SUN CARE
Materials and methods The sunscreen formulations were prepared by Lott Research Incorporated of Ormond Beach Florida and tested by Florida Suncare Testing Incorporated of Ormond Beach Florida.14
Sunscreen formulations
were tested for SPF using a single port Solar Light Model 15S Xenon Arc Solar Simulator Lamp. This has a continuous light spectrum in the UVA and UVB spectrum (290 nm to 400 nm). The spectral output of the solar simulator is filtered so that it meets the spectral output requirements for testing sunscreen drug products for over-the-counter human use.15,16
Results and discussion To test the SPF increase of sunscreen formulations with the addition of Spider Ester ESO (sorbeth 2 hexaoleate), a series of formulations (Tables 2 and 3) were prepared and the sets of formulas were SPF tested on the same subjects. Formulations 1 and 2 were prepared in the US by a research consultant and tested in an independent test laboratory. Formulations 3-5 (Table 2) were prepared by SurfaTech Corporation and tested by an independent test laboratory. Table 3 shows the results of Formulations 1-5. Sorbeth 2 hexaoleate provides dramatic effect upon the SPF when used in different types of formulations. Formulations having the same concentration of actives but varying concentrations of sorbeth 2 hexaoleate, have drastically different SPF values. The organic filters, when loaded into the core of sorbeth 2 hexaoleate, come into intimate contact which leads to
Table 3: Results of Formulations 1-5. Formulation 1
% ESO 0.0
2 3 4 5
5.0 0.0 7.6
22.8
SPF 19
32
14.8 19.3 30.2
Table 4: SPF increase with the increase in sorbeth 2 hexaoleate. Ingredient
Sorbeth 2 hexaoleate (%) SPF
Increase of SPF (%)
Formulation 3 0.0
14.8 –
more efficient absorbing of photons thus leading to a higher SPF value. This intimate contact will also provide better transfer of excited state electrons, thus providing better photostability.
The uniformity of the SPF values developed on formulations made and tested by two different labs, one in North America and the other in Europe, is both unexpected and very important. It is well known in the industry that different testing laboratories can obtain significantly different results on the same formula. With this in mind, it is important to note that the SPF results from each separate test 1, 2, and 3 were obtained from the same subjects. For example, the same five subjects tested by the same clinicians obtained an average SPF of 19 on Formulaion 1 and an average SPF of 32 on Formulation 2.
Formulation 4 7.6
19.3 30.4
Formula type OW emulsion
OW emulsion Oil Oil Oil
Formulation 5 22.8
30.2 104.1
Figure 3b certainly suggests a linear relationship between increasing the sorbeth 2 hexaoleate concentration and increasing SPF. If a slope is calculated, it could be projected that the SPF might keep increasing to an astronomical number if the sorbeth 2 hexaoleate is increased to a high level. As shown in Figure 3b, the SPF value for an oil-based sunscreen formulation increased by 104.1%. To test the wavelength shift of sunscreen actives in formulations with the addition of a series of spider esters were tested including: Spider Ester ESO (Sorbeth 2 hexaoleate), Spider Ester AB-1 (glycereth 9 monococoate), and Spider Ester ABN (sorbeth 2 monoleate sorbeth 2 pentaoleate cross polymer [proposed INCI Name]). A series of four sunscreen formulations were prepared with altering solvents to test the wavelength shift.
Please visit us at in-cosmetics Barcelona, Booth # F58
April 2012 PERSONAL CARE
103
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