An overview of properties of Amphora (Acidform) contraceptive vaginal gel

ABSTRACT

Introduction: Although only a minority of contracepting women rely solely on spermicides, they may soon be the only ongoing female method available without a prescription in the United States. Spermicides are also combined with other methods for additional pregnancy protection and/or lubrication. Nonoxynol-9 (N-9), the active ingredient in most spermicides, is cytotoxic and may increase risk of transmission of HIV and other sexually transmitted infections, especially in high-risk women. Amphora (previously called Acidform) is a noncytotoxic spermicide composed of a series of generally regarded as safe compounds, which maintains the acidity of the vagina following coitus to immobilize and kill sperm. Amphora is currently Food and Drug Administration-approved as a vaginal lubricant. Amphora is currently being tested in a multicenter Phase III contraceptive trial.

Areas covered: This paper describes key properties of Amphora, including its acid-buffering abilities, viscosity, stability, bioadhesiveness, and tolerability.

Expert opinion: Amphora is a nontoxic spermicide that maintains the pH within the vagina at levels less than 5.0 for hours, which immobilizes and kills sperm as well as many sexually transmitted pathogens. If the current clinical trial demonstrates safety, efficacy, and tolerability of Amphora as a contraceptive, it would represent a viable alternative to N-9. Its potential as a microbicide warrants further investigation.

KEYWORDS:

• Amphora
• Acidform
• birth control
• vaginal contraception
• spermicide
• acid-buffering
• microbicide

Article highlights

• Amphora is a clear, highly viscous, bioadherent noncytotoxic vaginal spermicide that immobilizes and kills sperm by maintaining the acidic pH of the vagina in the face of the substantial buffering ability of semen

• Amphora was approved by the US FDA as a personal lubricant in 2004.

• Amphora is comprised of GRAS (Generally Regarded as Safe by the FDA) ingredients, including lactic acid.

• Amphora is currently in Phase III clinical trials in a single arm, 7-cycle trial in over 100 sites in the United States. An earlier comparative trial showed that Amphora offered contraceptive efficacy that was noninferior a commercially available N-9 gel.

• Amphora is a female-controlled method that would be available without prescription and is compatible for use alone or with other products for additional pregnancy protection (e.g. with male condoms, diaphragms, cervical caps) or for personal lubrication.

• Its potential in reducing selective STD transmission warrants further study.

Declaration of interest

ALN declares that she has received payments for research from Agile, ContraMed/Sebela, Estetra SPRL, Evofem Inc, FHI (MonaLisa), Mathra Phram, and Merck and honoraria for participation on advisory boards or speaker bureaus for Agile, Allergan, AMG Pharma, Bayer, ContraMed/Sebela, Merck and Pharmanest. ALN has received grant funding as principal investigator at one of the sites currently conducting a Phase III trial of the safety and efficacy of Amphora.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.