PRODUCT STABILITY--PART II 325 incandescent and fluorescent lamps and checked peroxide formation iodometrically it is known that aqueous zinc oxide may produce hydro- gen peroxide. They showed that the source of the zinc oxide and other ingredients influences the peroxide generation by the zinc oxide. They found that the increase in hydrogen peroxide concentration with time was not linear. In conclusion, we may note the fact that Bartels (70) has pointed out the possible utility of various types of quantitative microscopy in solving problems connected with cosmetic R&D work. In fact, speaking of parameters, he suggests that parameters which indicate a good correla- tion to the effect we wish to observe be created, regardless of whether they are common to the present scientific literature or not. CONCLUSION Early theoreticians and experimentalists have given us a heritage, part of which we recognize as the principles of what today is known as physi- cal chemistry. The seemingly necessary--or at least ever-present--pace of today has stimulated workers in the pharmaceutical industry to use some of this inheritance, namely that portion specifically pertinent to the present discussion, i.e., basic chemical kinetic concepts. The promise of tomorrow seems to be that even more of these techniques will be found to be applicable to product development efforts in the cosmetic industry. The thoughts expressed here concerning further progress in this direction have taken the form of suggestions based on a discussion of possible quantitative ways which monitor the changes formulations go through upon storage. Of course, more data are required before firm conclusions can be reached, but if work along this line is implemented, many ex- citing areas may be opened up for study. Certainly, our aim must be to do everything we can to enhance our knowledge of the "systems" we call "products." ACKNOWLEDGMENTS The author gratefully acknowledges the fact that Dr. R. F. Doerge, Professor of Pharmaceutical Chemistry at the College of Pharmacy of Oregon State University, brought to his attention references 6 and 7 describing the Japanese work on vitamin B•. The author also expresses his appreciation to Miss Lillian Capro for the secretarial work involved in the preparation of the drafts and of the final manuscript. (Received October 27, 1965)

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