title: Assessment of a tablet drug delivery system incorporating nonoxynol-9 coprecipitated with polyvinylpyrrolidone in preventing the onset of pregnancy in rabbits.
abstract: OBJECTIVE
  To assess the in vivo efficacy of the tablet drug delivery system containing nonoxynol-9 coprecipitated with polyvinylpyrrolidone by delivering the spermicidal agents vaginally and evaluating their ability to prevent the onset of pregnancy in rabbits.
  
  
  METHODS
  Controlled clinical study.
  
  
  METHODS
  Division of Laboratory and Animal Resources, College of Pharmacy, University of Kentucky.
  
  
  METHODS
  Forty-two New Zealand White female rabbits.
  
  
  METHODS
  The rabbits were artificially inseminated at various intervals after vaginal insertion of the tablet drug delivery system containing either polyvinylpyrrolidone only (0 minutes) or nonoxynol-9 coprecipitated with polyvinylpyrrolidone (polyvinylpyrrolidone/nonoxynol-9; 0, 3, 30, 180, and 360 minutes). The rabbits were induced to ovulate 6 hours before insemination by i.m. injection of hCG (200 IU).
  
  
  METHODS
  The onset of pregnancy in the rabbits was evaluated after insertion of the tablet drug delivery system containing polyvinylpyrrolidone only or polyvinylpyrrolidone/nonoxynol-9 at various intervals, followed by artificial insemination.
  
  
  RESULTS
  The onset of pregnancy was not reduced significantly when the tablet drug delivery system containing polyvinylpyrrolidone or polyvinylpyrrolidone/nonoxynol-9 was used and insemination was performed immediately after tablet insertion (time 0). However, pregnancy rates (PRs) were reduced significantly in the rabbits that received the tablet drug delivery system containing polyvinylpyrrolidone/nonoxynol-9 and were inseminated at 3, 30, 180, and 360 minutes after tablet insertion. The highest PR reduction occurred between 30 and 180 minutes after insertion of the tablet drug delivery system containing polyvinylpyrrolidone/nonoxynol-9.
  
  
  CONCLUSIONS
  The tablet drug delivery system is an efficient method of delivering the tested spermicidal agents vaginally. The design and dosage used in preparing the tablet drug delivery system provide short- and long-term release of the spermicidal agents, which results in almost immediate and extended enhancement of their contraceptive properties.
authors.affiliation: Department of Animal Sciences, University of Kentucky, Lexington, USA.
authors.forename: P M
authors.initials: PM
authors.lastname: Zavos
authors.forename: J R
authors.initials: JR
authors.lastname: Correa
authors.forename: P N
authors.initials: PN
authors.lastname: Zarmakoupis-Zavos
mesh_terms: D000282:Administration, Intravaginal; D000818:Animals; D011232:Chemical Precipitation; D015331:Cohort Studies; D004338:Drug Combinations; D016503:Drug Delivery Systems; D005260:Female; D007315:Insemination, Artificial; D008297:Male; D017137:Nonoxynol / Q000008:administration & dosage* / Q000494:pharmacology; D010592:Pharmaceutic Aids / Q000008:administration & dosage* / Q000494:pharmacology; D011205:Povidone / Q000008:administration & dosage* / Q000494:pharmacology; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D011817:Rabbits; D013081:Sperm Motility / Q000187:drug effects / Q000502:physiology; D013089:Spermatocidal Agents / Q000008:administration & dosage* / Q000494:pharmacology; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology; D013607:Tablets; D013997:Time Factors
chemical_list: D004338:Drug Combinations; D010592:Pharmaceutic Aids; D013089:Spermatocidal Agents; D013607:Tablets; D017137:Nonoxynol; D011205:Povidone