389 SKIN PERMEATION OF HAZARDOUS COMPOUNDS 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 0 50 100 150 200 250 300 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0 50 100 150 200 250 300 0 1 1 2 2 3 0 50 100 150 200 250 300 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0 50 100 150 200 250 300 g415me (min) Finite dose Infinite dose Finite dose Infinite dose Finite dose Infinite dose Finite dose Infinite dose Figure 3. Concentration profile of selected hazardous organic compounds from cigarette smoke inside the simulation chamber measured by active sampling in finite (grey dots) and infinite (white dots) dose conditions. Nicog415ne ( L-1) Toluene ( L-) Ethylbenzene(μg L-1) p-cymene(μgL-1)

390 JOURNAL OF COSMETIC SCIENCE In vitro dermal absorption studies were performed using finite dose conditions, using control Strat-M® membranes without cosmetic (n=3) and membranes treated with a 2 mg cm−2 homogeneous layer of cosmetics A, B, and C (n=3). Modified Franz cells were introduced in the chamber, the three cigarettes were burnt, and the cells remained in the chamber during 135 min. Then, the concentration of target analytes was determined in Strat-M® membrane and receiving solution of each cell. Additionally, a reagent blank was also analyzed to check the absence of contaminations. The obtained concentrations in control experiments are shown in Figure 4 and Table IV. As it can be seen, nicotine was the only compound detected in the receptor solution, while much more compounds were detected in Strat-M® membrane, such as BTEX, sty- rene, p-cymene, and limonene. Nicotine concentration in the receptor solution increased with the time, reaching a maxi- mum concentration value at 30-min exposure time (11.6 µg L−1). Under these conditions, the effect of the evaluated cosmetics after 30-min exposure clearly decreases the nicotine dermal absorption with concentrations of 7.9, 6.6, and 7.5 µg L−1 for cosmetics A, B, and C, respectively, indicating an antipollution effect over nicotine absorption (see Table IV). Analysis of Strat-M® membrane in control studies after 30-min exposure provided concentrations of 90 ng cm−2 benzene, 160 ng cm−2 toluene, 55 ng cm−2 ethylben- zene, 400 ng cm−2 m+p-xylene, 120 ng cm−2 o-xylene, 160 ng cm−2 styrene, 71 ng cm−2 p-cymene, 500 ng cm−2 limonene, and 2,500 ng cm−2 nicotine. In the same way, application of cosmetics A, B, and C provided a significant reduction of the amount of target compounds in the membrane (see Table IV), being the antipollution effect confirmed. DERMAL ABSORPTION IN INFINITE DOSE CONDITIONS Antipollution effect of cosmetics was also evaluated at extreme situations, using infinite dose conditions performed by the combustion of three cigarettes every 30 min for a total time of 8 h. Under these conditions, the concentration of cigarette smoke components remain at high concentration levels for a long time (see Figure 3). Active sampling was carried out for a total time of 4.5 h with 20-min intervals, providing an average concen- tration after 30 min of 20 ± 5, 8 ± 2, 1.4 ± 0.3, and 0.7 ± 0.1 µg L−1 air for nicotine, toluene, ethylbenzene, and p-cymene, respectively. In the same way, in vitro dermal absorption studies at infinite dose were performed for control and cosmetics A, B, and C, using modified Franz cells for an exposure time of 0.5, 1, 2, 4, and 8 h. Benzene, toluene, and nicotine were detected after 1-h exposure time in the receptor solution of control tests (see Table V), with concentrations of 3.6, 4.8, and 29.0 µg L−1, which increased to 24, 33, and 1,800 µg L−1 after 8 h exposition, respectively. Figure 5A shows the concentration in the receptor solution with time, indicating a lin- ear uptake for nicotine, while benzene and toluene seemed to reach the equilibrium at 8 h. Concentration found in Strat-M® membrane of control experiments showed a linear uptake (see Figure 5B and Table VI) that reached the equilibrium after 4-h exposure, with concentration of 540 ng cm−2 toluene, 340 ng cm−2 ethylbenzene, 410 ng cm−2 p-cymene, and 49,700 ng cm−2 nicotine. Table VI shows the target compound concentration in Strat-M® membranes treated with cosmetics A, B, and C. The effect of the cosmetic layer over Strat-M® membranes was a