The objective of this study was to determine the magnitude and duration of the reduction in pH (acidification) following a single dose of Acidform vaginal gel containing 3, 4, or 5 g compared with hydroxyethylcellulose placebo gel (4 g) or no treatment. Vaginal pH was measured 1 h, 6 h, 12 h, 24 h, then once daily for 7 days. In addition, the participants were assessed for an exploratory endpoint to the determine effect of one dose of Acidform gel (3, 4 or 5 g) or placebo gel (4 g) or no treatment, on asymptomatic bacterial vaginosis (BV).

One hundred healthy volunteer women, 20 per each treatment arm, were treated with either Intravaginal Acidform Gel(IVAG), 5 g dose (GROUP A), Acidform gel, 4 g dose (GROUP B), Acidform gel, 3 g dose (GROUP C), Universal Placebo Gel (UPG), 4 g (GROUP D) or no treatment (GROUP E). For GROUPS A, B, C and D, treatment is defined as speculum exam plus instillation of Investigational Product (IP) or placebo gel. For GROUP E (control), no treatment is defined as speculum exam and no gel instillation.

At least 15 women in each group were of either African American or Hispanic ethnicity. Routine screening tests were performed on admission; and subjects assessed for BV via vaginal swabs obtained for grading by Amsel criteria.

A direct vaginal pH reading by research staff- was obtained before the speculum exam, as well as one hour, and six hours post-treatment (Day 0). At the one hour and six hour post treatment time points, the direct vaginal pH readings were taken on specimens collected from two different positions in the vagina, in case of incomplete distribution of the IP soon after administration. Both readings are included as data points. At the six hour timepoint, subjects were trained on self-collecting vaginal swabs and performing the vaginal pH test. At 12 hours post-treatment, subjects performed the vaginal pH test themselves using self-obtained swabs, and record their results for clinician review.

Subjects stayed overnight in the domiciliary unit, and vaginal pH and Amsel criteria was measured again by research staff at 24 (+/- 2) hours post-treatment before discharge on Day 1. The subjects were discharged with the appropriate pH testing supplies and diary. All women agreed to abstain from sexual intercourse, douching and use of any intravaginally applied products or devices until after their final study visit on Day 7.

Subjects measured their vaginal pH at 24 (+/-2) hour intervals for 5 days (Days 2-6) as outpatients and recorded the pH test results, and any change in vaginal comfort, in a provided diary. Subjects also recorded any activities engaged in from the abstinence criteria in the study exclusion list, if applicable, each day. On Day 7, subjects returned to the clinic with their diaries, had their vaginal pH and Amsel criteria determined by the clinic staff, and queried as to any vaginal discomfort (vaginal comfort assessment) over the course of the study, as self-recorded in their diaries.

Inclusion Criteria:

1. Healthy female subjects between 18 and 45 years, inclusive
2. Ability to understand the consent process and procedures
3. Subjects agree to be available for all study visits
4. Written informed consent in accordance with institutional guidelines
5. Negative pregnancy test
6. Able and willing to comply with all study procedures
7. Have not engaged in sexual intercourse, douching or used of any form of vaginal suppository or intravaginal device for 24 hours prior to enrollment.
8. Agree to abstain from sexual intercourse, douching or any form of vaginal suppository or intravaginal device use during course of study
9. Report menstrual cycle regularity (25- to 35- day menstrual cycles)

Exclusion Criteria:

1. Participation in any study with an investigational compound or device within 30 days prior to signing informed consent
2. Active drug or alcohol use or dependence that, in the opinion of the investigator, would interfere with adherence to study protocol
3. Any other medical condition(s) that, in the judgment of the investigator, might interfere with the study or require treatment that might interfere with the study
4. Family member of the investigation study staff
5. Pregnant or breast-feeding
6. Inability to provide informed consent
7. A subject with a history or expectation of noncompliance with medications or treatment protocol
8. Women with symptoms of Urinary Tract Infection (UTI) or Sexually Transmitted Infection (STI) reported or observed during examination, at screening*.
9. Women who regularly use douches, vaginal medications or suppositories, feminine sprays, genital wipes or contraceptive spermicides, or report abnormal vaginal discharge in the past 48 hours prior to screening
10. Women who are menstruating or who would expect to menstruate during the study
11. Women who are currently using contraceptives that are directly delivered to the vaginal mucosa, such as NuvaRing
12. Any specific condition that, in the judgment of the Investigator, precludes participation because it could affect subject safety

Safety population

7 days

Low number of subjects at each time point and lost specimens meant a complete analyses were not conducted on specimens from all subjects at all time points and further studies are required to confirm these findings.