FACTORS ON THE FORMATION OF COSMETIC EMULSIONS 49 MR. DENAVARRE: How large was the batch? DR. SPr. RAND•O: The batch we used was 1000 gm. lots. MR. KLApp: I would like to know if you placed the Span 80 and Tween 80 in the water phase or the oil phase. DR. SPr. RANDIO: Each emulsifying agent was placed in its selective phase. MR. DF.N^v^RRE: You mentioned one batch in which you threw every- thing in together, heated it, and then put it under the mixer. How did it come out ? DR. SPERANDIOi That was interesting. On that particular formula I was surprised at how it did come out, because it came out, as I said earlier with a viscosity midway between the two extremes. On over-all particle size distribution it came out practically to the identical pattern as those which we mentioned that had been mixed in the conventional way. In over-all stability on all of the factors which we studied, it came out third or fourth, out of the seven. And I believe--I am quite sure--by modifying it we could have gotten it better. MR. ALEXANDER: Was any work done in order to determine whether the emulsion, on standing, became more or less hydrophilic, assuming it was a water-in-oil emulsion ? DR. SPERANDIO: More or less. MR.. ALEX^NDEP,: Did the hydrophilic nature change? DR. SPERANDIO-' I might say that we made sure it was an oil-in-water emulsion at the beginning, by using selective soluble dyes but after the first test we did not make any further determinations on that particular factor. In fact, we didn't touch them, just let them stand and observed them. MP,. MINTON: What was the quantitative formula of the emulsion ? DR. SPERANDIOi I'll be glad to read that to you. CI•^IRM^N S^G^RIN: That will be in the printed paper, and it would have been on a chart, had the charts been available on slides. DR. SP•.R^Nmo: The formula, briefly, calls for heavy mineral oil, 350-- and, this is all by weight in grams--lanolin anhydrous, 10 cetyl alcohol, 10 Span 80, 21 Tween 80, 49 and distilled water, 560. I might say that when we made this formula we did not want to have a perfect emulsion, assuming we could have made one. We wanted to be able to study improvements as well as degradations. MR. S^G^RIN: If there are no other questions, Dr. Sperandio, to what extent, from other work that you have done, are you willing or ready to generalize with the results that you have obtained from this emulsion, on emulsions generally? On other oil-in-water emulsions which contain dif- ferent emulsifying agents? And so on. DR. SPEtt^sDIO: To generalize, about the most positive statement I could make is that to me there is nothing positive about the emulsions. I believe

50 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS that probably this work would hold true only for this type of formula, and that every individual formula would be an individual problem in itself. Generalizing, though, from the results of this work and other work that we have done, ! am convinced that for making this type of emulsion the best procedure is to pour the aqueous phase into the oil phase. ! have always liked that, although I know some textile authorities like the reverse method we also felt that the speed of stirring is probably a most important factor in the over-all emulsion formula.