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Effect of the combination of organic and inorganic filters on the Sun Protection Factor (SPF) determined by in vitro method


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This paper describes the effect on Sun Protection Factor (SPF) of the combination of inorganic and organic filters in sunscreen products as determined by an in vitro method. O/W emulsions containing inorganic filters, such as titanium dioxide and zinc oxide, combined with 18 EU-authorized UV-B organic filters were tested. SPF measurements were carried out using a spectrophotometer equipped with an integrating sphere. This study observed a synergic effect when titanium dioxide was combined with either anisotriazine or octyldimethylPABA. The combination of zinc oxide with 11 UV-B organic filters also exhibited a similar synergy; however, the measured SPF was systematically lower than the protection factor achieved with titanium dioxide.
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International Journal of Pharmaceutics 340 (2007) 1–5
Rapid communication
Effect of the combination of organic and inorganic filters on the Sun
Protection Factor (SPF) determined by in vitro method
S. El-Boury, C. Couteau, L. Boulande, E. Paparis, L.J.M. Coiffard
Universit´e de Nantes, Nantes Atlantique Universit´es, LPiC, SMAB, EA2160, Faculty of Pharmacy, 1 rue G. Veil - BP 53508, Nantes F-44000, France
Received 22 March 2007; received in revised form 10 May 2007; accepted 12 May 2007
Available online 26 May 2007
This paper describes the effect on Sun Protection Factor (SPF) of the combination of inorganic and organic filters in sunscreen products
as determined by an in vitro method. O/W emulsions containing inorganic filters, such as titanium dioxide and zinc oxide, combined with 18
EU-authorized UV-B organic filters were tested. SPF measurements were carried out using a spectrophotometer equipped with an integrating
This study observed a synergic effect when titanium dioxide was combined with either anisotriazine or octyldimethylPABA. The combination of
zinc oxide with 11 UV-B organic filters also exhibited a similar synergy; however, the measured SPF was systematically lower than the protection
factor achieved with titanium dioxide.
© 2007 Elsevier B.V. All rights reserved.
Keywords: Inorganic; Organic; Filter; Combination; Synergy; SPF in vitro
1. Introduction
UV constitutes about 10% of the total solar radiation. There
are two categories of UV radiation: UV-A and UV-B. UV-A
(320–400 nm) has lower energy than UV-B, however, it pene-
trates more deeply and does not burn skin as easily. The 95% of
UV radiation is UV-A. UV-B (290–320 nm) radiation has higher
energy and penetrates only the outer skin layers, but induces skin
burns more easily (Hoffman et al., 2000). UV radiation has both
positive and negative effects. Positive effects of UV radiation
include warmth, light, photosynthesis in plants and vitamin D
synthesis in the skin (UV light converts a cholesterol derivative
into previtamin D3) (Holick et al., 1980). Overexposure to UV
radiation is the primary environmental risk factor in the devel-
opment of UV-related adverse health conditions, which include
diseases of the eye (Sliney, 2001), immune suppression (Norval,
2006) and skin cancers. Exposure to UV radiation appears to be
the most important environmental factor in the development of
skin cancer (Hussein, 2005). The increase in skin cancer has
resulted from an increased outdoor leisure time and a decrease
Corresponding author. Tel.: +33 2 40 41 28 73; fax: +33 2 40 41 29 87.
E-mail address: (L.J.M. Coiffard).
in the amount of protective clothing worn outdoors (Vanquerp
et al., 1999; Marks, 1999; Couteau et al., 2001; Morison, 2003).
Sun Protection Factor (SPF) is the universal indicator for
describing the efficiency of sunscreen products. It is the ratio
of the least amount of ultraviolet energy required to produce a
minimal erythema on sunscreen protected skin to the amount of
energy required to produce the same erythema on unprotected
skin (FDA, 1978). In this way, SPF indicates the ability of a sun-
screen product to reduce UV-induced erythema. It is measured
by both in vivo (Colipa method) and in vitro methods (Groves et
al., 1979). It is recommended to use sunscreen products with an
SPF of 15 or higher. This paper describes the study of the effect
of the combination of organic and inorganic UV filter substances
on the SPF of topically applied sunscreen formulations, using
an in vitro method.
2. Materials and methods
2.1. Materials
Tables 1 and 2 present the filters (organic and inorganic) and
their characteristics. Dimethicone (Abil®WE 09) was obtained
from Goldschmidt (Montigny-le-Bretonneux, France). Cetiol®
HE, stearic acid, glycerin, parabens and triethanolamin (TEA)
0378-5173/$ – see front matter © 2007 Elsevier B.V. All rights reserved.
2S. El-Boury et al. / International Journal of Pharmaceutics 340 (2007) 1–5
Table 1
Characteristics of the organic sunscreens investigated
INCI name Suppliers λmax (nm) Solubility Maximum concentration
authorized (%)
PABA Merck, Fontenay sous Bois, France 290.0 Hydrosoluble 5
Homosalate Merck, Fontenay sous Bois, France 306.0 Liposoluble 10
Oxybenzone BASF, Levallois-Perret, France 287.5 Liposoluble 10
Phenylbenzimidazole sulfonic acid Merck, Fontenay sous Bois, France 305.5 Hydrosoluble after
neutralisation with NaOH
Octocrylene BASF, Levallois-Perret, France 304.0 Liposoluble 10
Octylmethoxycinnamate BASF, Levallois-Perret, France 310.0 Liposoluble 10
PEG-25 PABA BASF, Levallois-Perret, France 307.0 Hydrosoluble 10
Isoamyl p-methoxycinnamate Symrise, Neuilly sur Seine, Paris 310.0 Liposoluble 10
Octyltriazone BASF, Levallois-Perret, France 314.5 Liposoluble 5
Diethylhexylbutamidotriazone Cr´
eations couleur, Dreux, France 310.5 Liposoluble 10
4-Methylbenzylidene camphor Merck, Fontenay sous Bois, France 301.0 Liposoluble 4
3-Benzylidene camphor Unipex, Rueil Malmaison, France 291.05 Liposoluble 2
Octylsalicylate Alzo, Helsinki, Finland 306.0 Liposoluble 5
OctyldimethylPABA Merck, Fontenay sous Bois, France 312.0 Liposoluble 8
Benzophenone-5 BASF, Levallois-Perret, France 287.5 Hydrosoluble 5
Methylene bis-benzotriazolyl
Ciba, Grenzach-Wyhlen, Germany 305.5 Hydrosoluble 10
Anisotriazine Ciba, Grenzach-Wyhlen, Germany 310.0 Liposoluble 10
Polysilicone 15 Roche, Fontenay sous Bois, France 312.5 Liposoluble 10
Table 2
Characteristics of the inorganic sunscreens investigated
INCI Name (Trade name) Suppliers Solubility Maximum concentration
authorized (%)
Titanium dioxide, hydrated silica, aluminium hydroxide,
dimethicone/methicone copolymer (T-Lite SFS)
BASF, Levallois-Perret, France Liposoluble 25
Zinc oxide, diphenyl capryl methicone (Z-Cote Max) BASF, Levallois-Perret, France Liposoluble
were purchased from Cooper (Melun, France). Xanthan gum
(Keltrol®BT) was obtained from Kelco (Lille Skensved, Den-
mark). Polymethylmethacrylate (PMMA) plates were purchased
from Helioscience (Creil, France). Powder-free latex finger cots
were obtained from Cooper (Melun, France).
2.2. Preparation of sunscreen creams
Each O/W emulsion was prepared in the laboratory by com-
bining organic and inorganic filters, in the highest EU-authorized
concentration, to a basic formula (Table 3) were manufactured by
the authors. Hydrophilic-phase and oil-phase were heated sepa-
rately to between 78 and 82 C, until the ingredients of each part
were solubilized. Next, the oily preparation was added slowly to
the hydrophilic preparation with constant stirring (Yellow line
OST basic mixer, IKA, Staufen, Germany). It was necessary to
continue stirring until the resulting emulsion was cooled to room
temperature (20 C). In addition, sunscreen agents were incor-
porated at various concentrations into this emulsion. A filterless
cream was used as a blank (Couteau et al., in press-a,b).
2.3. Study of effectiveness
Thirty milligrams of precisely weighed product were spread
across the entire surface (25 cm2) of a polymethylmethacry-
late (PMMA) plates using a cot-coated finger. Plates have both
a smooth and a rough surface. The roughness was measured
between 5 and 10. After spreading, 15 mg of the product
remained on the finger cot. The SPF of the creams was then
measured in vitro. Three plates were prepared for each product
to be tested and nine measurements were performed on each
plate. Transmission measurements between 290 and 400 nm
Table 3
Composition of the emulsion
Ingredients Percent by weight
Abil®WE 09 (polyglyceryl-4 isostearate;
cetyl PEG/PPG-10/1 dimethicone; hexyl
Paraffin oil 12
Cetiol®HE (PEG-7 glyceryl cocoate) 5
Butylhydroxytoluene 0.01
Stearic acid 5
Eumulgin®B1 (Ceteareth-12) 1.5
Eumulgin®B2 (Ceteareth-20) 1.5
Glycerine 4
Sodium propylparaben 0.05
Sodium methylparaben 0.1
Keltrol®BT (xanthan gum) 0.9
TEA 0.3
Distilled water qsp 100.0
S. El-Boury et al. / International Journal of Pharmaceutics 340 (2007) 1–5 3
Table 4
Combination of UV-B filters and titanium dioxide
Filter (INCI name) SPF (filter) (mean ±S.D.) SPF (filter + titanium
dioxide combination)
(mean ±S.D.)
Increase or decrease of SPF
compared to predicted SPF
(SPF units)
PABA 5.48 ±0.62 41.04 ±6.05 –
Homosalate 4.25 ±0.96 38.09 ±3.27 4
Oxybenzone 5.10 ±0.57 39.07 ±4.11 4
Phenylbenzimidazole sulfonic
13.39 ±1.60 49.37 ±11.07 –
Octocrylene 9.40 ±1.42 43.42 ±3.79 –
Octylmethoxycinnamate 12.09 ±1.20 53.12 ±4.69 –
PEG-25 PABA 4.09 ±0.56 35.87 ±3.08 6
Isoamyl p-methoxycinnamate 13.49 ±1.90 52.84 ±5.85 –
Octyltriazone 12.54 ±2.15 36.57 ±3.67 14
Diethylhexylbutamidotriazone 10.73 ±1.44 47.27 ±3.89 –
4-Methylbenzylidene camphor 6.44 ±0.88 43.38 ±2.99 –
3-Benzylidene camphor 2.84 ±0.47 33.47 ±4.03 7
Octylsalicylate 2.89 ±0.37 38.81 ±4.13
OctyldimethylPABA 8.98 ±0.81 53.55 ±4.07 +7
Benzophenone-5 5.59 ±0.88 35.77 ±3.61 7
6.68 ±1.80 19.50 ±4.03 25
Anisotriazine 29.63 ±4.19 73.06 ±4.96 +6
Polysilicone 15 4.25 ±0.95 38.77 ±4.32 –
were carried out using a spectrophotometer equipped with an
integrating sphere (UV Transmittance Analyzer UV1000S, Lab-
sphere, North Sutton, US). The SPF were carried out according
to the following equation:
SPF =400
where Eλis CIE erythemal spectral effectiveness, Sλis solar
spectral irradiance and Tλis spectral transmittance of the
sample (Ferrero et al., 2003; Villalobos-Hernandez and M¨
Goymann, 2007).
3. Results and discussion
The SPF of the cream containing 25% titanium dioxide or
25% zinc oxide was, respectively, 37.65 ±3.90 and 7.14 ±1.22.
Table 5
Combination of UV-B filters and zinc oxide
Filter (INCI name) SPF (filter) (mean ±S.D.) SPF (filter +zinc oxide
(mean ±S.D.)
Increase or decrease of SPF
compared to predicted SPF
(SPF units)
PABA 5.48 ±0.62 10.94 ±1.22 –
Homosalate 4.25 ±0.96 11.94 ±2.25 –
Oxybenzone 5.10 ±0.57 13.42 ±1.61 –
Phenylbenzimidazole sulfonic
13.39 ±1.60 24.76 ±3.82 +4
Octocrylene 9.40 ±1.42 25.74 ±2.57 +9
Octylmethoxycinnamate 12.09 ±1.20 26.63 ±2.98 +7
PEG-25 PABA 4.09 ±0.56 15.06 ±3.18 +4
Isoamyl p-methoxycinnamate 13.49 ±1.90 29.07 ±3.56 +8
Octyltriazone 12.54 ±2.15 25.88 ±2.94 +6
Diethylhexylbutamidotriazone 10.73 ±1.44 49.28 ±4.37 +31
4-Methylbenzylidene camphor 6.44 ±0.88 15.16 ±2.06 –
3-Benzylidene camphor 2.84 ±0.47 12.72 ±1.77 +3
Octylsalicylate 2.89 ±0.37 9.08 ±1.40 –
OctyldimethylPABA 8.98 ±0.81 28.51 ±2.94 +12
Benzophenone-5 5.59 ±0.88 15.28 ±1.42 +3
Methylene bis-benzotriazolyltetra
methyl butylphenol
6.68 ±1.80 12.92 ±1.90 –
Anisotriazine 29.63 ±4.19 36.89 ±3.29 –
Polysilicone 15 4.25 ±0.95 15.55 ±1.37 +4
4S. El-Boury et al. / International Journal of Pharmaceutics 340 (2007) 1–5
Fig. 1. Decrease of effectiveness (%) for the combination between titanium
dioxide and methylene bis-benzotriazolyl tetramethylbutylphenol (MBBTP),
octyltriazone (OT), benzophenone-5 (BZ-5), 3-benzylidene camphor (3-BC),
PEG-25 PABA, benzophenone-3 (BZ-3) and homosalate (HMS).
We noted a clear superiority of TiO2over ZnO in terms of effec-
tiveness. A previous study established that SPF is a function
of filter concentration (Couteau et al., in press-a,b). There-
fore, by knowing the equation SPF = f(c) for each filter and
each separately added screen, it will be possible to predict
the SPF of sun creams combining both filter and screens.
We expect manufacturers to question the relevance of all of
these combinations, a query that will be answered by this
The effect of the combinations was evaluated statistically
by a Student’s t-test (N= 27; p< 0.05) (Tables 4 and 5). A
combination was considered relevant if the SPF of the cream
combining filter and screen was higher or equal to the SPF
obtained separately, filter only or screen only. On the other
hand, we considered a combination to be irrelevant if the SPF
of the combination remains inferior to the expected result. In
9 out of 18 trials, the creams formulated with TiO2revealed
a purely additive effect. Seven creams turned out to be less
promising than predicted (with a loss of SPF compared to
predicted results between 4 and 25) (Fig. 1). We found two
synergistic combinations worth noting: the cream formulated
with TiO2and anisotriazine resulted in a SPF value of about
70 (an increase of 6 SPF units). The second interesting com-
bination was obtained with octyldimethylPABA (an SPF about
55). The increase was about 7 SPF units. So it is possible to
predict the SPF of all the combinations between the various
In a large majority of the cases (11 out of 18), a combina-
tion with zinc oxide was more promising because it generated
more synergy (Fig. 2). In terms of an increase in SPF protection,
two combinations are particularly worth mentioning: the com-
bination with diethylhexylbutamidotriazone (an increase of 31
SPF units) and the combination with octyldimethylPABA (an
increase of 12 SPF units).
The formulated creams made with zinc oxide turned out
to be more reliable than those made with titanium dioxide in
the sense that there was no unexpected loss of SPF compared
with the predicted results. It will be necessary, however, to
Fig. 2. Increase of effectiveness (%) for the combination between zinc oxide
and diethylhexylbutamidotriazone (DHBT), octyldimethylPABA (OD-PABA),
octocrylene (OCT), isoamyl p-methoxycinnamate (IMC), octylmethoxycin-
namate (OMC), polysilicone-15 (P-15), PEG-25 PABA, octyltriazone (OT),
3-benzylidene camphor (3-BC), phenylbenzimidazole sulfonic acid (PBSA) and
benzophenone-5 (BZ-5).
further investigate the use of titanium dioxide because high
SPF (70 for example) products can be created with it; these
high values cannot be attained with zinc oxide (maximum
SPF of 49). By referencing Tables 4 and 5 of this paper as
well as the linear curves (SPF = f(c)) established in an ear-
lier study (Couteau et al., in press-a,b), it is possible to select
filter–screen combinations in function of a desired protection
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... 95% of UV radiation is related to UVA. UVB radiation has stronger energy, only penetrates to the outer layer of skin and makes it easy to burn [3,4]. UVA solar irradiance is moderately constant and the influence of sun angle or meteorological conditions on UVA is less than UVB [5]. ...
... After choosing the best formulation for base cream, a set of 51 experiments of sunscreens were made in the laboratory by adding specific concentrations of organic and inorganic UV filters (consist of BZ4, OS, OMC, AVO, nanocomposites of titanium dioxide and zinc oxide) into the base cream. Then it was stirred vigorously for one minute with agitator to acquire homogeneous emulsion [3,8]. ...
... ZnO and AVO percentages have positive effects on UVA protection (UVA/UVB, UVA1/UV and SUI) as the previous studies showed [3,11]. Figs. ...
Optimization of skin care emulsions from the viewpoint of surfactants and ultraviolet filters formulation has been investigated using the experimental design. In this study, due to the variety of factors affecting the final product, the continuous process has been executed in two studies (optimization of basecream and sunscreen). For the first study, six variables such as surfactants nature (three mixture variables), the percentages of surfactant, solvent and temperature have been investigated and stability and viscosity have been measured as responses. Using the exchange algorithm based on D-optimality criteria, a multiplied model has been supposed and a series of 45 experiments has been selected. In the second study, by Box-Behnken design a set of 51 experiments of sunscreens from the photoprotective efficacy and photostability viewpoint have been formulated and evaluated. These sunscreens contain four photo-protective organic filters such as benzophenone-4, octyl salicylate, octyl methoxy cinnamate and avobenzone and a new nanocomposite in which nanoparticles of TiO2 are dispersed onto micrometric ZnO particles by dry nanodispersion methodology at different percentages. The method was based on UV spectroscopic indices such as SPF, UVA/UVB ratio, UVA1/UV ratio, critical wavelength (CW), spectral uniformity index (SUI) and area under curve (Auc). Finally, these studies have been presented the optimal formulation for skin care emulsions to improve the sunscreen UVA and UVB protection.
... In the same way, we determined UPF-UVA according to the following equation: The ultraviolet protection factor (UPF) is the indicator used to rate the sun-protection qualities of garments. [8][9][10] The results for surgical masks are presented in Table 2 It is therefore safe to say that there is no need to apply sunscreen to your face before putting on a mask when you are exposed to the sun. ...
... These masks provide protection over a very wide spectrum, the critical wavelength reaching values close to 390 nm, exceeding the protection currently afforded by available topical products and filters. The protection provided by this type of mask is similar to that obtained by wearing certain cotton Tshirts.[8][9][10][11][12][13] Homemade cloth masks earned UVB protection scores ofbetween 400 and 500 (Figure 1). ...
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Background: It has become a general practice worldwide to wear a face mask serving as a barrier against the transmission of pathogens. Methods: This has prompted us to investigate whether masks could also protect our skin from UV radiation. We have studied 8 masks, 4 surgical and 4 'homemade' using an in vitro method. Findings: The study demonstrated that they all offered protection against both UVB and UVA radiation. As with clothing, fabric masks offer the highest level of protection against UV radiation. This article is protected by copyright. All rights reserved.
... Facing the limitations of natural UV actives, there is an urgent need of defining strategies for the preparation of sunscreen products with higher UVA/UVB ratio and excellent antioxidant activity against UVA damage, together with an adequate topical biodistribution kinetics. One of the most well-studied strategies is the development of nanotechnological formulations [17] of combining plant-derived actives with significant UVA protection with synthetic UV filters [101,102]. ...
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... The UV blocking from most natural oils is insufficient to obtain significant UV protection [7]. The strategies for preparations of sunscreen products with high SPF are nanotechnology formulations [8] and UV filter combinations [9], [10]. In this study, soybean oil was used as a natural UV filter, avobenzone and OMC as synthetic UV filters. ...
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BACKGROUND: Soybean oil contains vitamin E and acts as a natural sunscreen which can absorb Ultra Violet (UV) B light and has antioxidant properties to reduce the photooxidative damage that results from UV-induced Reactive Oxygen Species production. The UV blocking from most natural oils is insufficient to obtain a high UV protection. The strategies for preparations of sunscreen products with high SPF can be done by nanoemulsion formulation and Ultra Violet filter combinations of Soybean Oil, Avobenzone and Octyl methoxycinnamate. AIM: The purpose of this study was to prepare and in vitro efficacy evaluation of sunscreen nanoemulsion containing Soybean oil, Avobenzone and Octyl methoxycinnamate. METHODS: The sunscreen nanoemulsions were prepared by the high energy emulsification method. The formulation uses a combination of 3% Avobenzone, 7.5% Octyl methoxycinnamate, with different ratio of Soybean oil and Liquid Paraffin. The nanoemulsion was evaluated for droplet sizes by using particle size analyzer, physical stability in room temperature (25 ± 2°C during experiment for 12 weeks of storage, physical stability (cycling test), phase separation by centrifugation at 3750 rpm for 5 hours, pH, viscosity, and Sun Protection Factor (SPF) value by UV spectrophotometric. The SPF value of sunscreen nanoemulsion was compared to sunscreen nanoemulsion without Soybean Oil and sunscreen emulsion. Particle morphology observation of nanoemulsion by using Transmission Electron Microscope. RESULTS: The sunscreen nanoemulsion formulation containing a combination of 3% Avobenzone, 7.5% Octyl methoxycinnamate with a ratio of 2.73% Soybean Oil and 0.27% Paraffin Oil resulted in the smallest average droplet size of 68.47 nm. The sunscreen nanoemulsion without Soybean Oil had an average droplet size of 384.07 nm. The globules size was increased during the experiment for 12 weeks of storage at room temperature, but there was no phase separation after centrifugation. The formulation of sunscreen emulsion, phase separation was formed after centrifugation. The nanoemulsion had a pH value of 7.23 ± 0.06 and a viscosity value of 133.33 ± 7.22 cP. The sunscreen nanoemulsion containing a combination of 3% Avobenzone, 7.5% Octyl methoxycinnamate 2.73%, Soybean Oil, 2.73% and 0.27% Liquid Paraffin had SPF value (21.57 ± 1.21) higher than sunscreen nanoemulsion without Soybean Oil (16.52 ± 0.98) and sunscreen emulsion (15.10 ± 0.22). The TEM analysis of globules morphology showed that the sunscreen nanoemulsion formed a spherical globule. CONCLUSION: The sunscreen nanoemulsion containing a combination of 3% Avobenzone, 7.5% Octyl Methoxycinnamate, 2.73% Soybean Oil and 0.27% Liquid Paraffin showed synergistic sunscreen efficacy on SPF. This sunscreen nanoemulsion is more stable than sunscreen emulsion formulation during the experiment for 12 weeks at room temperature.
... Penelitian yang dilakukan (El-Boury et al., 2007) tentang perhitungan nilai SPF secara in vitro kombinasi berbagai senyawa tabir surya kimia dan tabir surya fisik pada konsentrasi tertinggi masing-masing senyawa tabir surya yang diperbolehkan oleh regulasi, salah satunya kombinasi oksibenzon dengan konsentrasi 10% dan titanium dioksida 25% menghasilkan nilai SPF sebesar 39,07 ± 4,11. Upaya peningkatan nilai SPF sediaan tabir surya dapat ditingkatkan dengan meningkatkan konsentrasi tabir surya fisik ataupun menambahkan jenis tabir surya kimia lainnya sehingga dapat dihasilkan sediaan tabir surya dengan nilai SPF 15 atau lebih. ...
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Efek buruk dari sinar matahari dapat dikurangi dengan penggunaan tabir surya. Optimasi emulgator trietanolamin (TEA) stearat dan setil alkohol pada krim tabir surya kombinasi oksibenzon dan titanium dioksida diharapkan menghasilkan formula optimum krim dengan stabilitas fisik yang baik. Tujuan penelitian ini yaitu mengetahui proporsi TEA stearat dan setil alkohol formula optimum dan nilai SPF krim o/w kombinasi oksibenzon dan titanium dioksida. Penetapan formula optimum dilakukan pada data uji sifat fisik krim menggunakan metode Simplex Lattice Design design software Design Expert version 9.0.4. Uji one sample t-test dilakukan untuk mengetahui perbedaan nilai antara formula optimum yang dihasilkan software Design Expert version 9.0.4 dengan hasil percobaan. Perbandingan sifat fisik formula optimum krim o/w kombinasi oksibenzon dan titanium oksida selama penyimpanan 4 minggu dianalisis menggunakan uji ANOVA. Pengujian nilai SPF secara in vivo dilakukan pada kelinci betina galur New Zealand White terinduksi senyawa 8-metoksiprosalen. Hasil penelitian menunjukkan proporsi TEA stearat dan setil alkohol yang menghasilkan formula optimum krim o/w kombinasi oksibenzon dan titanium dioksida adalah 8.93% dan 2.07%. Sifat fisik viskositas dan daya lekat tidak berbeda signifikan, sedangkan daya sebar berbeda signifikan selama penyimpanan 4 minggu. Pengujian aktivitas tabir surya secara in vivo krim o/w kombinasi oksibenzon dan titanium dioksida menghasilkan nilai SPF 12.
... Twelve commercial UV-filters spanning the 1 to 25 SPF range (Table S3) were used to develop the protocol. Experimental SPF values were compared with published data which were considered as reference values in this work [6][7][8] (Figure S1). For each compound, all indexes were determined from equations described above. ...
... The in vitro SPF values corresponding to the positive controls obtained in this assay are very close to those found in the literature in which FPS values of 5.48±0.62 and 12.09±1.20 are reported to 2-ethylhexyl 4-(dimethylamino)benzoate and 2-ethylhexyl 4-methoxycinnamate, respectively [26]. ...
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Objective: The aim of this research was to evaluate the photoprotective effect of Oreocallis grandiflora hydroalcoholic extract (OGHE) againstultraviolet (UV)B-induced cell death model on a strain of Escherichia coli (ATCC 25922) and to determine the sun protection factor (SPF) using theequation proposed by Mansur.Methods: OGHE was obtained from leaves of O. grandiflora, following a standardized methodology. In short, O. grandiflora leaves were extracted withethanol 70% v/v and defatted with n-hexane, hydroalcoholic fraction was concentrated under controlled conditions through rotary evaporator, andfinally, the residue was freeze drying to obtain OGHE. The photoprotective effect was carried out using in vitro UVB-induced cell death model on astrain of E. coli (ATCC 25922), like a first approach to study its potential application on cosmetics.Results and Conclusions: From results, O. grandiflora is an important resource to produce new cosmetic products. However, the safety of OGHE isnecessary to a rational development in that sense. OGHE shows advantages in relation to conventional active compounds of commercial sunscreens usedin this research (2-ethylhexyl 4-methoxycinnamate and 2-ethylhexyl 4-(dimethylamino)benzoate) at the concentration of 2 mg/mL, on survivor time(with OGHE until 120 min), range of inactivation of E. coli caused by UVB (OGHE K value minor against to positive controls), and high SPF (13.56±0.21).
The photocatalytic activity of ultraviolet (UV) filters, generating reactive oxygen species (ROS), must be minimized in skincare products to avoid adverse biological and chemical effects. Unfortunately, the screening effect of UV filters is intrinsically correlated with their photocatalytic activity in the presence of oxygen and water. Polymeric encapsulation has been widely employed to inhibit photochemical ROS generation; however, it can cause serious microplastic issues because UV filters act as photocatalysts under sunlight irradiation. Here we present plastic-free silica-titania-tannin (SiO2-TiO2-TA) heterojunction hybrids to increase UV-to-blue light blocking effects while suppressing UV-induced ROS generation by altering their photochemical routes. Mesoporous SiO2-TiO2 particles were prepared through the in situ synthesis of TiO2 nanocrystals within SiO2 particles, followed by the spontaneous deposition of TA via Ti-pyrogallol and Ti-catechol coordination. Ligand-to-metal charge transfer (LMCT) from TA to the conduction band of TiO2, demonstrated by theoretical calculations, extends the absorption spectrum of TiO2 over the blue wavelength regime, increasing a specific sun protection factor ∼ 1.8 times. The TA layer efficiently suppressed the UV-induced ROS generation: the SiO2-TiO2-TA produced only < 1 % hydroxyl radical ions compared to pristine TiO2 under simulated solar irradiation. Accordingly, the UV and blue light-induced cytotoxicity of fibroblasts was significantly alleviated by the ROS stabilization effect of TA complexed with TiO2, while pristine TiO2 exacerbated the cytotoxic effect via ROS generation in the cytoplasm. This work demonstrates that polyphenol coatings are a promising method to suppress the ROS generation by inorganic UV filters while increasing their screening effects through LMCT.
Ultraviolet (UV) filter nanocapsules were prepared by encapsulating organic UV filter octyl dimethyl para-aminobenzoic acid (OD-PABA) with miniemulsion polymerization using an amphiphilic random copolymer poly(styrene-co-methacrylic acid) (P(St-co-MAA)) as an emulsifier, methyl methacrylate (MMA) as the monomer and ethylene glycol dimethacrylate (EGDMA) as the crosslinker. TEM showed that the nanocapsules had irregularly spherical shape with an average diameter of 320 nm, and OD-PABA crystalline grains were encapsulated. The molar ratio of St to MAA in P(St-co-MAA) and the polymer emulsifier concentration, as well as the molar ratio of MMA to EGDMA in polymer coating significantly influenced the encapsulation efficiency and the leakage rate. At the optimum conditions, the encapsulation efficiency of OD-PABA reached to 33%. OD-PABA leakage in isopropyl myristate (IPM) could be ignored since the leakage rate maintained 1.3% during continuous stirring for 24 h. UV reflectance spectra showed that the UV filter nanocapsules had broad-spectrum UV blocking owing to the absorbance of OD-PABA combined with the scattering and reflection of the nanocapsules at submicron level. The sun protection factor (SPF) of the UV filter nanocapsules sunscreen improved by 300% compared with the free OD-PABA formulations. Moreover, OD-PABA encapsulated in the nanocapsules could reduce the cytotoxicity significantly through the evaluation of the sunscreen safety with MTT method.
TiO2 is widely used in cosmetic products but its poor dispersibility and photocatalytic degradation hazard still affect its performance. In this work, quaternized alkali lignin (QAL) is applied to encapsulate TiO2 by self-assembly and endows TiO2 excellent sunscreen performance and safety. Results show that the nano TiO2 particles were well trapped in lignin colloidal spheres (LCS) via hydrogen bonding. The LCS encapsulated TiO2 (LCS@TiO2) had a water contact angle as high as 89°, in comparison to only 22° of the TiO2 disk control sample. Thus the compatibility with the hydrophobic cream was improved. The photocatalytic activity of TiO2 could be effectively eliminated after modification. The dark color of QAL was significantly whitened by trapped TiO2. When the ratio (w/w) of LCS to TiO2 was 0.5, the LCS@TiO2 present the best synergistic effect, the sun protection factor(SPF) value of the cream containing 25 wt% LCS@TiO2 reached 84.82.
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Photosynthesis of previtamin D3 can occur throughout the epidermis in the dermis when hypopigmented Caucasian skin is exposed to solar ultraviolet radiation. Once previtamin D3 is formed in the skin, it undergoes a temperature-dependent thermal isomerization that takes at least 3 days to complete. The vitamin D-binding protein preferentially translocates the thermal product, vitamin D3, into the circulation. These processes suggest a unique mechanism for the synthesis, storage, and slow, steady release of vitamin D3 from the skin into the circulation.
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Irregularities in the geometry of sunscreen films spread on rough areas, like skin, is often presented as being the main cause of the degree of UV absorption achieved by the UV filters that are inside. Until now, only the step film, a model invented by O'Neill, was simple enough to calculate UV data close to in vitro experimental data, after determination of a limited number of fraction areas with their corresponding thickness. However, such models are obviously too simple to represent a real situation. In the present work, more complex distributions of film thickness were calculated, with an infinite number of individual heights. Realistic models were achieved via a probability function. The consequences for UV absorption were deduced, and the calculated UV data were compared to experimental in vitro data on sunscreen products measured after being spread on a roughened PMMA substrate. The latter substrate was previously selected for its ability to achieve a good correlation with in vivo SPF. An optimized version of the continuous mathematical model was finally determined in order to achieve UV curves, similar in shape and intensity to the experimental ones. The latter model can be used to predict realistic SPF values.
The potential ability of nine sunscreen preparations to prevent erythema was assessed by two commonly used in vitro methods—the thin-film technique and the dilute-solution method—as well as by a new in vitro method—the hairless mouse procedure. The study indicates that there are serious deficiencies in these first two methods when their results are compared to those obtained from in vivo testing. These two spectrophotometric methods predicted a much higher decree of effectiveness than was obtained under in-use conditions. The new in vitro method described here that uses the excised epidermis of the hairless mouse gave results comparable to those obtained in human volunteers.
Sunscreen agents are commonly used in cosmetic products to filter out noxious radiation in sunlight. A convenient high-performance liquid chromatographic (HPLC) method for the quantification of five sunscreens after irradiation has been selected. We used this analytical method to compare the photostability of benzophenone-3, PEG-25 PABA, octyl dimethyl PABA, 4-methylbenzylidene camphor and butyl methoxydibenzoylmethane, at levels in the range of 25-60 microM. The assay was carried out, using a C8 column with a methanol--water mobile phase. The detector was set at a wavelength of 300 nm. The assay was linear with the following limits: 0.2 microgram ml-1 for benzophenone-3, 1 microgram ml-1 for PEG-25 PABA, 0.15 microgram ml-1 for octyl dimethyl PABA, 0.1 microgram ml-1 for methylbenzylidene camphor and 0.05 microgram ml-1 for butyl methoxydibenzoylmethane. The half-lives calculated indicate a very good photostability of the sunscreens studied and permit to classify amongst themselves.
This article summarizes the current position on primary prevention of melanoma, including what is the evidence relating sunlight exposure to the development of melanoma, what forms of photoprotection there are and what are their relative values. There have been increasing incidence and mortality rates due to melanoma in most countries where they are being recorded. The initial approach in many countries has been to develop some form of early detection program in an attempt to diagnose and treat at a curable stage the melanomas that are occurring now. Primary prevention of melanoma is the more long term approach to the problem which many countries are now considering and a number are actively pursuing. Recent concern about stratospheric ozone depletion has contributed to the desire for the primary prevention approach. There are epidemiological data associating the risk of melanoma with increased exposure to sunlight in people with fair skin. They show that it is sunlight exposure in childhood and in doses sufficient to cause sunburn remembered many years later, that is particularly associated with risk of melanoma in adulthood. The exact spectrum of radiation in sunlight which is responsible for these tumours is not known, although the ultraviolet range is believed to be most important, particularly UVB but probably also UVA. The approach to photoprotection is a reduction in the overall exposure to sunlight, not just a single component of it. The natural protection of shade, clothing and hats is promoted as the best protection. Sunscreens have assumed a major component of primary prevention programs based on their convenience of use and also on their widespread promotion by those people who have a commercial interest in them. These products protect predominantly in the UVB range for which there is a sun protection factor (SPF) grading, as well as having some activity in the UVA range (for which there is not yet a satisfactory grading method).
The penetration of different wavelengths of UV radiation through human skin is of major importance, especially for the determination of photoprotective properties of sunscreens and UV-protective clothes. In this study we present a new method for the measurement of UV transmission through small skin specimens. The transmission measurements were performed by using a UV spectrophotometer with an integrating sphere operating in the wavelength range of 280-390 nm. For the skin samples, special quartz glass cuvettes were developed which allowed measurements for very thin and small skin specimens. Furthermore, the cuvettes prevented dehydration of the specimens and guaranteed, by using an additional diaphragm, that the transmission data were derived solely from the small skin specimen examined. Specimens measuring 8 x 3 mm(2) with a thickness of 0.3 mm (histometric and sonographic control) were taken from the thighs of 10 subjects via shave biopsy. In the UVA range (315-390 nm) we obtained a mean transmission of 4.6% and for the UVB range (280-315 nm) of 0.9%. No significant (p >0.14) difference of UV transmission was found between the individual skin specimens. This new method seems to be well suitable for UV transmission measurements of small skin specimens. As UVA radiation has a much deeper penetration depth and in in vivo situations dermal hemoglobin could have an effect on UV penetration, the present method is better suitable for the investigation of UVB-induced biological adaptation mechanisms and the impact of topical agents on UVB transmission of the epidermis.
With the aim to know the remanence of two sunscreens, PEG-25 PABA and benzophenone, two cases have been considered: the application of aqueous solution of two filters studied for the application of oil-in-water (O/W) emulsions containing the same two filters on the skin of 21 voluntary women. In order to determine the quantity of filter remaining in the stratum corneum after times of application, which vary from 1 to 7 h, a series of six strippings have been carried out. The sunscreen agents were assessed by HPLC. With this study, it has been possible to emphasize the best remanence of benzophenone 4. Moreover, the incorporation of photo-protective agents in a O/W emulsion promotes their penetration, and this is particularly due to benzophenone 4.
Although most health scientists now agree that health risks to the skin (e.g., skin cancer) exist from exposure to the ultraviolet radiation in sunlight, a scientific consensus has not really been achieved vis-à-vis sunlight and ocular health. A growing number of scientists warn of hazards to the eye if ultraviolet radiation - and perhaps even shorter wavelength visible radiation also - is not filtered by lenses. Despite a substantial literature on the adverse effects of ultraviolet radiation (UVR) and intense light upon ocular structures, particularly upon the retina, controversy still surrounds the question of whether the levels of natural and man-made light sources are damaging when encountered under normal viewing conditions. Although scientific evidence accumulates to indicate that chronic exposure conditions may accelerate ageing processes in ocular tissues, the quantitative question of "How much is safe?" remains to be answered conclusively.
Wearing of clothing, hats, and sunglasses to protect from exposure to sunlight should be part of a package of protection. Clothing specifically designed to avoid exposure is now available and recently standards have been published in several countries to measure the degree of protection. The ultraviolet protection factor (UPF) is likely to be as ubiquitous in clothing aisles as the sun protection factor (SPF) is now in the sunscreen aisle of your local department store.
Every living organism on the surface of the earth is exposed to the ultraviolet (UV) fraction of the sunlight. This electromagnetic energy has both life-giving and life-endangering effects. UV radiation can damage DNA and thus mutagenize several genes involved in the development of the skin cancer. The presence of typical signature of UV-induced mutations on these genes indicates that the ultraviolet-B part of sunlight is responsible for the evolution of cutaneous carcinogenesis. During this process, variable alterations of the oncogenic, tumor-suppressive, and cell-cycle control signaling pathways occur. These pathways include (a) mutated PTCH (in the mitogenic Sonic Hedgehog pathway) and mutated p53 tumor-suppressor gene in basal cell carcinomas, (b) an activated mitogenic ras pathway and mutated p53 in squamous cell carcinomas, and (c) an activated ras pathway, inactive p16, and p53 tumor suppressors in melanomas. This review presents background information about the skin optics, UV radiation, and molecular events involved in photocarcinogenesis.