USE OF IN-VITRO METHODS TO RANK SURFACTANTS FOR IRRITATION POTENTIAL IN SUPPORT OF NEW PRODUCT DEVELOPMENT

11 surfactant raw materials with potential applications in light-duty liquid cleaning products were evaluated in vitro using a human skin an alogue (ATS SKIN2 Model ZK1100) for predicting cytotoxicity (MTT reduc tion) and inflammation [prostaglandin E(2) (PGE(2)) release]. Two of t he 11 raw materials, both in the same compound family, were selected t o be individually combined with each of the other nine in a 90:10 (raw :selected raw) mixture. Selection criteria were based on desired perfo rmance characteristics and low irritation potential as suggested from the individual surfactant assay data. To determine whether irritation potential was mitigated, MTT and PGE(2) scores were again determined f or each of the 18 combinations with the resulting data being compared with the untreated raw material data. A plot of the data indicated tha t one of two selected materials may have an 'anti-irritant' effect. Fo r raw materials with intrinsic MTT scores of less than 50 mu g/ml and with the original data corrected for possible dilution effects, a stat istical comparison between individual raw materials and the two sets o f combinations was done using a one-sample analysis. Both cytotoxicity (MTT) and inflammation (PGE(2)) were significantly decreased by the m ilder of the two selected raw materials. By factoring the data into fu ture new product decisions, this methodology has become a useful and p ractical tool for Amway product development.