SUN CARE


These formulations were tested for absorbance in the UVA and UVB range. This study is based on the improvement of the UVA region of the spectrum. Figure 4 shows the absorbances of the four formulations in the high UVA range (370 nm to 400 nm).


Several factors were compared including critical wavelength, UVA/UVB ratio, and increase in UVA (370 nm to 400 nm). The results are summarised in Table 5. Formulations 6-9 show a shift of absorbance closer to 400 nm. The UVA to UVB ratio increased from 0.86 to 1.09. This ratio can be a little misleading because spider esters also boost the UVB portion of the spectrum. In order to determine the increase in UVA spectrum, the absorbance from 370 nm to 400 nm was compared. Mineral oil (Formulation 6) was used as a standard. The absorbance of the spider ester formulations from 370 nm to 400 nm was divided by the absorbance of the mineral oil. The spider ester formulations showed an increase in the absorbance between 370 nm to 400 nm by 66.93%.


Conclusion


Spider esters are amphiphilic polymers that can be used to encapsulate small molecules into the core. The actives or small molecules inside the core are held in intimate contact with the polymer, this provides: a boost in SPF, the actives can stabilise into more polar forms which can shift the wavelength (λ), and the encapsulation of the actives can shield any taste, colour or odour associated with the actives.


The encapsulation of organic filters in a wide variety of sunscreen formulations provides improvement in SPF and a shift in the absorbance towards 400 nm. Spider ester in a sunscreen formulation, with organic filters, shows a dose dependent response when the concentration of Spider Ester ESO (sorbeth 2 hexaoleate) is altered. As seen in Table 4, the SPF of an oil-based sunscreen formulation was increased from 14.8 to 30.2 (in vivo). While the sunscreen formulations were not optimised to achieve maximum SPF, the spider esters provide the ability to increase the SPF of a formulation by 104.1%. Spider Esters ESO provides the ability of sunscreen formulation to decrease the amount of actives and maintain the same SPF value. Also, as seen in Table 6, spider esters can be used to shift the absorbance of typical organic filters. Spider Ester ABN was shown to increase the absorbance from 370 nm to 400 nm by 66.93 %.


Spider esters are very versatile polymers and can be used to improve sunscreen formulations in many different aspects. The wide variety of spider esters provide a way to maximise the performance of sunscreen


104 PERSONAL CARE April 2012


References 1 Lademann J, Rudolph A, Jacobi U et al. Influence of nonhomogeneous distribution of topically applied UV filters on sun protection factors. J Biomed Opt 2004; 9 (6): 1358-62.


2 Beattie PE, Dawe RS, Ferguson J, Ibbotson SH. Dose-response and time-course characteristics of UV-A1 erythema. Arch Dermatol 2005; 141 (12): 1549-55.


3 Bonda C, Steinberg D. Cosmetics & Toiletries 2000; 115: 37-45.


4 US7723456 entitled: Crosslinked silicone polymers based upon Spider esters. Issued to O’Lenick et al. Assigned to SurfaTech Corporation.


5 US7569607 entitled: Spider esters in personal care applications. Issued to O’Lenick et al. Assigned to SurfaTech Corporation.


6 US7473707 entitled: Spider esters in personal care applications. Issued to O’Lenick et al. Assigned to SurfaTech Corporation.


1.4 1.2 1.0 0.8 0.6 0.4 0.2 0


370 380 Wavelength (nm) Figure 4: The absorbance of formulations. 390


Table 5: Formulations 6-9. Ingredient


Mineral Oil


Spider Ester ESO Spider Ester AB-1 Spider Ester ABN Octocrylene Octisalate


Avobenzone –


% w/w


Formulation 6 Formulation 7 Formulation 8 Formulation 9 89


– – –


3 5 3


Table 6: Results of Formulations 6-9. Formulation 6


7 8 9


377.3 379.5 377.2


formulations. The ability of decreasing the amount of small molecule organic filters and adding large polymeric materials will lead to better consumer products.


89 – –


3 5 3


– –


89 –


3 5 3


– – –


89 3 5 3


Critical Wavelength (λ) 373.4


UVA/UVB 0.86


1.00 1.09 1.06


Increase in λ370–400 –


47.12 60.82 66.93


7 US7462729 entitled: Spider esters in personal care applications. Issued to O’Lenick et al. Assigned to SurfaTech Corporation.


PC


8 US Patent Application 20090253812 entitled: Spider esters as delivery systems. Issued to O’Lenick et al. Assigned to SurfaTech Corporation.


9 de Gennes PD. Scaling concepts in polymer physics. Ithaca, NY: Cornell University Press, 1979.


10 O’Lenick T, Lott D. Cosmetics & Toiletries 2010; 6: 430-6.


11 http://en.wikipedia.org/wiki/Beer%27s_law 12 Shaath N. J Soc Cosmet Chem 1987; 82: 193-207.


13 Agrapidis-Paloympis L, Nash RJ. Raman Spectrosc 1987; 38: 209-21.


14 http://flsuncaretesting.com/ 15 Spectral output requirements for testing sunscreen drug products for over-the-counter human use. Proposed amendment of final Monograph, CFR Part 352. 70 (b) Light sources, Federal Register 72, 165 (Aug 27, 2007).


16 International sun protection factor (SPF) test method. www.colipa.eu/downloads/86.html


(%)


■ Formulation 6 ■ Formulation 7 ■ Formulation 8 ■ Formulation 9


400


Absorbance


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88  |  Page 89  |  Page 90  |  Page 91  |  Page 92  |  Page 93  |  Page 94  |  Page 95  |  Page 96  |  Page 97  |  Page 98  |  Page 99  |  Page 100  |  Page 101  |  Page 102  |  Page 103  |  Page 104  |  Page 105  |  Page 106  |  Page 107  |  Page 108  |  Page 109  |  Page 110  |  Page 111  |  Page 112  |  Page 113  |  Page 114  |  Page 115  |  Page 116  |  Page 117  |  Page 118  |  Page 119  |  Page 120  |  Page 121  |  Page 122  |  Page 123  |  Page 124  |  Page 125  |  Page 126  |  Page 127  |  Page 128  |  Page 129  |  Page 130  |  Page 131  |  Page 132  |  Page 133  |  Page 134  |  Page 135  |  Page 136  |  Page 137  |  Page 138  |  Page 139  |  Page 140  |  Page 141  |  Page 142  |  Page 143  |  Page 144  |  Page 145  |  Page 146  |  Page 147  |  Page 148  |  Page 149  |  Page 150  |  Page 151  |  Page 152