Microbiological stabilization of preservative-free semisolid products
Care products for sensitive skin need careful selection of the used excipients. In order to get excellent compatibilitywith such challenging skin conditions, the use of conventional preservatives, fragrances and colouring agents as well asethoxylated emulsifiers and mineral oils should be omitted. Modified glycols having emollient and humectant properties wereused for the microbiological stabilization of cosmetic w/o and o/w systems. Their influence on the physical stability of suchpreparations and their antimicrobial efficacy was investigated. Based on their solubility properties, a mixture of caprylyl glycoland ethylhexylglycerin was found to be a suitable antimicrobial agent for o/w-preparations. In combination with a low wateractivity and a low ph value, this alternative preservation system also ensures a satisfying microbial stability in w/o-preparations.