Heterogeneous Systems II: Influence of Partitioning and Molecular Interactions on in vitro BiologicActivity of Preservatives in Emulsions

Patel, Nagin K.; Romanowski, Joyce M.

doi:10.1002/jps.2600590321

Cited by 16 publications

(3 citation statements)

References 10 publications

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“…7 A) . Similar results were reported for other microorganisms in paraben and non-ionic surfactant systems (Patel and Romanowski, 1970;Shimamoto et al, 1973;Yamaguchi et al, 1982) . BP incorporated into the cells in the antibacterial test solution was undetectable because of the negligible volume of the cells (10-5 ml/ml), compared with the cell volume in BP uptake test solutions (0.0125 to 0 .10 ml/ml) .…”

Section: Comparison Of Observed and Estimated Bp Concentrations In Pcsupporting

confidence: 88%

“…Figure 7 B shows the relationship between log (No/N24) and free BP concentration in the aqueous PCE solution with a negligible volume of the E. coli cells. Although it was frequently noted that a decrease in free parabens in preparations including non-ionic surfactants resulted in the increase in the paraben concentration required to sterilize (Patel and Romanowski, 1970;Shimamoto et al, 1973;Yamaguchi et al, 1982), the antibacterial activity of BP was found to be highly proportional to free BP concentration in the aqueous phase in the presence of PCE. The BP uptake in a negligible amount of bacterial cells should thus certainly also be related to free BP concentration in an antibacterial test solution.…”

Section: Comparison Of Observed and Estimated Bp Concentrations In Pcmentioning

confidence: 99%

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Effects of Polyoxyethylene Cetyl Ether on the Cellular Uptake and Antibacterial Activity of Butyl p-Hydroxybenzoate against Escherichia coli.

et al. 1998

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The effects of polyoxyethylene cetyl ether (PCE) on the cellular uptake and the antibacterial activity of butyl p-hydroxybenzoate (BP) by bacteria were studied using an aqueous suspension of Escherichia coli. The BP in the cell suspension was distributed in the cells and aqueous phase. PCE added to the BP solution was responsible for reducing the BP uptake into the cells and inhibiting the antibacterial activity of BP due to the formation of a complex between BP and PCE micelles. The uptake and antibacterial activity of BP were proportional to the unbound BP concentration in the aqueous bulk solution. However, the addition of PCE repressed BP uptake in the cells and enhanced BP activity compared with those values expected from unbound BP in the aqueous surfactant solution. These results suggested that direct interactions between PCE and bacterial cells increased the susceptibility of bacteria. The decrease in BP uptake into bacterial cells was thus concluded to be responsible for the reduction in the antibacterial activity of BP in an aqueous surfactant solution, and the measurement of paraben uptake by microbial cells was found to be a reliable means for assessing inactivation in an aqueous solution in the presence of surfactants.

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Section: Comparison Of Observed and Estimated Bp Concentrations In Pcsupporting

confidence: 88%

Section: Comparison Of Observed and Estimated Bp Concentrations In Pcmentioning

confidence: 99%

Effects of Polyoxyethylene Cetyl Ether on the Cellular Uptake and Antibacterial Activity of Butyl p-Hydroxybenzoate against Escherichia coli.

et al. 1998

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“…It lias been demonstrated by Wedderburn (1964) that 1 per cent Tween 80 will bind and so inactivate 96 per cent of available concentration of some quaternary ammonium antiseptics, Further, 5 per cent Tween 80 will bind 95 • 5 per cent of added propyl parahydroxybenzoate (jjaraben), Proj^ylparaben has a greater affinity for tiiis type of complexing than metliyl paraben. Care must be taken when increasing the concentration of paraben as a counter measure because it may affect the stability of the emulsion (Patel and Romanowski 1970), The binding effect of non-ionics also extends to phenolics such as phenol, resorcinol and mentliol; acids such as benzoic, salicylic and sorbic ; organic mercurials (PMN, PMA) and chlorbutol. The effect of polyoxyetliylenes on phenolic antibacterials is thouglit to occur in two stages.…”

Section: Emulsion Basesmentioning

confidence: 99%