Influence of Polysorbate on the Activity of Some Antimicrobial Preservatives

Thumbnail Image
Journal Title
Journal ISSN
Volume Title
The antimicrobial activity of Chlorocresol and salicylic acid against E. coli, Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus were studied in the presence of Polysorbate. Polysorbate is a surfactant and it prevents coalescence by reducing interfacial tension of immiscible liquids. The activities of Chlorocresol and salicylic acid were considerably inhibited by the Polysorbate. The interactions of the antimicrobial with the Polysorbate and subsequent reduction in the availability of the preservatives to the bacterial cells were found to be the predominant mechanism in the reduction of the activities of the preservatives. Physical shielding of the bacterial cells from the actions of the preservatives was the primary cause for the lower activities of the preservatives in the presence of the Polysorbate. The physical influence of Polysorbate on the preservatives was also determined using the UV spectrophotometer. The reduction in the Spectrophotometric activity of the preservatives in the presence of Polysorbate was found to be caused by the physical binding of the Polysorbate to part of the active surfaces of the preservatives.
A Thesis submitted to the School of Graduate Studies, Kwame Nkrumah University of Science and Technology, Kumasi, in partial fulfilment of the requirements for the Degree of Master of Philosophy in Pharmaceutical Microbiology, August-2010