752 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS TAm, V: III--ZoNF•S ov INHIBITION (MM.) Solutions Plus 0.25% Hexachloro- phene U.S.P. Face Staphylococcus gillus Penicillium Bacteria /lureus Niger Sp. Candida /llbicans Solution #1 32 26 5 6 3 Solution #2 30 25 8 5 3 Solution #3 30 23 3 4 3 Solution #4 32 23 6 8 4 Solution #5 30 24 7 6 3 Solution #6 32 23 8 8 4 Solution #7 32 25 8 8 4 Solutions Plus 0.10% Benzalkonium Chloride U.S.P. TABLE IV--ZONES OF INHIBITION (MM.) Penicillium /lsper- Face Staphylococcus gillus Bacteria /l ureus Niger Candida /llbicans Solution #1 16 9 1 7 9 Solution #2 17 9 2 7 10 Solution #3 16 9 1 6 9 Solution #4 16 10 2 7 8 Solution #5 16 10 6 7 8 Solution #6 19 10 7 8 8 Solution #7 19 10 7 8 8 TABLE V--ZONES OF INHIBITION (MM.) Commercial After-Shave Lotions Face Staphylococcus ztspergillus Bacteria /lureus Niger Penicillium Candida /llbicans Lotion "A" 3 2 1 0 2 I.otion "B" 27 13 4 4 8 Lotion "C" 17 13 2 0 2 Lotion "D" 7 3 2 0 3 Lotion "E" 2 2 0 0 1 TABLE VI--SEKIAL DILUTIONS Solution #1: water and ethyl alcohol Solution #2: water, ethyl alcohol and benzyl alcohol Solution #3: water, ethyl alcohol and propylene glycol Solution #4: water, ethyl alcohol, benzyl alcohol and P. G. Solution #5: water, ethyl alcohol, benzyl alcohol, P. G. and 0.75% perfume Solution #6: water, ethyl alcohol, benzyl alcohol, P. G. and 1.5% perfume Solution #7: water, ethyl alcohol, benzyl alcohol, P. G. and 3.0% perfume 1 2 3 4 5 I+ + -- 6 7 8 9 10 11 12 + + + + + + + + + + + + + + + + + + + + + + + + + + + + -I+ + + + + + - - + + + + + _ _ + + + + +

EFFECTS OF AFTER-SHAVE LOTIONS ON SKIN FLORA 753 incubated at 37øC for forty-eight hours before reading. When observing these tubes it is very important to distinguish between the cloudiness due to growth and the cloudiness which may be caused by a precipitation of the perfume or other water-insoluble materials from the shave lotions or solu- tions. Where there was a doubt as to whether or not growth appeared, sub-cultures were made for confirmation. Table VI shows the results of the serial dilutions test for the seven "standard" lotions. The line drawn at the edge of the "no growth"- "growth" border graphically illustrates the relative activity of these lotions. Solution//1, containing only water and alcohol, had growth from tube 4 on. TABLE VII--SEkIAL DILUTIONS 1 2 3 4 5 6 7 8 9 10 11 12 13 15 (Con- 14 trol) Solutions plus benzalkonium chloride Solution #1 Solution #2 Solution #3 4- 4- 4- 4- 4- 4- Solution #4 + + + + 4- + 4- Solution #5 - Solution//6 - Solution #7 Solutions plus hexachloro- phene #1 through #7 ..... 4- Solutions //2, //3 and #4 containing the other additives showed growth starting in tube 5. A break point occurs at solution 5, containing 0.75% perfume, with growth starting in the 7th tube. With 1.5 and 3% perfume growth was evident from the eighth tube on. These tests showed no differ- ence in the growth pattern between the solutions containing 1.5 and 3% perfume. These serial dilution tests offer a precise method for measuring differences in activity of these various lotions and ingredients. The upper portion of Table VII shows the previously described seven solutions, this time with added benzalkonium chloride. Here the picture is similar to that with the lotions above except that the growth is delayed further on in the series. The lotions with perfume again show an added germicidal effect. The lower portion of this table gives the results obtained when hexa- chlorophene was added to the solutions. The activity of hexachlorophene overshadowed the action of the other ingredients, and all of the solutions were free from growth. The relative differences existing between the commercial after-shave lotions are depicted in Table VIII. Lotion "B," which performed best in the