Pm. Zavos et al., ASSESSMENT OF NEW FORMULATIONS OF NONOXYNOL-9 COPRECIPITATED WITH POLYVINYLPYRROLIDONE AND IODINE AS POSSIBLE VAGINAL CONTRACEPTIVES, Fertility and sterility, 66(5), 1996, pp. 729-733
Objective: To assess the in vitro spermicidal activity of new formulat
ions of nonoxynol-9, coprecipitated with polyvinylpyrrolidone (PVP) or
iodinated PVP, against human spermatozoa via the use of the Sander-Cr
amer test and the cervical mucus penetration test. Design: Solutions o
f PVP-nonoxynol-9 and iodinated PVP-nonoxynol-9 containing nonoxynol-9
whole molecule (oligomers 1 to 18) and its isolated fractions (oligom
ers 8 to 10, 4 to 6, and 1 to 3) at various concentrations (mu g/mL) w
ere prepared via serial dilutions. Spermicidal solutions were mixed wi
th human semen to determine the minimal lethal dose (mu g/mL). In the
Sander-Cramer test, the lethal dose was reported as the minimal dose c
apable of killing spermatozoa within 20 seconds. In the cervical mucus
penetration test, the lethal dose was reported as the minimal dose ca
pable of preventing penetration of spermatozoa into cervical mucus bey
ond the second millimeter length of the capillary. Setting: Andrology
laboratory, University of Kentucky, Lexington, Kentucky. Patient(s): N
ormospermic male donors. Main Outcome Measure(s): Spermicidal lethal d
ose determination of various nonoxynol-9 preparations containing the w
hole nonoxynol-9 molecule and its isolated fractions coprecipitated wi
th PVP or iodinated PVP. Result(s): The use of PVP increased the aqueo
us solubility of the nonoxynol-9 formulations containing oligomers 1 t
o 18 and 8 to 10 slightly. The coprecipitation of the nonoxynol-9 form
ulations containing nonoxynol-9 oligomers 4 to 6 and 1 to 3 with PVP s
ignificantly increased their solubilization and spermicidal action in
vitro. Moreover, the incorporation of iodine significantly decreased t
he minimal nonoxynol-9 dose required for complete killing of spermatoz
oa in preparations containing nonoxynol-9 oligomers 4 to 6 and 1 to 3.
Conclusion(s): Incorporation of all three components tested in this s
tudy (PVP, nonoxynol-9, and iodine) enhanced the efficiency of the spe
rmicidal preparations, especially for nonoxynol-9 preparations contain
ing nonoxynol-9 oligomers 4 to 6 and 1 to 3.