University of Hertfordshire

  • E. Cooper
  • A. Iqbal
  • A. Bartlett
  • C. Marriott
  • P.J. Whitfield
  • Marc Brown
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Original languageEnglish
Number of pages6
Pages (from-to)957-962
JournalJournal of Pharmacy and Pharmacology
Journal publication dateAug 2004
Publication statusPublished - Aug 2004


Recently, a dimeticone formulation has been shown to be effective at preventing Schistosoma cercariae infecting skin, while DEET (N,N-diethyl-m-toluamide), a highly effective insecticide, has been shown to have activity against cercariae. Seven formulations, 3 containing DEET, were prepared and applied to excised human skin in Franz cells for 1 h. Schistosoma cercariae were applied for 30 min at 1 and 24 h, and the number that penetrated the skin calculated (n = 9). DEET could not be incorporated into the dimeticone formulation, yet it remained the most effective at preventing cercarial penetration, both 1 and 24 h after application. The ointments that contained DEET did prevent penetration but their mode of action was due to the toxicity of DEET against the cercariae. The persistence of the protection afforded by the dimeticone formulation after washing suggests that the formulation may be interacting with the stratum corneum to prevent cercarial recognition of skin.

ID: 628631