Formulating High SPF Sun Care Products With A - External Factor ...
Formulating High SPF Sun Care Products With A - External Factor ...
Formulating High SPF Sun Care Products With A - External Factor ...
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SUN CARE<br />
LIQUID-MINERAL UV FILTER<br />
The inclusion of 3% Polysilicone-15 raises<br />
the <strong>SPF</strong> from 18 to 30 (A and B) and<br />
from 38 to 53 (C and D). This data are in<br />
line with many other experiments where<br />
it was found, that Polysilicone-15 exerts<br />
synergistic effects when combined with<br />
4-Methylbenzylidene Camphor (MBC),<br />
Phenylbenzimidazol Sulfonic Acid (PBSA)<br />
(19), Titanium Dioxide (TiO2). A possible explanation for these synergistic<br />
effects can be found<br />
1. In the film forming properties of Polysilicone-15<br />
2. Reduction of the aggregation of the<br />
traditional UV-filters<br />
3. Reduction of the agglomeration of<br />
pigments<br />
and thus supporting a better distribution<br />
of traditional UV-filters on the skin surface<br />
(Fig. 7).<br />
Thus, Polysilicone-15 can be used to exploit<br />
more efficiently the UV-absorbing<br />
potential of the traditional UV-filters.<br />
Low performance of Polysilicone-15<br />
in combination with EHMC<br />
Table 3 shows the unexpectedly low in<br />
vivo <strong>SPF</strong> results if EHMC is combined<br />
with Polysilicone-15. If EHMC is added<br />
to a standard sun care formulation with<br />
<strong>SPF</strong> 30 containing 3.0% Polysilicone-15<br />
the in vivo <strong>SPF</strong> decreased to 25. This initially<br />
surprising result can be caused by<br />
significant π-π interactions of the aromatic<br />
chromophoric systems (14). This interactions<br />
result from the similar structural<br />
features of the benzalmalonate chromophore<br />
and the EHMC chromophore<br />
leading to a energetically favored aggregation.<br />
As is known and has been discussed<br />
above, these interactions reduce<br />
the sun protection activity. Thus, it is not<br />
recommended to combine Polysilicone-<br />
15 with EHMC.<br />
� Further unique characteristics<br />
of Polysilicone-15<br />
<strong>With</strong> the structure of Polysilicone-15 given,<br />
some unique characteristics are implied<br />
which can not be found with other<br />
UV-filters, and which give additional<br />
benefits for the products and the consumers.<br />
Improved Sensorial Profile<br />
Having a polysiloxane backbone in the<br />
molecule, Polysilicone-15 exerts a silicone-like<br />
feeling when applied on the<br />
skin, especially compared to traditional<br />
mineral UV-filters. This new technology<br />
UV-filter shows specific advantages in<br />
the sensorial profile and the reduced<br />
residual whitening of the skin. To prove<br />
this advantages two similar sun care formulations<br />
were created (composition see<br />
Table 4). Formulation A contained 6%<br />
TiO 2 . In formulation B 3% of the TiO 2 was<br />
replaced by 3% Polysilicone-15. Both<br />
formulation achieved a comparable <strong>SPF</strong><br />
of 27 (A), respectively 28 (B). The replacement<br />
of TiO 2 by Polysilicone-15 had<br />
a considerable influence on the sensorial<br />
profile. The two formulations were analyzed<br />
at an external test institute where<br />
12 trained panellists quantified the sen-<br />
sorial profile of both formulations. Fig. 8<br />
shows the parameters where the most<br />
important differences were measured. It<br />
can be seen that the speed of absorption,<br />
the coolness, the melting and the ease of<br />
spreading were almost all significantly<br />
better for the formulation containing<br />
Polysilicone-15. The whitening during and<br />
after spreading was significantly reduced<br />
when 3% TiO 2 was replaced by 3% Polysilicone-15.<br />
The formulation containing<br />
Polysilicone-15 exerts the same protection<br />
of the skin as TiO 2 , but provides a<br />
formulation with a much better sensorial<br />
profile.<br />
Increased consumer protection<br />
The same two formulations as described<br />
above were used for the following consumer<br />
test at an external test institute:<br />
Fig. 7 Synergistic effect of Polysilicone-15 in combination with other UV-filter<br />
Fig. 8 Sensorial test: Comparison of application characteristics of a sun care<br />
formulation with and without 3% Polysilicone-15<br />
score<br />
14<br />
6 SÖFW-Journal | 131 | 7-2005