“If you always do what you always did, you will always get what you always got.” —Albert Einstein
Formulating at the bench level hasn’t changed much in the past 60 years—the theory of emulsions as used by the average chemist, for example, hasn’t progressed far beyond the principles found in a paper published in 1949. Chemists modify tried-and-true formulas or revert to tedious trial-and-error experiments to create (hopefully) stable and efficacious products. Familiar materials are used in customary ways; new ingredients are approached with extreme caution, because there is always the possibility of an unexpected or unwanted interaction with other materials.
However, there are new ways of doing things that can change R&D habits and product development in fundamental ways. This column has looked at several innovations in the past, and here we’ll put a few approaches together to provide a broad look at product creation at the cutting edge. Not every method is good for every product type, but a tool box of new ideas can surely jump start a sleepy development program. Innovation, often a risky proposition, can have a high likelihood of success if the underlying ideas are sound.
Considering New Materials; Using Them Efficiently
A new active material has been developed—from stem cells. Marie Alice Dibon’s article The Role of Stem Cells in Beauty—Today and Tomorrow, published by GCI in September 2011, serves as a starting point to understand the contemporary possibilities of these materials. The first step is to establish the efficacy of the new active. Here, genomics makes the process quick and relatively economical. A DNA microarray (gene chip) or polymerase chain reaction (RT-PCR) are two common approaches to establishing the mechanisms of action at a fundamental biological level.1 This takes the place of expensive clinical trials and shows exactly how the material accomplishes its mission.
Now the compatibility of the new material must be determined. We have previously looked at high throughput in this column space.2 Pioneered by Bob Lochhead, it is like trial-and-error on steroids. Robotic devices can make hundreds of samples a day, creating mixtures that may or may not be compatible. Some resultant properties, such as turbidity or tackiness, can be evaluated automatically. A computer is programmed to digest the information, and a phase diagram is produced. The phase diagram identifies good and bad areas relating to material interactions. Work on the bench is still necessary, but lab time is dramatically reduced.
In today’s lab, computer programs can be used to make important predictions of the properties of materials and mixtures. One program, for example, was designed for identifying the ideal solvent or solvent blend for polymers. Databases are also available to extend the applications into other personal care areas, such as fragrance or emollients. A well-designed software program goes a long way to determining what will or will not work, and makes predictions on many other properties, from vapor pressure to skin permeation.
A recent program commercialized3 by the late Johann Wiechers extends concepts and truths of how materials interact more specifically into cosmetic formulation, skin permeation, and the delivery of cosmetic and pharmaceutical actives. In “Formulating for Efficacy,” Wiechers concentrated on the solubility properties of the active and the vehicle.4 He identifies opposing solubility factors that allow the minimal amount of active to provide maximum delivery.
To be ideal, the outcome—the product—must meet three criteria: The active must be capable of penetrating human skin; the molecule must have the right activity profile; and it must be in the correct formulation. When the chemical structure of the active is entered into the software, an ideal set of formulation parameters is generated.
To Production; Scale-up
Using conventional methods, scale-up is a problem. Heating, cooling and mixing all change dramatically from a small beaker in the lab to a giant steam-jacketed kettle in production. Most companies have pilot plants to study the effect of larger equipment on the final product, a time-consuming and costly process. If formulation is undertaken with new tools—specifically, for emulsification—scale-up is no longer an issue. Using microchannel technology, the mixing process becomes an inherent component of formulation, equal in importance to the choice of emulsifiers. This approach was described in a recent article by Grace and Plonsker in GCI sister publication Cosmetics & Toiletries magazine.5
In the simplest configuration, two phases are pumped in. The external phase, usually water, flows through a channel, and the dispersed phase, usually oil, are pushed through a porous screen—which creates a steady stream of uniform small particles. The screen can be customized for different particle sizes, and the rate of flow can be controlled to create different product characteristics. Changing the flow and screen parameters changes the finished product, and, in this way, the device becomes an intrinsic part of the formulation.
Of course, the process is not limited to two phases—the system can handle multiple tanks and pumps—nor is the application of microchannels limited to standard emulsion systems. The most revolutionary benefit of the microchannel system may be the elimination of scale-up issues, a major concern with most formulations. The same device is used for lab work and production, and very large volumes can be pumped through with exactly the same end product that was produced from a few gallons of materials in the lab.
Cosmetic chemistry at the bench is a conservative operation.
Limitations in time, money, equipment and computer programs encourage “business as usual.” But for those adventurous enough to embrace the new paradigms of product development, the rewards will be great. Material mixtures never before considered (yielding formulations with superior performance and optimized delivery of actives) and manufactured with innovative processing equipment will guarantee the ultimate in beauty products.
Author’s note: In the time between writing this column and it going to press, Johann Wiechers tragically passed away. He carried his immense knowledge lightly and with great warmth and humanity, and he will be sorely missed both as a scientist and a person. This column is respectfully dedicated to his memory.
- S Herman, Chemical Reaction: Genomics-Advanced Tools to Combat Aging, GCI 178 6 50–51 (June 2010)
- S Herman, Chemical Reaction: Data, Data, Everywhere, GCI 178 4 68–70 (April 2010)
- JW Wiechers, Clinical Proof for Validity of the “Formulating for Efficacy” Concept: Enhanced Skin Delivery Results in Enhanced Skin Efficacy and Both Can Be Predicted,” IFSSC magazine, 1 2011
- M Grace and L Plonsker, Microchannel Processing: A Novel Approach to Making Emulsions, Cosmet Toiletries, 126 6 (June 2011)
Steve Herman is president of Diffusion LLC, a consulting company specializing in regulatory issues, intellectual property, and technology development and transfer. He is a principal in PJS Partners, offering formulation, marketing and technology solutions for the personal care and fragrance industry. He is an adjunct professor in the Fairleigh Dickinson University Masters in Cosmetic Science program and is a Fellow in the Society of Cosmetic Chemists.