ASSESSMENT OF A TABLET DRUG-DELIVERY SYSTEM INCORPORATING NONOXYNOL-9COPRECIPITATED WITH POLYVINYLPYRROLIDONE IN PREVENTING THE ONSET OF PREGNANCY IN RABBITS
Pm. Zavos et al., ASSESSMENT OF A TABLET DRUG-DELIVERY SYSTEM INCORPORATING NONOXYNOL-9COPRECIPITATED WITH POLYVINYLPYRROLIDONE IN PREVENTING THE ONSET OF PREGNANCY IN RABBITS, Fertility and sterility, 69(4), 1998, pp. 768-773
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 a
bility to prevent the onset of pregnancy in rabbits. Design: Controlle
d clinical study. Setting: Division of Laboratory and Animal Resources
, College of Pharmacy, University of Kentucky. Animal(s): Forty-two Ne
w Zealand White female rabbits. Intervention(s): The rabbits were arti
ficially inseminated at various intervals after vaginal insertion of t
he tablet drug delivery system containing either polyvinylpyrrolidone
only (0 minutes) or nonoxynol-9 coprecipitated with polyvinylpyrrolido
ne (polyvinylpyrrolidone/nonoxynol-9; 0, 3, 30, 180, and 360 minutes).
The rabbits were induced to ovulate 6 hours before insemination by IM
injection of hCG (200 IU). Main Outcome Measure(s): The onset of preg
nancy in the rabbits was evaluated after insertion of the tablet drug
delivery system containing polyvinylpyrrolidone only or polyvinylpyrro
lidone/nonoxynol-9 at various intervals, followed by artificial insemi
nation. Result(s): The onset of pregnancy was not reduced significantl
y when the tablet drug delivery system containing polyvinylpyrrolidone
or polyvinylpyrrolidone/nonoxynol-9 was used and insemination was per
formed immediately after tablet insertion (time 0). However, pregnancy
rates (PRs) were reduced significantly in the rabbits that received t
he tablet drug delivery system containing polyvinylpyrrolidone/nonoxyn
ol-9 and were inseminated at 3, 30, 180, and 360 minutes after tablet
insertion. The highest PR reduction occurred between 30 and 180 minute
s after insertion of the tablet drug delivery system containing polyvi
nylpyrrolidone/nonoxynol-9. Conclusion(s): The tablet drug delivery sy
stem is an efficient method of delivering the tested spermicidal agent
s vaginally. The design and dosage used in preparing the tablet drug d
elivery system provide short-and long-term release of the spermicidal
agents, which results in almost immediate and extended enhancement of
their contraceptive properties. (C) 1998 by American Society for Repro
ductive Medicine.).