm (UVA)
Boosting Effect of Butyloctyl Salicylate 30 20 SPF 22.5 40% 31.5 10 0 Control Control + BOS (5%) Control: base formula with 7% TiO 2 BOS was added in the form of TiO 2 Dispersion SPF unit/bos%: estimate to be 1.6
PFA Boosting effect of Ethylhexyl Methoxycrylene Formula F16 F17 F16H F17A ZnO Primary size (nm) ~25 ~260 ZnO% 15% 15% 15% 15% EMHC (as part of ZnO Disp) PFA boosting is significant -- 5.85 --- 2.86 PFA 7.5 11.7 5.52 10.8 % boost -- 56 --- 96 The phtotostabilizer shows a great synergy with ZnO, and expectedly TiO 2 due to their scattering nature Effective SPF boosting is also expected because of enhanced PFA
Film Formers & Light Scattering Particles
Literature - Film Former JR Strobridge, US 4917883, April 17, 1990, - O/W emulsion sunscreen composition - 0.5 and about 20 weight percent of a copolymer of ethylene and vinyl acetate together with a second polymeric film forming agent which increases the substantivity of the film forming composition TA Meyer, WO 2010129215 A2, Nov.11, 2010 -Enhanced efficiency of sunscreen compositions -Compositions comprising UV blocking agents, a film forming polymer containing acid groups and a neutralizing agent N Herman, WO 2013036878 A1, Mar 14, 2013 -Polyamide compositions for personal care Disclose a hydrophobic polyamide made from a dimerized fatty acid and polyamine SPF increase: 160% in an SPF 30 & > 250% in an SPF 50+ formulation
Film Formers Tested CH 3 CH 2 C CH 2 CH x COOCH 3 COOC 2 H 5 y Acrylates Copolymer (ACP) - High MW, - Water dispersible latex - Film forming - irreversible Hydrogenated Polycyclopentadiene (HPCD) - Low MW - Oil soluble - Adhesion promoter
SPF Boosting Effect of Film Former 40 30 SPF SPF Boost 22% 53% 20 10 0 Control ACP (2% active) HPCD (2%) Both water dispersible and oil soluble film former helps boost SPF The use level needs to be controlled to maintain good skin feel
Literature Light Scattering Agents H Xing US 20120107253 A1, May 3, 2012 -sunscreen formulations using natural oceanic clay (aka marine glacial clay) Sunscreen formulations use the Natural Oceanic Clay when combined with sunscreen actives such as zinc oxide, can provide significant enhancement in absorbance of UVA, UVB, and UVC ( clay size: 80 200 mesh; Boosting by in-vitro testing: 50 236% ) Sunsphere PGL from Dow, -- Technical Brochure Sept. 2003 Hollow styrene/acrylic copolymer spheres (~250 nm) for enhancing UV protection 5% Sunsphere (~1.25% active) boosts SPF up to 70%
Formulation Strategy for High UV Protection Sunscreen actives Antioxidants Anti-inflammatory Zone Film formers Light scattering agents Organic sunscreen stabilizer
High UV Protection Testing Formula (O/W) Part Percent INCI Name 1 45.70 Water 2 5.00 Niacinamide 1.00 Polysorbate 20 0.20 Methylparaben 3 4.00 Glycerin 0.20 Xanthan Gum 4 9.80 Zinc Oxide (And) Ethylhexyl Methoxycrylene (And) C12-15 Alkyl Benzoate (And) Polyhydroxystearic Acid (And) Hydrogen Dimethicone 9.50 C12-15 Alkyl Benzoate 8.65 Butyloctyl Salicylate (And) Titanium Dioxide (And) Alumina (And) Silica (And) Stearic Acid (And) Polyhydroxystearic Acid 5.00 Argania Spinosa Kernel Oil (And) Tocopheryl Acetate (And) Bisabolol 2.45 PEG-100 Stearate 1.00 Glyceryl Stearate 0.40 Shea Butter 0.10 Propylparaben 5 3.00 Silica 1.00 Polyacrylamide (And) C13-14 Isoparaffin (And) Laureth-7 6 3.00 Acrylates Copolymer (And) Water
Summary of Formula and Testing Scores Ingredient INCI % Sunscreen actives TiO 2 (40 nm) 3.54 ZnO (265 nm) 7.15 Antioxidant/ Anti-inflammatory Booster blend ATB 5.00 Ethylhexyl Methoxycrylene 1.37 UV absorber/stabilizer Butyloctyl salicyalte 4.48 Film former Acrylates copolymer 1.5 Index Value Estimated value without boosters SPF 66 15-20 PFA 21 5 CW (nm) 380 380
Summary Antioxidants and bioactive compounds have great ability to boost the UV protection of sunscreen formulas against both UVA and UVB. The boost effect can be cumulative. However, their chemical compatibility with inorganic UV filters needs to be tested. Certain organic sunscreen photostabilizers can also boost effectively SPF or PFA depending on the absorption peak. They have good synergy with inorganic UV filters. Both water dispersible and oil soluble film formers were tested to be effective. SPF/PFA boosters of different mechanisms, when used in proper combination, can boost protection multifold. This also helps to reduce the use of actives and improve the skin feel and asethetics of sunscreen formulations.
Acknowledgment Fred Ortiz Kobo Application Lab