EFFECTS OF AFTER-SHAVE LOTIONS ON SKIN FLORA 757 the skin flora immediately after application. h•hibition is very evident at the two, four and six hour marks, rising to only 25% of the original count at the end of the test period. Although solution//6, the only one of this group which contains perfume, shows greater inhibition than the others, the difference is not significant, and these lotions should be considered as having equal effects. Commercial after-shave lotions present a varied picture, as shown in 40.-- 30-- •o i 2 3 4 5 6 Time in hours Figure 8.--Face Plate Counts--Test solutions with addition of hexachlorophene. Fig. 9. In the main, they follow the in vitro test results, with Lotion "B," the most effective, once again having the greatest activity. Lotions "A" and "E" which gave similar results in the serial dilution and zone of inhibi- tion tests showed a divergence at the conclusion of the test at six hours. On the other hand, Lotion "C," which was significantly more active than Lotion "D" in the in vitro testing, produced approximately the same effect on the skin. Figure 10 summarizes the in vivo results obtained with the various lotions and solutions. The effect of the addition of perfumes and antimicrobial agents to after-shave lotions can be clearly seen. The upper curve repre- sents the solutions without perfume. The skin flora has returned to the pre-application level after six hours. The center curve, combining commer- cial lotions and solutions with perfume, shows a continued inhibition or reduction of skin flora after six hours at a level 40% below the non-perfume

7.58 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS containing solutions. The addition of hexachlorophene, indicated by the bottom broken line, reduces the level of skin flora even fhrther to approxi- mately 75% below the original count after six hours. 80 70 '• 60 o .c_ 50 0 '3 40 20 I0 ' 0 i 2 3 4 5 Time in hours Figure 9.--Face Plate Counts--Commercial after shave lotions. SUMMARY In vitro and in vivo test methods have been presented to show the ability of perfumes in after-shave lotions to reduce or inhibit the growth of skin flora. No attempts have been made to delineate the action of individual per- fume components since previous investigators have defined the relative activities of many essential oils and aromatic chemicals.