Lab Lessons—Wise Words from the Bench with Paul Thau

By: Katie Schaefer, Cosmetics & Toiletries magazine

Posted: May 2, 2011, from the May 2011 issue of Cosmetics & Toiletries.

page 3 of 4

C&T: What tip can you give formulators as they begin to make products?
It is imperative, when possible, to conduct pre-formulation work since it is an opportunity to choose ingredients and make selections systematically. Chemists are only given a limited time to develop a formulation, so when time is available, it is key to do exploratory work. At Cosmair, I was able to develop a method to stabilize vitamin C in formulations; a good amount of that work had to do with interacting in the industry to find out what had been done previously and what was available from suppliers. Our group did some work with an anhydrous formulation technique and found that a silicone vehicle (g/s vehicle) could stabilize vitamin C.

C&T: What products do you find the most difficult to formulate and why?
It used to be that w/o emulsions were the most challenging and they were limited due to aesthetics; however, special emulsifiers have been developed that have made this easier. For instance, today’s silicone emulsifiers allow formulators to make some sophisticated w/o emulsions. This is aided by high energy emulsification processing. Microfluidics can be used to produce sprays with high petrolatum content systems. There is always the next frontier and no one person can keep up with the myriad of new developments.

C&T: What is one of the biggest formulating mistakes you have made?
[Fox] and I were formulating a hair dressing based upon a carbomer and a simple preservative in an unlined aluminum package, and neither he nor I could figure out why the formulation was corroding the aluminum tube. The trace preservative (.003% methialate) was catalytically creating a reaction and liberating hydrogen, decomposing the aluminum. We needed an alternate preservative.

C&T: What advice can you offer novice formulators regarding testing?
No matter how simple the formulation, you need to conduct complete testing. Again, when I was at Cosmair, another company took one of our formulations and reformulated it with another emollient to serve as the pressing agent. The product was produced and distributed globally but in cold areas, the pressed tablets were exploding. As it turned out, the cosmetic company had used the emollient isopropyl stearate palmitate without blending it with an anti-freeze agent. When the oil used as the compression agent was frozen, it solidified. Even with a pressed powder, you need to put it through freeze-thaw cycle.

C&T: What technology has revolutionized cosmetic formulating?
Silicone technology has definitely changed the personal care industry. Cyclomethicones have made it possible to develop many more elegant formulations.