OLEIC ACID/GLYCOL: AN ALTERNATIVE TO PENTANOL IN MICROEMULSIONS WITH ANIONIC SURFACTANT

New possibilities on the substitution of pentanol as cosurfactant on the preparation of microemulsions with anionic surfactants, are suggested. Alternative systems with more skin compatible ingredients as are oleic acid and glycols, allows to obtain microemulsions of potential application in fields as are the cosmetic and dermopharmaceutical ones, in which the requirements of harmlessness of the ingredients reduces the possibility of application of the conventional microemulsions with pentanol. The capacities of solubilizing hydrocarbon, were stated depending on the chain lenght of the glycol as well as on the ratio of combination water/glycol. The possibilities of the different systems were evidenced by means of the corresponding phase diagrams, resulting that the shorter the hydrocarbon chain lenght of the glycol is (ethyleneglycol), the wider is the realm of microemulsion obtained, and being established an optimal ratio water/glycol around 1/1. Moreover, the system with oleic acid and ethyleneglycol allows to prepare easily both W/O and O/W microemulsions, overcoming the possibilities of the classical system with pentanol.