In this study, we developed make-up remover preparations comprising a bicontinuous microemulsion using polyglycerol fatty acid esters (PGFE). We obtained the microemulsion by mixing PGFEs with different HLB (hydrophile-lipophile balance) values, then replaced part of the water with polyol and adjusted the relative HLB of the system. Comparison of the phase diagrams of the PGFE and polyoxyethylene (POE)-type nonionic surfactant in the oil and water showed that PGFE formed an I-phase region in a wide temperature range even at low concentrations. This indicated that the HLB of PGFE was not susceptible to the effect of temperature, unlike that of a POE-type nonionic surfactant. In the actual test, the features of the preparations using the bicontinuous microemulsion were evaluated. Taking into consideration that make-up removers are used even around the eyes, we performed an eye irritation test and obtained results indicating that safety was high. Thus, by using PGFE, we obtained a microemulsion with little temperature dependence even at low concentrations of the surfactant and were able to develop preparations that combined high functionality, usability, and safety.
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