The Antimicrobial Activity of Oil-in-Water Microemulsions is predicted by their position within the Microemulsion Stability Zone


  • Ibrahim Al-Adham School of Pharmacy & Medical Technology University of Petra Amman
  • Ali Al-Nawajeh School of Contemporary Sciences University of Abertay Dundee Dundee DD1 1HG
  • Enam Khalil School of Pharmacy University of Jordan Amman
  • Phillip Collier School of Contemporary Sciences University of Abertay Dundee Dundee DD1 1HG


microemulsion, antimicrobial activity, stability zone, biocide, Pseudomonas aeruginosa


It has been shown previously that thermodynamically stable oil-in-water microemulsions have significant antimicrobial activity against planktonic cells and biofilm cells over short periods of exposure. It was the aim of this study to identify whether the position of the microemulsion within the microemulsion stability zone of the pseudo-ternary phase structure predicts the efficiency of the antimicrobial action of the microemulsion. Microemulsions were formulated at different points within the microemulsion stability zone. Experiments were performed to observe the kinetics of killing of these microemulsions against selected test microorganisms (Pseudomonas aeruginosa ATCC 9027, Candida albicans ATCC 10231, Staphylococcus aureus ATCC 6538 and Aspergillus niger ATCC 16404). The results indicated that the antimicrobial activity of the microemulsion is dependant upon its position within the zone of stability and is greater nearer the centre of that zone. The results indicate that significant antimicrobial activity can be observed at all points within the zone of microemulsion stability, but that maximal activity is to be found at the centre of that area.

Author Biography

Phillip Collier, School of Contemporary Sciences University of Abertay Dundee Dundee DD1 1HG

Director of Research Degrees

Senior Lecturer in Microbiology


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