piperidines and oxybenzone

Concurrent application of insect repellent picaridin or DEET with sunscreens has become prevalent due to concerns on West Nile virus and skin cancer. The objectives of this study were to characterize the percutaneous permeation of picaridin and sunscreen oxybenzone from commercially available preparations and to compare the differences in permeability between picaridin and DEET in association with oxybenzone. In vitro diffusion studies were carried out to measure transdermal permeation of picaridin and oxybenzone from four different products, using various application concentrations and sequences. Results were then compared to those of repellent DEET and sunscreen oxybenzone under identical conditions. Transdermal permeation of picaridin across human epidermis was significantly lower than that of DEET, both alone and in combination with oxybenzone. Concurrent use resulted in either no changes or suppression of transdermal permeation of picaridin and oxybenzone. This finding was different from concurrent use of DEET and oxybenzone in which a synergistic permeation enhancement was observed. In addition, permeation of picaridin, DEET and oxybenzone across human epidermis was dependent on application concentration, use sequence, and preparation type. It was concluded from this comparative study that picaridin would be a better candidate for concurrent use with sunscreen preparations in terms of minimizing percutaneous permeation of the chemicals.

Topics: Benzophenones; Chromatography, High Pressure Liquid; DEET; Diffusion; Diffusion Chambers, Culture; Drug Combinations; Drug Synergism; Humans; In Vitro Techniques; Insect Repellents; Piperidines; Skin Absorption; Sunscreening Agents

Picaridin and oxybenzone are two active ingredients found in repellent and sunscreen preparations, respectively. We performed a series of in vitro diffusion studies to evaluate the transmembrane permeation of picaridin and oxybenzone across human epidermis and poly(dimethylsiloxane) (PDMS) membrane. Permeation of picaridin (PCR) and oxybenzone (OBZ) across human epidermis was suppressed when both active ingredients were used concurrently; increasing concentration of the test compounds further reduced the permeation percentage of picaridin and oxybenzone. While permeation characteristics were correlative between human epidermis and PDMS membrane, permeability of PDMS membrane was significantly larger than that of human epidermis. The findings were different from concurrent use of repellent DEET and sunscreen oxybenzone in which a synergistic permeation enhancement was observed. Further comparative studies are therefore needed to understand permeation mechanisms and interactions between picaridin and oxybenzone.

Topics: Benzophenones; Diffusion; Dimethylpolysiloxanes; Epidermis; Humans; Insect Repellents; Membranes, Artificial; Permeability; Piperidines; Skin Absorption; Sunscreening Agents