Ultraviolet protective performance of photoprotective lipsticks: change of spectral transmittance because of ultraviolet exposure.

Background: Photoinstability of sunscreens because of ultraviolet (UV) exposure is a well-known and common phenomenon. Recently, it was also shown that sunscreens with complex filter combinations are photoinactivated by UV exposures, which can easily be acquired by solar exposure over several hours.

Objectives: To assess the change of the spectral transmission after UV exposure (UV-challenged protective performance) of 27 commercially available photoprotective lipsticks.

Assessment of thickness of photoprotective lipsticks and frequency of reapplication: results from a laboratory test and a field experiment.

Background: The thickness of the sunscreen layer that is actually applied by consumers under usual conditions has been determined for photoprotective lotions and creams; however, this question is still unanswered for photoprotective lipsticks.

Objectives: To assess lipstick thickness (area density) and frequency of application per day for two commercially available photoprotective lipsticks with different consistency.

Methods: The study consisted of a laboratory test and a field experiment.

Change of ultraviolet absorbance of sunscreens by exposure to solar-simulated radiation.

Regarding the outdoor behavior of the Caucasian population, modern sunscreens should provide high and broad-spectrum ultraviolet protection in the ultraviolet B as well as in the ultraviolet A range and should be photochemically stable for ultraviolet doses, which can be expected in solar radiation. At present an assessment of the photostability of suncare products is not a general requirement before marketing. In order to evaluate the photostability of suncare products we conducted an in vitro test and measured the spectral absorbance of 16 sunscreens before, and after exposure to increasing biologically weighted standard erythema doses (5, 12.