Resistance of Liposomal Sunscreen Formulations against Plain Water as well as Salt Water Exposure and Perspiration

The present in vivo investigation using a total of 30 healthy adult
volunteers with Fitzpatrick skin type II examines the persistent
efficacy of sunscreens using liposomal suspensions as the vehicle.
Based on the COLIPA guidelines, the protective effect of a single
application of 4 different liposomal sunscreen formulations (sun
protection factors, SPFs: 50+, 30,25 and 15) against sunburn at the
recommended amount of 2 mg/cm(2) was determined after exposure of
the skin to plain water and salt water and after profuse
perspiration. Under the influence of plain water, salt water and
sweating, the SPF values of sunscreen 1 (labeled SPF of 50+) were
reduced only marginally to 97, 96 and 99%, respectively, those of
sunscreen 2 (labeled SPF of 30) to 97, 96 and 99%, respectively,
those of sunscreen 3 (labeled SPE of 25) to 90, 83 and 91%,
respectively, and those of sunscreen 4 (labeled SPF of 15) to 96,
96 and 95%, respectively. This set of data shows that despite plain
water and salt water immersion or profuse sweating, the liposomal
sunscreen formulation may deliver a long-lasting protective effect
in everyday situations encountered by outdoor workers or during
leisure activities. Copyright (C) 2010 S. Karger AG, Basel