Low potential ocular irritation of arginine-based gemini surfactants and their mixtures with nonionic and zwitterionic surfactants

Purpose. The aim of this study was to find new biocompatible surfactants and mixtures with low ocular irritant action for application in pharmaceutical formulations and to establish a relationship between their structure and their potential ocular irritant activity. Methods. An alternative method to the Draize in vivo test, based on the adverse effects of surfactants on the cytoplasmic membrane of red blood cell, was used to evaluate the potential ocular irritation of the surfactants. Results. It was found that the hemolytic activity of arginine-based gemini surfactants increased with the aliphatic alkyl chain lengths of the hydrophobic tail. The addition of the surfactant with an alkyl chain length of 10 carbon atoms to cocoamidopropilbetaina (TB), decylglucoside (APG), and N-alpha-lauroyl-arginine ethyl ester (LAE) increases the hemolytic activity moderately for the mixtures with TB and LAE (1.1- and 1.5-fold, respectively) and strongly for APG (five-fold). Conclusions. The new arginine-based gemini surfactants constitute a suitable alternative to commercial surfactants because of their natural origins, which make them biocompatible and renewable products. Based on their hemolytic activity as an alternative to the Draize test, these new arginine-based gemini surfactants and their mixtures can be classified as mild irritants. This fact constitutes an advantage, especially for pharmaceutical and cosmetic applications.