Titanium dioxide and zinc oxide minerals are naturally occurring minerals frequently used in sunscreens to physically block harmful UV rays.
However, despite their high functionalities, these ingredients can cause a sunscreen formulation to be thicker in texture. Furthermore, it can leave the dreaded ‘white cast’ on skin, making it less suitable for individuals with darker skin tones.
Shiseido explained that with the company’s conventional methods, high amounts of titanium dioxide or zinc oxide powder need to be added to obtain a high level of protection. However, this would invariably lead to a thicker texture and more a noticeable white layer on the skin.
“While UV protection powder has a high UV protection effect and is water-resistant, it causes a feeling of film on the skin and a white cast, so it is better to use a small amount in terms of usability.”
This is because dispersing powder-type UV filters in oils, for instance, tend to cause the powder to agglomerate.
Therefore, Shiseido believed it was necessary to improve the dispersion of powder-type UV filters,
“There has been a demand for a technology that stably blends powder with strong cohesive power into sunscreens. We were able to achieve a stable dispersion state by effectively blending the dispersion component developed in-house with the UV protection powder and performing a special treatment at high pressure.”
Researchers tested two sunscreens with the exact same components but treated with different dispersion methods.
Under the microscope, the team observed that the powder treated with the newer method, dubbed the Smooth Protect Technology, was finer and more finely dispersed in the formula.
Furthermore, it was 2.9 times stronger in terms of sun protection compared to the conventional formula.
To measure the ‘feel’ of the formula, Shiseido utilised a tactile sensor it developed that measures the vibration and friction when applying a product on the skin.
By comparing the measurements, the researchers concluded that its Smooth Protect Technology was able to improve the sensorial effects of a sunscreen formula and give it a ‘bare skin feel’.
Lastly, the researchers compared both formulas against a black acrylic board and concluded that the Smooth Protect Technology could greatly reduce the opacity of a sunscreen formula, therefore reducing the incidence of ‘white cast’ on skin.
An advancement in sun protection tech
Shiseido concluded that with Smooth Protect Technology, it will be able to develop products with the same high levels of UV protection without copious amounts of titanium dioxide and zinc oxide.
“Smooth Protect Technology can provide new value to customers who demand high UV protection, as well as comfortable feel and a non-whitening appearance after application.”
The Smooth Protect Technology is the latest in a line of innovative sun protection technologies developed by Shiseido.
In 2014, the company developed WetForce Technology, which creates a more uniform UV shield on the skin when the formula interacts with water or perspiration, boosting UV protection by about 120%
Early last year, Shiseido debuted HeatForce Technology, which also creates the same effect when the skin’s surface temperature reaches 37°C.
Creating a more even spread on the skin is key as sunscreen formulas are most effective when they are molecularly uniform.
On January 19, Shiseido announced that it will be debuting Smooth Protect Technology under its Anessa sun care brand from February 21.