As formulators we are told that “oil and water don’t mix” and “anionic and cationic compounds are incompatible”. While these broad statements are generally helpful, they should neither be taken as absolute truth or limit creativity in formulation research. We know that oil and water can mix, if the proper emulsifier is added and the right homogenization process is followed. As for the incompatibility of anionic and cationic compounds, this rule is not absolute. Properly chosen cationic and anionic surfactants when combined will not only produce clear systems, but systems that have good foam and good substantivity to hair.
Use general rules as guidelines, none are aboslute truths.
It is always amazing that cosmetic formulators can put together very sophisticated products that contain many different raw materials. These materials all interact with each other sometimes in unpredictable ways. The interactions that occurs when combining the raw materials used in the formulation of personal care products is more than the sum of the properties of each of the raw materials.
There are a number of complex interactions that occur in the most simple formulation. These interactions can either enhance or detract from the functional attributes of the formulation.
Since most of today's high performance formulations are very complex containing a pleth