title: Spermicidal and antifertility effects of an imbibing and soluble nonoxynol-9 diaphragm (ISND) in rabbits.
abstract: OBJECTIVE
  To determine the minimum effective concentration (MEC) of an imbibing and soluble nonoxynol-9 (N-9) diaphragm (ISND) required for immobilisation of all spermatozoa in vitro and in vivo. The speed of semen absorbance, time of ISND to dissolution, and the antifertility effects were also investigated in rabbits.
  
  
  METHODS
  In vitro spermicidal tests with ISND were conducted using fresh semen from humans and rabbits. Spermicidal and antifertility effects were observed in vivo after the ISND was placed directly into the vagina of rabbits.
  
  
  RESULTS
  The MEC of N-9 required in the ISND to totally immobilise sperm within 20 seconds was 0.15 mg/ml for human sperm, and 0.5 mg/ml for rabbit sperm. The human semen was absorbed into the ISND in 45 minutes; the diaphragm dissolved in the vagina 3.5 hours later. In vivo, in rabbits, the MEC of N-9 required to immobilise sperm within five minutes of mating was 1 mg/kg in the ISND, and 10 mg/kg for the nonoxynol-9 film. The median effective dose of N-9 in the ISND was 1.07 mg/kg, whereas for the film it was 3.30 mg/kg.
  
  
  CONCLUSIONS
  The spermicidal and antifertility activities of a low dose N-9 in the ISND were high, with properties of imbibition and solubility confirmed.
authors.affiliation: Central Laboratory of Hebei Research Institute for Family Planning , Shijiazhuang, Hebei Province , China.
authors.forename: Li
authors.initials: L
authors.lastname: Rongxiu
authors.forename: Li
authors.initials: L
authors.lastname: Guozheng
authors.forename: Liu
authors.initials: L
authors.lastname: Xiaoqun
authors.forename: Tian
authors.initials: T
authors.lastname: Huiyan
mesh_terms: D000818:Animals; D003274:Contraceptive Devices, Female; D005260:Female; D006801:Humans; D008297:Male; D017137:Nonoxynol / Q000008:administration & dosage* / Q000494:pharmacology; D011817:Rabbits; D012661:Semen; D013081:Sperm Motility / Q000187:drug effects; D013089:Spermatocidal Agents / Q000008:administration & dosage* / Q000494:pharmacology; D013094:Spermatozoa / Q000187:drug effects
chemical_list: D013089:Spermatocidal Agents; D017137:Nonoxynol
keywords: Antifertility; Diaphragm; ISND; Nonoxynol-9; Rabbit; Spermicide