Local spermicidal contraception: a comparative study of the acceptability and safety of a new pharmaceutical formulation of benzalkonium chloride, the vaginal capsule, with a reference formulation, the pessary

Abstract

Objective To evaluate comparatively the acceptability and safety of a new pharmaceutical form of benzalkonium chloride, the vaginal capsule, with the pessary form.

Methods Eighty-nine women were randomized to receive either a benzalkonium chloride vaginal capsule or a benzalkonium chloride pessary prior to sexual intercourse according to an open cross-over design over a 2-month study period.

Results The discomfort caused by delayed leakage or discharge was mild. The mean scores for subjective signs (burning, itching, vulvar pruritus) were also mild and were comparable for the two formulations. The capsule appeared to be slightly superior to the pessary regarding discomfort caused by immediate discharge or leakage, ease of use and acceptance by the woman's partner.

Local safety was generally good. Adverse events consisted chiefly of vulvar pruritus and a vaginal or vulvar burning sensation, with a higher incidence being associated with the pessary than the capsule. All symptoms regressed spontaneously after the end of treatment.

Conclusions This study demonstrated good acceptability and good local safety for the benzalkonium chloride vaginal capsule. It is essential to take these parameters into consideration in the evaluation of any local spermicidal contraceptive, since they play a large part in compliance with, and thus in the efficacy of, the product under assessment.

KEY WORDS:

• Spermicide
• Contraception
• Benzalkonium chloride
• Acceptability