292 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS new advertising claims and new forms of product application and presenta- tion are explored. THE NEW TREND The first temporary colors were a simple mixture of acid and dye, pre- sented in an acetate capsule whose contents were to be dissolved in a cup of warm water. This solution was then poured through the hair until most of the dye was absorbed. Millions of these capsules are still sold yearly, for five to twenty-five cents each. But just as the field of hair grooming pro- gressed from the simple lemon or vinegar rinse to the currently popular cationic creme rinse, hair coloring also had to follow the new imperatives created by advertising. Thus "color conditioners" and "color creme rinses" were born. It was inevitable. Let us examine the general sales trend first before deciding how to for- mulate for it. The trend is more toward home application rather than the professional job done in the salon. This often means a lack of expertness-- lack of understanding of what can go wrong and why, lack of patience so necessary to achieve even results, and most obvious of all--.the inability of the customer to see the back of her own head. As a result, we see a profusion of new forms of applicators ranging from hollow combs with the dye solution in a "squeeze bottle" handle reservoir to aerosol colored films and foams. All stress the ease of application for the do-it-yourself fan at home. Many stress the ease of removal of the product as well. This brings us to another important part of the do-it-yourself product presentation. It is the hidden assertion by the manufacturer, and often the frank admission by his customer, that she just cannot apply the stuff prop- erly by herself, that she may want to remove it "when she tires of the shade." This is often a polite euphemism for saying, "if she didn't apply it correctly." Finally, and especially in the less urban areas, there is still perhaps the impression that dyed hair is unnatural hair and that unnatural hair is damaged hair. Under such circumstances, a co/or conditioner would be ex- pected to sell better than a hair dye. It does. As a matter of fact, it would be difficult to find any product simply labeled "hair dye" being sold today, regardless of its function. As competition grew more intense in this very lucrative, high turnover field, it was inevitable that the woman should be promised more and more. From all these claims and counterclaims and various applicators, we can be- gin to build up what is presumably the ideal product for home use. As distilled from the experience of many in the field. it would seem to be the oeu//-intensity rinse--a product giving as much color as any permanent dye,

HAIR COLORING--MODERN FORMULATION CONSIDERATIONS 293 but removable at will with a simple shampoo instead of tedious and damag- ing stripping or bleaching operations. Such a product should not rub off wet or dry and should not bleed when subjected to rain, swimming or per- spiration. It should be safe and simple to use. It should not be affected by other hair products. It should not react differently to damaged hair than to relatively normal hair. In other words, it should improve on the traditional concept of the hair dye by being relatively foolproof and there- fore proof against nuisance lawsuits. It must have these qualities to balance the fact that it suffers from its main attraction: not only may it be removed at will with a simple shampoo, but it will a/ways come off with a simple shampoo and therefore must be re- applied constantly. Nevertheless, such products seem inevitable in prod- uct planning for the near future and the formulator must therefore be pre- pared to produce them as near to the perfect ideal as possible. SURFACTANTS AND "CONDITIONERS" The formulator who wishes to improve on the standard capsule rinse con- taining 1 per cent dye plus 99 per cent citric acid normally starts with the idea of adding some sort of hair conditioner. His product at pH 2 seems to work very well in giving the small amounts of color desired. If he uses strictly nonionic conditioners such as the lanolin derivatives and other "superfarting" agents, he will not get into too much trouble except for the problem of emulsifying at such a low pH. Occasionally, these materials may interfere with the action of his dyes by adsorbing onto the hair before the dye solution can make really good contact. An example is mineral oil, often added to formulation to give "combability" by making the hair more slippery during the application. Another was patented by Beste (1) who found that certain alkylphenoxyethanol nonionic surfactants could be used in the dual function of emollient and dye rate controller, since they prefer- entially sorb onto the hair and present a barrier to the dyes. Due to its amphoteric nature, keratin will also tend to sorb both anionic and cationic materials to varying degrees depending on their polarity. This results in a "conditioning action" if the materials happen to be some- what fatty or oily. They leave the hz. ir lustrous, which means "healthy" by current advertising definition. Today's color creme rinse formulations often contain dyes complexed with fatty materials to give such a look to the hair. These adsorbed layers generally conduct electricity well also and thus impart antistatic properties to the hair so that it stays rather liraply in place when combed. The total effect of these products is often described incorrectly as softening the hair, a much maligned verb now equated to con- ditioning, even though damaged hair is weak and soft while normal hair is firm and hard. Putting a fatty sheath on the hair may make it look lus- trous and feel silky, but anyone who sells substantive hair dyes can attest 1o