DETERMINING BACTERIOSTATIC POTENCY OF CHEMICALS Chart $.--Bacteriostatic Dilutions 405 "Dilution" Chemical "Zone-reduction" Method Method Phenylmercuric benzoate 1-5,000,000 to 1-10,000,000 1-10,000,000 Gentian Violet 1-2,000,000 to 1-5,000,000 1-5,000,000 Mercuric Chloride 1-500,000 to 1-1,000,000 1-1,000,000 Quaternary ammonium cpd. 1-500,000 to 1-1,000,000 1-1,000,000 Hexachlorophene 1-500,000 to 1-1,000,000 1-1,000,000 Acriflavine 1-300,000 to 1-600,000 1-500,000 8-Hydroxyquinolin sulfate 1-50,000 to 1-100,000 1-100,000 Hexylresorcinol 1-20,000 to 1-50,000 1-20,000 Chlorothymol 1-5,000 to 1-10,000 1-10,000 Phenol 1-20 to 1-50 1-200 cream, or whatever you are testing). ii?:i: The regulating factor, which de- the end-point (i.e., the bac- teriostatic dilution) is the relative •:• concentrations of the two com- ponent parts of the chemical teac- :!? tion involved (M-+-B) and not the point in a special artificial medium (agar) where the "M" and the "B" i:11::,.(chemical and bacteria) meet to react. SUMMARY AND CONCLUSIONS . : '!!7111 It has been the endeavor in prepar- ii:11:11' ing this paper to present first a brief over-all description of the phenom- ena of bacteriostasis, how it acts, how it may be made use of in the field of cosmetics, and how its rela- tive efficiencies and specific values can be determined. Finally we have presented a new method, simple to perform, usable for determining the correlative, as well as actual, bac- teriostatic potencies of chemicals. BIBLIOGRAPHY' (1) Cade, A. R., Soap and Sanitary Chem- icals, 111 (February, 1944) Ibid., 138 (April, 1947) y. oeact., 53,504 (1947). (2) Klarmann, E.G., and Wright, E. S., Soap and Sanitary Chemicals, 21, No. 1, 113, (1945) 22, No. 1, 125, (1946) and 22, No. 8, 139, (1946). (3) Stuart, L. S. Ibid., 135 (September, 1947) y. Assoc. Off. Agr. Chem., 401, (1949). (4) Cade, A. 12., Soap and Sanitary Chemi- cals (April, 1947). (5) Cade, A. R., 2•roc. Sci. Section Toilet- Goods Assoc., 16 (May, 1947) Ibid., 31 (May, 1948).

THE COSMETIC ASPECTS OF ESTROGENIC HORMONES By E,rL G. KLARVrANN, D.Sc. Vice-President in Charge of Research, Lehn and Fink, Inc., Bloomfield, N.J. A NU•BE• of different cos- metic preparations containing estro- genic hormones have been on the market for some thirteen years. During this period of time, a sub- stantial amount of clinical and other information has accumulated which bears either directly or indirectly upon the use of the estrogens in cos- metic formulations. In the follow- ing lines, an attempt has been made to review and to evaluate such evidence as is deemed to be relevant to the subject under consideration. THE ACTION OF COSMETIC Hov,- MONE CREAMS UPON THE SKIN Most cosmetic hormone creams, available on the market today con- tain from 7500 to 10,000 Interna- tional Units (I.U.) ofestrogenic sub- stance per ounce of' vehicle. This substance is usually of natural origin and consists essentially of estrone smaller proportions of alpha-estra- diol, equiline, and equilenin may be present in extracts from the urine of gravid mares which constitutes one of the most important sources of.this material. When applied in a cosmetic cream, this hormone potency may be safely regarded as being well below the threshold value for any systemic action. Assuming that a two-ounce jar of hormone cream with a total potency of 20,000 I.U. is used up over a period of one month, the in- dividual daily application would contain 666 I.U. It is known, how- ever, that absorption from an ex- ternally applied ointment does not take place to the extent of 100 per cent at best, it is not greater than 40 per cent, and usually consider- ably less. Therefore, a maximum absorption of 290 units should be taken into account, which certainly is far less than required for any sys- temic effect. According to the New and Nono2]i'cial Remedies (a publi- cation of The American Medical As- sociation), the therapeutic dose is 2000 to 10,000 I.U., by intramusct•- lar injection, one or more times weekly, depending on the patient's response. As much as 50,000 I.U. per week may be required in certain cases. Of course, intramuscular in- jection results in a practically corn- 406