National Allergy Research Centre, Department of Dermato-Allergology, Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark.
Int J Cosmet Sci. 2011 Apr;33(2):190-6. doi: 10.1111/j.1468-2494.2010.00619.x. Epub 2011 Jan 27.
Preservation using combinations of preservatives has several advantages. This study shows that the concentration of some of the most frequently used allergenic preservatives can be markedly lowered when they are combined with phenoxyethanol. The antimicrobial efficacy of cosmetic preservatives and known allergens of various potency [diazolidinyl urea, methylchloroisothiazolinone/methylisothiazolinone (MCI/MI), methylisothiazolinone (MI) and phenoxyethanol] was tested alone and in various combinations of two or three preservatives together. The preservatives were tested for minimum inhibitory concentration (MIC) values and possible synergy using fractional inhibitory concentration. MCI/MI was the only preservative showing low-level MIC against all four tested microorganisms: Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and Aspergillus niger. Different combinations of the preservatives indicated additive effects against the microorganisms. No combination of preservatives showed any inhibitory action on each other. Challenge tests with different concentrations and combinations were performed in a cosmetic cream. Diazolidinyl urea and MCI/MI alone were ineffective against C. albicans in a challenge test at concentrations up to 16 times higher than the observed MIC values. When combining phenoxyethanol with either one of the allergenic preservatives diazolidinyl urea, MCI/MI or MI, the cosmetic cream was adequately preserved at concentrations well below the preservatives' MIC values as well as 10-20 times below the maximum permitted concentrations. By using combinations of preservatives, effective preservation can be achieved with lower concentrations of allergenic preservatives.
采用防腐剂组合进行保存具有多个优势。本研究表明，当与苯氧乙醇结合使用时，一些最常使用的变应原性防腐剂的浓度可以显著降低。单独测试了各种效力的化妆品防腐剂和已知过敏原（重氮烷基脲、甲基氯异噻唑啉酮/甲基异噻唑啉酮（MCI/MI）、甲基异噻唑啉酮（MI）和苯氧乙醇）以及两种或三种防腐剂的各种组合的抗菌功效。使用部分抑菌浓度（FIC）测试了防腐剂的最低抑菌浓度（MIC）值和可能的协同作用。MCI/MI 是唯一对所有四种测试微生物（金黄色葡萄球菌、铜绿假单胞菌、白色念珠菌和黑曲霉）显示出低 MIC 值的防腐剂。防腐剂的不同组合对微生物表现出相加作用。没有任何防腐剂组合对彼此显示出抑制作用。在一种化妆品霜中进行了不同浓度和组合的挑战性测试。在浓度高达观察到的 MIC 值 16 倍的情况下，单独使用重氮烷基脲和 MCI/MI 对白色念珠菌的挑战测试无效。当将苯氧乙醇与变应原性防腐剂中的任一种（重氮烷基脲、MCI/MI 或 MI）结合使用时，化妆品霜可以在远低于防腐剂 MIC 值以及低于最高允许浓度 10-20 倍的浓度下得到充分保存。通过使用防腐剂组合，可以用较低浓度的变应原性防腐剂实现有效保存。
