International Journal of Gynecology and Obstetrics 85 (2004) 298–300 0020-7292/04/$30.00  2004 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijgo.2004.03.003 Brief communication Efficacy of a novel pH-buffering tampon in preserving the acidic vaginal pH during menstruation  A. Brzezinski *, T. Stern , R. Arbel , G. Rahav , Simon Benita a, b a c b Department of Obstetrics and Gynecology, Hadassah Medical Center, Jerusalem, Israel a Department of Pharmaceutics, The School of Pharmacy, Faculty of Medicine, The Hebrew University, Israel b Department of Microbiology and Infectious diseases, Hadassah Medical Center, Jerusalem, Israel c Received 27 October 2003; received in revised form 18 March 2004; accepted 18 March 2004 Keywords: Tampon; Vaginal pH; pH buffering; Vaginosis The vagina of a reproductive-age woman has a pH between 4 and 5. During menstruation, the vagina becomes less acidic due to the presence of menstrual fluid and diminished population of lac- tobacilli w1x. If the vagina becomes less acidic, the protective barrier provided by the normal acidic condition of the vagina becomes less effective and colonization by pathogenic microorganisms tends to appear w2x. The antimicrobial activity of the vaginal fluids is correlated with low pH and high lactic acid content w3x. This clinical trial, the first in humans, was designed to test the ability of a unique new bifunctional tampon (Rostam Ltd. Caesarea, Israel) to preserve the acidic pH of the vagina during menstruation. The tampon contains a polymeric delivery sys- tem (strips) that upon absorption of menstrual fluid gradually releases lactic acid and citric acid. The safety of the formulated novel tampon has  The study was partially presented at the annual meeting of the Society for Gynecologic Investigation (SGI) Washington DC March 2003. *Corresponding author. Tel.: q972-2-6776424; fax: q972- 2-6433337. E-mail address: amnonb@cc.huji.ac.il (A. Brzezinski). been established in two animal studies using exter- nal approved GLP facilities (Harlan Biotech Israel Ltd. Rehovot, Israel). No skin sensitization was observed in guinea pig maximization test and no significant irritation was noted in rabbit vaginal irritation test. The study was a randomized, double blind, placebo-controlled, crossover study, in which healthy volunteers, with regular menstrual cycles, used test tampons and identically looking regular tampons during two consecutive menstrual cycles according to random allocation. The study consist- ed of a screening_baseline visit, a menstruation visit (day 3 or 4 of the menses), and a follow-up visit (4–7 days prior to the next period). The same sequence of visits was performed for the subsequent menstrual cycle. Subjects who had abnormal vaginal discharge or abnormal growth of pathogenic microorganism in the initial vaginal culture were excluded from the study. Each visit the subjects were evaluated for vaginal pH and tampon pH (when applicable) and microbiologic cultures (using a standard sterile swab) were obtained. Subjects were instructed to use ychange the tampons according to their individual habits and needs.