Correlation of Cytotoxicity and Antimicrobial Activity of Alkandiols and Their Impact on Stability in Emulsions

Abstract

Purpose: This study aimed to contribute to the development of various cosmetic formulations by adding alkanediols of ethyl hexanediol, methylpropanediol, 2-butyl-2-ethyl-1,3-propanediol, and ethylhexylglycerin (mainly 1,2-octanediol and 1,2-hexanediol) to emulsion formulations to determine their emulsion phase stability as well as their preservation against microbial contamination.Methods: The alkanediols were added to the emulsions to assess their preservation effects and phase stability under various storage temperatures for 3 months. In addition, their fibroblast cytotoxicity and anti-bacterial activity against microorganisms were compared.Results: A greater preservation effect was observed with longer linear alkanediol alkyl carbon chain lengths. However, higher formulation content revealed instability in phase stability. Furthermore, evaluation of fibroblast cytotoxicity showed that the relationship between cell membrane disruption and antimicrobial activity was affected.Conclusion: Utilizing the correlation between cytotoxicity and antimicrobial activity because of the carbon number and diol chemical structure, these results are expected to contribute to the development of improved preservative boosters that provide synergistic effects in terms of antimicrobial activity against microbial contamination, human safety, and the phase stability of formulations in the future.