Distribution of a vaginal gel (Invisible Condom) before, during and after simulated sexual intercourse and its persistence when delivered by two different vaginal applicators: a magnetic resonance imaging study

Contraception. 2008 Jun;77(6):447-55. doi: 10.1016/j.contraception.2008.01.015. Epub 2008 Apr 18.


Objective: The objective of this study was to evaluate the vaginal distribution of a microbicidal gel (Invisible Condom) before, during and after simulated intercourse using an artificial phallus. The gel was delivered using either a new proprietary vaginal applicator (PVA), which has multiple lateral and apical holes, or a commercial applicator (CA), which has a single apical hole. The persistence of the gel was evaluated up to 24 h after its administration.

Study design: Nine women (five women using the PVA and four women using the CA) applied the vaginal gel once, and pelvic images were taken immediately after application. An artificial phallus was inserted and the women had 30 vaginal thrusts, then another set of images was taken while the phallus was still inside the vagina. On exit of the phallus, one more set of images was taken. Images were subsequently taken at 30 min, 2 h, 6 h and 24 h after gel application.

Results: Immediately after gel application, the PVA distributed the gel throughout the vaginal/cervical mucosae, while the CA delivered the gel only to the cervical area. During simulated intercourse, the phallus further pushed the gel delivered with the CA into the fornix, whereas it spread the gel delivered with the PVA more evenly throughout the mucosal surface. After simulated intercourse, both applicators gave similar gel distributions between 30 min and 6 h after application. However, at 24 h, using the PVA, only 5% of the gel persisted in the vagina, compared to 40% of the gel using the CA.

Discussion and conclusion: Using the new PVA, the Invisible Condom covered the vaginal/cervical mucosae before and during simulated intercourse, offering immediate protection, whereas only the cervical mucosa was covered using the CA. Forty percent of the gel persisted mostly in the upper vaginal/cervical area at 24 h following its administration with the CA, while only 5% of the gel was left using the PVA. The new applicator, with its unique design, ensures an even and immediate coating lasting throughout the first 6 h and could prevent potential microbicide vaginal toxicity at 24 h.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Intravaginal
  • Anti-Infective Agents / administration & dosage
  • Anti-Infective Agents / pharmacokinetics
  • Cervix Uteri / metabolism
  • Coitus / physiology
  • Drug Delivery Systems*
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Sodium Dodecyl Sulfate / administration & dosage*
  • Sodium Dodecyl Sulfate / pharmacokinetics*
  • Spermatocidal Agents / administration & dosage*
  • Spermatocidal Agents / pharmacokinetics*
  • Tissue Distribution
  • Vagina / metabolism*
  • Vaginal Creams, Foams, and Jellies / administration & dosage
  • Vaginal Creams, Foams, and Jellies / pharmacokinetics


  • Anti-Infective Agents
  • Spermatocidal Agents
  • Vaginal Creams, Foams, and Jellies
  • Sodium Dodecyl Sulfate