A phase I comparative study of three contraceptive vaginal films containing nonoxynol-9: Postcoital testing and colposcopy

Abstract

The objectives of this study were 1) to assess the ability of a new contraceptive vaginal film containing two doses of nonoxynol-9 (N-9) to prevent the penetration of sperm into midcycle cervical mucus, and 2) to determine the effect of the film on the vaginal epithelium. The novel formulation was compared with VCF ® (a currently marketed film also containing N-9). Ten women underwent two baseline cycles of postcoital testing in which no film was used, followed by three test cycles in which Allendale-N9 film, a new film containing either 100 or 130 mg N-9, or VCF containing 70 mg N-9 was used. The sequence of testing cycles was randomized. In each cycle, condoms were used prior to midcyle, then a midcycle cervical mucus specimen was examined to ensure midcycle characteristics and the absence of sperm. Each woman then had intercourse using either no film (baseline cycles) or a test film (test cycles) and returned 2–3 h afterwards. Cervical mucus was again assessed for adequacy and the presence of sperm. Each woman also underwent colposcopy using a protocol developed by the World Health Organization. The average number of progressively motile sperm seen per high power field were as follows: average of the two baseline cycles, 19.3; test cycle with Allendale-N9 film containing 100 mg N-9, 0.6; test cycle with Allendale-N9 film containing 130 mg N-9, 0.9; and test cycle with VCF 0.6. There was no significant difference between baseline cycles or between test cycles in the number of progressively motile sperm per high power field (HPF) seen (p = 0.31 and p ≥ 0.50, respectively). The average number of motile sperm seen in each test cycle did, however, differ significantly from the number in either baseline cycle (p < 0.02). The majority of colposcopic examinations were normal. In one baseline cycle and eight test cycles, colposcopy showed superficial de-epithelialization without underlying inflammation. There was no apparent dose response and in all cases the volunteers were asymptomatic. A vaginal contraceptive containing either 100 or 130 mg N-9 in a new film base appears to be safe and comparable to VCF in preventing sperm from entering midcycle cervical mucus.