In the face of spreading concerns about the safety of the antidandruff agent coal tar, personal care formulators are seeking a safe substitute with equivalent effi cacy. One alternative is sodium shale oil sulfonate, a proprietary ingredient that is used in antidandruff shampoos in Europe but is not presently approved for use in the United States as an antidandruff agent. This article describes the fi rst ever comparison test of these two ingredients on the basis of their effi cacy in treating dandruff and two of its concomitant symptoms, which are skin redness and itching.
Antidandruff activity: Coal tar (CT) has been used in the treatment of dandruff for many years because of its broad action profile, which includes anti-mitotic, anti-microbial, anti-seborrhoic as well as keratolytic, anti-itching and anti-inflammatory actions.
In dandruff (dry and greasy forms), all the characteristics mentioned in Table 1 are interconnected in such a way that dandruff is referred to as a vicious cycle of excessive desquamation. Active ingredients with a broad action profile obviously offer different starting points and approaches to treat this problem. Safety: Although the regulatory status of CT in the United States allows its application in OTC products for dandruff treatment, there is ongoing discussion regarding its tolerance and safety. Because CT is a thick liquid or semi-solid obtained in the destructive distillation of coal at temperatures of about 1000°C, it is a complex mixture of thousands of compounds, many of which have been identifi ed as benzenes, xylenes, naphthalenes, cresols, phenols and polycyclic aromatic hydrocarbons (PAH). Among the PAH are found many substances that are carcinogenic. Benzo[a]pyrene is regarded as a leading substance in this respect. Dermatologically used CT contains about 0.5 to 0.7% (5000-7000 ppm) of carcinogenic benzo[a]pyrene.