Pm. Zavos et al., COMPARATIVE SPERMICIDAL PERFORMANCE OF IODINATED AND NON-IODINATED CONTRACEPTIVE FORMULATIONS OF NONOXYNOL-9 CO-PRECIPITATED WITH POLYVINYLPYRROLIDONE, Contraception, 54(1), 1996, pp. 39-41
The objective of this study was to evaluate the spermicidal qualities
of various combinations of nonoxynol-9 (N-9; whole molecule = oligomer
s 1-18) and its isolated fractions (oligomers 8-20, 4-6 and 1-3), co-p
recipitated with non-iodinated and/or iodinated (I-o) polyvinylpyrroli
done (PVP) as possible vaginal contraceptives. Spermicidal qualities o
f known equimolar concentrations of various combinations of PVP/N-9 an
d PVP-I-o/N-9 were tested via a modified Sander-Cramer test (SCT) usin
g human spermatozoa. Spermicidal agents and semen samples were mixed 1
:1 (v/v) and evaluated for sperm viability. Spermicidal activity was r
eported as the minimal concentration (mu g/mL) of spermicide capable o
f killing all spermatozoa within 20 sec after exposure to the spermici
de. The spermicidal activity of PVP/N-9 and PVP-I-o/N-9 preparations c
ontaining N-9 oligomers 1-18 and/or 8-10 was similar, and these prepar
ations were more efficient in killing the spermatozoa than the ones co
ntaining N-9 oligomers 4-6 and 1-3. Polyvinylpyrrolidone proved to be
an effective vehicle for PVP/N-9 and PVP-I-o/N-9 preparations, especia
lly those containing N-9 oligomers 4-6 and 1-3. Incorporation of I-o i
nto the spermicidal preparations brought about additional efficacy. Th
e current findings could be of clinical significance in future studies
when preparing and delivering those selected co-precipitates vaginall
y.