title: Protective effect of a thermoreversible gel against the toxicity of nonoxynol-9.
abstract: OBJECTIVE
  One major problem associated with the use of nonoxynol-9 is that it can induce local inflammation and ulceration of the vaginal and cervical mucosa that might favor the entry of pathogens. With the aim of developing a gel formulation that could be effective in preventing sexually transmitted infections, the authors have evaluated the capacity of a polyoxypropylene/polyoxyethylene polymer to reduce or eliminate the toxicity of nonoxynol-9.
  
  
  METHODS
  The cytotoxicity of nonoxynol-9 alone or incorporated into the gel was investigated in human cervical and colon epithelial cells and after daily intravaginal application for 2 weeks in rabbits.
  
  
  RESULTS
  In vitro experiments showed that nonoxynol-9 was highly toxic to human cervical and colon epithelial cells in a dose-dependent manner. However, the incorporation of the spermicide into the gel markedly reduced its toxicity under the same experimental conditions. In vivo studies showed that in animals treated with nonoxynol-9, the spermicide was very toxic to the vaginal and cervical mucosa as evidenced by the presence of bleeding, irritation, epithelial disruption, necrosis, the accumulation of leukocytes in the submucosa, and the loss of integrity of the epithelial cells. Of prime importance, the incorporation of nonoxynol-9 into the gel markedly reduced the toxicity of this potent spermicide/microbicide.
  
  
  CONCLUSIONS
  The gel formulation could be used as an interesting approach to eliminate the toxicity of potent spermicides/microbicides such as nonoxynol-9.
authors: Centre de Recherche en Infectiologie, Centre Hospitalier Universitaire de Québec, Pavillon CHUL, Ste-Foy, Canada.
authors: N
authors: N
authors: Gagné
authors: H
authors: H
authors: Cormier
authors: R F
authors: RF
authors: Omar
authors: A
authors: A
authors: Désormeaux
authors: P
authors: P
authors: Gourde
authors: M J
authors: MJ
authors: Tremblay
authors: J
authors: J
authors: Juhász
authors: D
authors: D
authors: Beauchamp
authors: J E
authors: JE
authors: Rioux
authors: M G
authors: MG
authors: Bergeron
mesh_terms: D000818:Animals; D004058:Diffusion; D004347:Drug Interactions; D005260:Female; D005782:Gels; D009092:Mucous Membrane / Q000187:drug effects; D017137:Nonoxynol / Q000633:toxicity*; D011092:Polyethylene Glycols; D011108:Polymers; D011126:Polypropylenes; D020011:Protective Agents; D011817:Rabbits; D014407:Tumor Cells, Cultured
chemical_list: D005782:Gels; D011108:Polymers; D011126:Polypropylenes; D020011:Protective Agents; D017137:Nonoxynol; D011092:Polyethylene Glycols