Properties of a new acid-buffering bioadhesive vaginal formulation (ACIDFORM)

Imiquimod-Loaded Nanosystem for Treatment Human Papillomavirus-Induced Lesions

Human papillomavirus (HPV)-associated cervical cancer is the most common cancer among women worldwide. The treatment options are strongly related to increased infertility in women. Imiquimod (IQ) is an imidazoquinoline, which has proven antiviral effects against persistent HPV infection by activating immune cells via Toll-like receptors 7/8 when formulated in carriers, like nanogels, for topical use. An effective alternative to conventional therapies is the nanoparticle drug delivery system. We studied lipidic nanoparticles with IQ (Lipo IQ) and functionalized them with a DNA aptamer, AT11 (Lipo IQ AT11), to improve the selectivity for cervical cancer cells combined with the efficacy of essential oils. The formulations showed that the physicochemical properties are adequate for vaginal drug delivery and have antimicrobial activity at higher concentrations (with MIC50 starting from 0.625%). The final formulations exhibited cytotoxicity in cancer cells, enhanced by essential oils without affecting healthy cells, resulting in less than 10% cell viability in HeLa cells and over 60% in NHDF cells. Essential oils potentiate Lipo IQ's effectiveness, while AT11 increases the selectivity for cervical cancer cells. As suggested by the results of the permeation assay, the formulations were internalized by the cancer cells. Overall, the obtained results suggested that the synergistic effect of the essential oils and the nanosystem potentiate the cytotoxic effect of Lipo IQ and that Lipo IQ AT11 promotes selectivity towards cancer cells.

Lactic acid, citric acid and potassium bitartrate non-hormonal prescription vaginal pH modulator (VPM) gel for the prevention of pregnancy

INTRODUCTION

A non-hormonal prescription vaginal pH modulator (VPM) gel (Phexxi®), with active ingredients lactic acid, citric acid and potassium bitartrate, has recently been approved for prevention of pregnancy in the United States. The objective of this review is to compile the evidence available from published preclinical and clinical trials to support its use.

AREAS COVERED

PubMed was searched for published literature on VPM gel. Two Phase III trials were found on clinicaltrials.gov database. The results demonstrated that VPM gel is safe, with minimal side effects, and effective (cumulative 6-7 cycle pregnancy rate of 4.1-13.65%, (Pearl Index 27.5) as a contraceptive. Microbicidal effects suggest potential for the prevention of sexually transmitted infections (STIs); currently a Phase III clinical trial is being conducted to evaluate prevention of chlamydia and gonorrhea.

EXPERT OPINION

Non-hormonal reversible contraceptive options have been limited to the highly effective copper-releasing intrauterine device that requires insertion by a trained clinician, and less effective coitally-associated barrier and spermicide options which are typically available over-the-counter. Spermicides, which improve efficacy of barrier devices, may increase the risk of HIV/STIs. VPM gel provides a new safe, effective non-hormonal contraceptive option, with potential for prevention of STIs.

Sexual Satisfaction Results With the Vaginal pH Modulator From the Phase 3 AMPOWER Study

BACKGROUND

The novel vaginal pH modulator (VPM; Phexxi) is a non-hormonal, woman-controlled, on-demand, water-based, surfactant-free contraceptive vaginal gel; VPM has also been cleared by the Food and Drug Administration for use as a personal lubricant.

AIM

The aim of this study is to report on sexual satisfaction results from the phase 3 AMPOWER study.

METHODS

AMPOWER was a single-arm, open-label, multicenter study to assess the safety and efficacy of VPM in preventing pregnancy. Women were enrolled who were healthy, age 18-35 years, and sexually active with regular cyclic menses.

OUTCOMES

Women's satisfaction (including sexual satisfaction) was an exploratory endpoint measured at Baseline and Visits 3-5; sexual satisfaction-related patient reported outcomes (PROs) were assessed via 3 different questions: (i) a question related to the impact on a woman's sex life; (ii) a question from the Sexual Function Questionnaire (SFQ) related to the frequency of ten sexual problems; and (iii) a question from the Female Sexual Function Index (FSFI) related to lubrication.

RESULTS

For sexual satisfaction-related PRO measures with baseline assessments, the majority of women reported the same or improved scores at Visit 5 (ranging from 85.8% to 98.4%). The percentage of women who reported that their sex life was improved and/or maintained was higher in Visit 3, 4, and 5 (95.4%, 95.1%, and 93.6%, respectively) compared to Baseline (87.6%). The mean impact on sex life score significantly improved at Visit 5 compared to Baseline (P < .001). In the SFQ, the mean score significantly improved (P < .005) at Visit 5 vs Baseline in 7 of the 10 variables measured (vaginal dryness, lack of sexual interest and/or desire, vaginal tightness, pain, anxiety, unable to orgasm, and vaginal bleeding or irritation). In women who reported sexual activity in the last 4 weeks, the mean FSFI score also significantly improved from Baseline to Visit 5 (P = .037).

CLINICAL IMPLICATIONS

In this post-hoc analysis of the phase 3 AMPOWER study, the PRO results demonstrate a high level of sexual satisfaction with VPM.

STRENGTHS AND LIMITATIONS

The primary strength of this analysis was the large study size of 1,330 women. Limitations included the non-randomized study design, the post-hoc nature of the analysis, and the fact that sexual satisfaction was an exploratory endpoint.

CONCLUSION

As a non-hormonal, woman-controlled, on-demand, lubricating contraceptive gel, VPM offers women a unique set of benefits with positive impacts on their sexual health. Thomas MA, Morlock R, Dart C, Howard B. Sexual Satisfaction Results With the Vaginal pH Modulator From the Phase 3 AMPOWER Study. J Sex Med 2022;19:975-982.

New Contraception Update — Annovera, Phexxi, Slynd, and Twirla

Purpose of Review

In this review, we discuss the efficacy, safety, and benefits of four new contraceptive products available in the USA, specifically Annovera, Phexxi, Slynd, and Twirla.

Recent Findings

Annovera is a vaginal ring releasing ethinyl estradiol and segesterone acetate that can be used for up to one year (13 cycles), offering patients an effective, user-controlled option that may improve contraceptive access for those in low-resource settings or those with barriers to retrieving monthly prescriptions; however, given limited efficacy and safety data in people with body mass index (BMI) > 29 kg/m2, clinicians may consider whether Annovera is an appropriate contraceptive method for obese patients if there are other acceptable alternatives. Phexxi prescription-only vaginal gel is a user-controlled, non-hormonal, on-demand contraceptive method that represents a novel addition to the market with its additional uses as a personal lubricant and as a potential microbicide for urogenital infection prevention. Slynd, a drospirenone-only pill, provides more flexibility for delayed or missed pills while maintaining efficacy and a more favorable bleeding profile compared with previously available progestin-only pills. Lastly, Twirla is a transdermal patch releasing ethinyl estradiol and levonorgestrel that offers users an additional option for a user-controlled, combined hormonal contraceptive method without daily dosing; however, prescription is limited to patients with BMI < 30 kg/m2 due to decreased efficacy and VTE events in people with obesity.

Summary

The addition of these products expands the available options for pregnancy prevention to address unmet contraceptive needs.

Mechanisms of action of currently available woman-controlled, vaginally administered, non-hormonal contraceptive products

Woman-controlled, vaginally administered contraceptives offer women discreet, self-administered, and reversible options. This brief report summarizes the mechanisms of action (MOAs) of currently available, woman-controlled, vaginally administered, non-hormonal products, excluding those that need to be fitted by a healthcare provider. MOAs of three general types of contraceptives will be reviewed, including pH modulators, spermicides, and barrier methods. The recently approved vaginal pH modulator (lactic acid, citric acid, and potassium bitartrate) has a non-hormonal MOA, acting as a buffering agent in the presence of alkaline semen and resulting in sperm immobilization. In contrast, spermicides, such as nonoxynol-9, act by lysing sperm membranes, resulting in sperm death. Barrier methods, such as the diaphragm and female condom, prevent sperm from entering the uterus. In addition to their varying MOAs, each woman-controlled, vaginally administered method has different instructions for use, efficacy, side effects, and availability/insurance coverage, thus providing a range of characteristics to fit different needs and preferences.

EVO100 prevents chlamydia and gonorrhea in women at high risk of infection

BACKGROUND

According to the Centers for Disease Control and Prevention, rates of infection for Chlamydia trachomatis and Neisseria gonorrhoeae are increasing in the United States. EVO100 is an investigational antimicrobial, pH-modulating, vaginal gel with active ingredients L-lactic acid, citric acid, and potassium bitartrate that is being evaluated for the prevention of sexually transmitted infections.

OBJECTIVE

The objective of this phase 2B/3 study was to assess the efficacy and safety of EVO100 for the prevention of chlamydia and gonorrhea.

STUDY DESIGN

AMPREVENCE was a double-blinded, placebo-controlled, multicenter study based in the United States conducted over approximately 16 weeks in women at the age of 18 to 45 years who were at risk of urogenital chlamydia and gonorrhea infection. Enrolled women had been diagnosed as having and treated for chlamydia or gonorrhea ≤16 weeks before enrollment. Women received either EVO100 or placebo vaginal gel and were instructed to apply the study drug immediately before or up to 1 hour before each act of vaginal sexual intercourse. The primary and secondary endpoints were the prevention of urogenital chlamydia and gonorrhea, respectively. Exploratory outcomes include women's overall satisfaction with EVO100.

RESULTS

In total, 860 women were randomized 1:1 to receive EVO100 (n=426) or placebo (n=434), and 764 women (EVO100, n=376; placebo, n=388) were documented as using the study drug at least once. Baseline characteristics were similar between treatment arms. Overall, women had a mean age of 27.7 years (standard deviation, 6.9) and body mass index of 28.9 kg/m² (standard deviation, 8.0). Most women were of White (54.3% [467 of 860]) or African American (41.6% [358 of 860]) race and of non-Hispanic/Latina ethnicity (67.1% [577 of 860]). The chlamydia infection rate in EVO100 users was 4.8% (14 of 289) compared with 9.7% (28 of 290) among placebo users (P=.0256), representing a relative risk reduction of 50%. For gonorrhea, the infection rate was 0.7% (2 of 280) in the EVO100 arm compared with 3.2% (9 of 277) in the placebo arm (P=.0316), representing a relative risk reduction of 78%. Increased efficacy was observed with increased adherence, and chlamydia infection rates were significantly reduced with increased adherence in the EVO100 group compared with placebo. Across both arms, there were similar rates of all-cause adverse events (EVO100, 21.3% [80 of 376]; placebo, 20.4% [79 of 388]) and treatment-related adverse events (EVO100, 7.2% [27 of 376]; placebo, 7.5% [29 of 388]). The most common adverse events in the EVO100 arm were vulvovaginal candidiasis (5.1% [19 of 376]), vaginal discharge (3.2% [12 of 376]), and urinary tract infection (3.2% [12 of 376]) and, in the placebo arm, bacterial vaginosis (4.6% [18 of 388]), urinary tract infection (2.6% [10 of 388]), and vaginal discharge (2.6% [10 of 388]). Few women discontinued owing to adverse events in either arm (EVO100, 1.1% [4 of 376]; placebo, 1.5% [6 of 388]). No treatment-related serious adverse events were reported. Most EVO100 users (88%) were satisfied or very satisfied with EVO100 after 16 weeks of use.

CONCLUSION

EVO100 significantly reduced the risk of chlamydia and gonorrhea infections in women at high risk of Chlamydia trachomatis and Neisseria gonorrhoeae infection and was well tolerated, with observed adverse events consistent with its known safety profile.

A novel vaginal pH regulator: results from the phase 3 AMPOWER contraception clinical trial

Objective

The objective was to evaluate the contraceptive effectiveness, safety, and acceptability of a novel vaginal pH regulator over seven cycles of use.

Study design

A single-arm, open-label, phase 3 study was conducted across 112 sites in the United States in sexually active 18–35-year-old women at risk of pregnancy. Women administered the study treatment ≤ 1 h before each episode of intercourse. Women recorded use of study drug, coital information, and any symptoms experienced in electronic diaries. The primary outcome was the seven-cycle cumulative pregnancy rate as calculated using the Kaplan–Meier methodology; secondary outcomes included safety. Overall satisfaction was assessed via written questionnaires.

Results

A total of 1384 women were enrolled in the study from July 2017 to November 2018. Mean age was 27.7 ± 4.4 years; most women were white (69.0%). The seven-cycle cumulative pregnancy percentage was 13.7% [95% confidence interval (CI): 10.0%–17.5%], meeting the prespecified primary endpoint of having the upper bound 95% CI ≤ 21%. Most common adverse events (AEs) occurring in ≥ 2% of women were vulvovaginal burning sensation, vulvovaginal pruritus, urinary tract infection, vulvovaginal pain, mycotic infection, bacterial vaginosis, and nasopharyngitis. Of 1330 women who used the study drug at least once, fewer than 2% of women discontinued due to any AEs, and < 1% of women discontinued due to genitourinary symptoms. Overall, > 80% of women reported being “very satisfied” or “satisfied” with study treatment.

Conclusions

In this phase 3 study, the novel vaginal pH regulator demonstrated 86.3% contraceptive effectiveness, was safe and well tolerated, and was highly acceptable.

Implications

This novel vaginal pH regulator is a safe, nonhormonal, woman-controlled method of contraception that expands women's options.

The vaginal sheet: an innovative form of vaginal film for the treatment of vaginal infections

Objective: To develop and characterize a new form of vaginal film.Significance: This formulation is intended to overcome some known limitations of traditional dosage forms. It has an absorptive intention to control symptoms and to improve the treatment of vaginal infections characterized by excessive fluid. The vaginal sheet is a thick drug delivery system easy to manipulate, nontoxic and composed by biocompatible macromolecules and polymers, such as gelatin and chitosan.Methods: The sheets were prepared by formulating gelatin or chitosan based gels isolated or in combination, in association with a plasticizer. Gels were subsequently lyophilized. Different proportions of polymer:plasticizer were tested. Lactose was used as a surrogate to study powder incorporation in the formulation. All formulations were analyzed regarding their organoleptic characteristics, texture (hardness and resilience), in vitro absorption efficiency of vaginal fluid simulant - VFS (pH 4 and 5), pH and acid-buffering capacity.Results: Different properties were obtained by varying polymer and plasticizer proportions. Combinations including gelatin with propylene glycol showed the best organoleptic characteristics. The best proportions were 4:3 and 4:5. Up to 10% of powder was successfully incorporated in the formulation. Hardness and resilience of formulations were largely dependent on the concentration of plasticizer. Absorption of vaginal fluid was found to be highly efficient, especially at pH 5. Buffering capacity, upon dilution in normal saline and VFS, was generally higher for VFS pH 4.Conclusions: The vaginal sheet is a promising solid drug delivery system able to further incorporate drugs to treat vaginal clinical conditions characterized by excessive fluid.

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

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.

Vaginal semisolid products: Technological performance considering physiologic parameters

Vaginal semisolid products are frequently used to treat vaginal infections and atrophy-related symptoms of menopause. Formulations composition and the methods for their characterization, especially those developed concerning the target epithelia, are key tools to predict in vivo results at early stages of product development. However, recent studies on this subject have been almost exclusively focused on anti-HIV preparations. The aim of this work consists on improving traditional characterization methods by using physiological parameters in order to construct predictive tools to characterize a new ideal vaginal semisolid formulation whatever target it may have. Ten vaginal antimicrobial and hormonal products already available in the market were studied (Gino-Canesten®, Sertopic®, Dermofix®, Gyno-pevaryl®, Lomexin®, Gino Travogen®, Dalacin V®, Ovestin®, Blissel®, Colpotrophine®). Furthermore, Universal Placebo gel and Replens® were used for comparison. Products were characterized in terms of: pH and buffering capacity in a vaginal fluid simulant (VFS); osmolality - directly and upon dilution in VFS; textural parameters (firmness, adhesiveness and bioadhesion) using vaginal ex vivo porcine epithelium; and viscosity (including VFS dilution at 37°C and after administration on an ex vivo model). Interestingly, the majority of the tested commercial vaginal formulations did not present technological characteristics close to the ideal ones when tested under target biological conditions. The inclusion of such methodologic adaptations is expected to optimize cost-efficiency of new formulations development by predicting efficacy and safety profiles at early stages of product development.

Transvaginal Diffusion of Synthetic Peptides

Topical microbicide peptides are being developed to combat the transfer of HIV, but little is known about the permeation of these compounds through vaginal epithelium. The object of the present study is to investigate the in vitro permeation of synthetic transport peptides through vaginal mucosa. The permeation kinetics of three FITC (fluorescein isothiocyanate)-labelled peptides MEA-5 (Mw = 2911.4 Da), MDY-19 (Mw = 2409.5 Da) and PCI (Mw = 2325 Da) across human vaginal mucosa was studied by means of a continuous flow-through diffusion system. Permeability studies were conducted at concentrations of 1 mM, 0.75 mM and 0.5 mM in PBS buffer at 37°C and 20°C, respectively, and over a time period of 24 h, using fluorospectrophotometry as detection method. Effects of a surfactant on MDY-19 permeation and de-epithelialisation of the vaginal mucosa were also studied. Statistical tests used included an ANOVA and Duncan's multiple range test to establish steady state diffusion kinetics. All three peptides readily penetrate vaginal mucosa. Microbicides may be coupled to MDY-19 and PCI to be transported transmucosally. Although increased size of the peptide/microbicides complex may decrease mucosal permeability, this could possibly be overcome by the addition of a permeation enhancer, e.g. a surfactant. Removal of the vaginal epithelium increased the flux rates of the peptides across the mucosa and may have implications for a more rapid uptake of these and other microbicides in vivo. Concentration- and temperature- dependency of peptide flux rates must be taken into consideration when performing in vitro permeability studies.

An update on multipurpose prevention technologies for the prevention of HIV transmission and pregnancy

INTRODUCTION

Multipurpose Prevention Technologies (MPTs) are designed to address two or more indications from a single product. The overall goal is to prevent unintended pregnancy and transmission of one or more STIs including HIV-1.

AREAS COVERED

The topics covered herein are advances in over the past three years. Advances include development of novel intravaginal rings capable of releasing microbicides to prevent transmission of HIV-1 and unintended pregnancy. These rings include the potential to prevent transmission of more than one STI and unintended pregnancy. There are also gels that can potentially accomplish the same thing. Finally, combination of a drug and barrier device are also covered.

EXPERT OPINION

There has been considerable advance in this field over the past three years. There is one ring currently in a Phase I clinical trial and others are soon to follow. Some of these drug delivery systems are by necessity rather complicated and hence could be prohibitively expensive in the developing world. Conducting multiple clinical trials to support regulatory approval of two or more indications represents a significant barrier. It remains unclear that women will be more motivated to use MPT products than has been observed in recent microbicide-only clinical trials. Despite these challenges, the need for MPTs remain acute hopefully ensuring they will continue to be developed over the coming years.

New strategies for local treatment of vaginal infections

Vaginal infections are extremely prevalent, particularly among women of reproductive age. Although they do not result in high mortality rates, these infections are associated with high levels of anxiety and reduction of quality of life. In most cases, topical treatment of vaginal infections has been shown to be at least as effective as oral treatment, resulting in higher local drug concentrations, with fewer drug interactions and adverse effects. Furthermore, the emergence of microbial resistance to chemotherapeutics and the difficulties in managing infection recurrences sustain the need for more effective local treatments. However, conventional dosage forms have been associated with low retention in the vagina and discomfort. Formulation strategies such as the development of bioadhesive, thermogelling systems and microtechnological or nanotechnological approaches have been proposed to improve delivery of traditional drugs, and other treatment modalities such as new drugs, plant extracts, and probiotics are being studied. This article reviews the recent strategies studied to improve the treatment and prevention of the commonest vaginal infections-namely, vaginal bacteriosis, aerobic vaginitis, vulvovaginal candidosis, and trichomoniasis-through the intravaginal route.

Recent advances on anti-HIV vaginal delivery systems development

A review of the recent outcomes regarding technologies to prevent vaginal transmission of HIV, mainly by using antiretroviral (ARV) drugs formulated as microbicides. An introduction about the HIV transmission mechanisms by the vaginal route is included, together with the recent challenges faced for development of successful microbicide products. The outcomes of clinical evaluations are mentioned, and the different formulation strategies studied to-date, with the requirements, advantages, disadvantages and limitations of each dosage-form type, are presented. Finally, the recent attempts to apply various types of nanotechnologies in order to develop advanced microbicide-products and overcome existing limitations, are discussed.

Characterization of commercially available vaginal lubricants: a safety perspective

Vaginal lubricants are widely used by women to help solve intercourse difficulties or as enhancers, but recent reports raise questions about their safety. Twelve commercially available gel products were tested for pH value, pH buffering capacity, osmolality and cytotoxicity relevant to vaginal delivery. Obtained data were analyzed in light of the recent Advisory Note by the World Health Organization (WHO) for personal lubricants to be concomitantly used with condoms. Results showed that most products do not comply with pH and osmolality recommended standards, thus posing a potential hazard. Four products presented values of osmolality around three-times higher than the maximum acceptable limit of 1200 mOsm/kg. In vitro cell testing further identified substantial cytotoxicity even at 1:100 dilutions for three products, contrasting with no significant effect of up to at least a 1:5 dilution of a Universal Placebo gel. However, no direct correlation between these last results and pH or osmolality was found, thus suggesting that the individual toxicity of specific formulation components plays an important role in the outcome of a particular product. Although further assessment is required, these results highlight potential safety issues related to the formulation of commercially available vaginal lubricants.

Poly(ethylene glycol) (PEG)-lactic acid nanocarrier-based degradable hydrogels for restoring the vaginal microenvironment

Women with bacterial vaginosis (BV) display reduced vaginal acidity, which make them susceptible to associated infections such as HIV. In the current study, poly(ethylene glycol) (PEG) nanocarrier-based degradable hydrogels were developed for the controlled release of lactic acid in the vagina of BV-infected women. PEG-lactic acid (PEG-LA) nanocarriers were prepared by covalently attaching lactic acid to 8-arm PEG-SH via cleavable thioester bonds. PEG-LA nanocarriers with 4 copies of lactic acid per molecule provided controlled release of lactic acid with a maximum release of 23% and 47% bound lactic acid in phosphate buffered saline (PBS, pH7.4) and acetate buffer (AB, pH4.3), respectively. The PEG nanocarrier-based hydrogels were formed by cross-linking the PEG-LA nanocarriers with 4-arm PEG-NHS via degradable thioester bonds. The nanocarrier-based hydrogels formed within 20 min under ambient conditions and exhibited an elastic modulus that was 100-fold higher than the viscous modulus. The nanocarrier-based degradable hydrogels provided controlled release of lactic acid for several hours; however, a maximum release of only 10%-14% bound lactic acid was observed possibly due to steric hindrance of the polymer chains in the cross-linked hydrogel. In contrast, hydrogels with passively entrapped lactic acid showed burst release with complete release within 30 min. Lactic acid showed antimicrobial activity against the primary BV pathogen Gardnerella vaginalis with a minimum inhibitory concentration (MIC) of 3.6 mg/ml. In addition, the hydrogels with passively entrapped lactic acid showed retained antimicrobial activity with complete inhibition G. vaginalis growth within 48 h. The results of the current study collectively demonstrate the potential of PEG nanocarrier-based hydrogels for vaginal administration of lactic acid for preventing and treating BV.

Formulation development and evaluation of innovative two-polymer (SR-2P) bioadhesive vaginal gel

The main objective of this investigation was to study the feasibility of developing a vaginal bioadhesive microbicide using a SRI's proprietary two-polymer gel platform (SR-2P). Several formulations were prepared with different combinations of temperature-sensitive polymer (Pluronic® F-127) and mucoadhesive polymer (Noveon® AA-1), producing gels of different characteristics. Prototype polymeric gels were evaluated for pH, osmolality, buffering capacity, and viscosity under simulated vaginal semen dilutions, and bioadhesivity using ex vivo mini pig vaginal tissues and texture analyzer. The pH of the polymeric gel formulations ranged from 5.1 to 6.4; the osmolality varied from 13 to 173 mOsm. Absolute viscosity ranged from 513 to 3,780 cPs, and was significantly reduced (1.5- to 3-fold) upon incubation with simulated vaginal and semen fluid mixture. Among the tested gels (indicated in the middle row as a molar ratio of a mixture of Noveon vs. Pluronic), only SR-2P retained gel structure upon dilution with simulated fluids and mild simulated coital stress. The pH of the SR-2P gel was maintained at about 4.6 in simulated vaginal fluid and also showed high peak force of adhesion in mini pig vaginal tissue. Furthermore, SR-2P gel caused no or only minimal irritation in a mouse vaginal irritation model. The results of this preliminary study demonstrated the potential application of SR-2P gel as a vaginal microbicide vehicle for delivery of anti-HIV agents.

ACIDFORM: a review of the evidence

OBJECTIVE

ACIDFORM is a candidate microbicide with spermicidal properties. A large Phase 3 trial is underway, and it is anticipated that this product will be approved for contraceptive use and marketed soon in the United States. The goal of this article is to critically review the evidence supporting the properties, safety profile and different uses of ACIDFORM gel.

STUDY DESIGN

We searched PubMed and Medline for any published literature on ACIDFORM.

RESULTS

ACIDFORM is an acidifying agent that works by lowering the vaginal pH to enhance the normal vaginal defenses. In addition to strong acid-buffering properties, ACIDFORM has high bioadhesive and viscosity-retaining properties. Several Phase 1 clinical trials have demonstrated the vaginal safety of ACIDFORM used alone or in combination with a diaphragm, although dose-dependent side effects appear to be present. Studies investigating the efficacy of ACIDFORM against sexually transmitted infections (STIs) are promising, but further trials are needed.

CONCLUSIONS

The properties of ACIDFORM offer many advantages for use, either alone or in combination with another active ingredient, such as Tenofovir. Potential applications for ACIDFORM include use as a personal lubricant, a vaginal contraceptive (alone or with a barrier method) and a microbicidal product or as a formulation vehicle for an active ingredient.

IMPLICATIONS

ACIDFORM is a candidate female-controlled vaginal preparation with microbicidal and spermicidal properties. A dual protection method could prevent unwanted pregnancies and reduce the risk of STI acquisition.

Microbicide dosage forms

Microbicides are topically applied, user controlled dosage forms that are being developed to prevent the transmission of HIV during coitus. Early candidates focused on coitally dependent dosage forms such as gels and creams. More recent development has focused on broadening the coitally dependent options through the introduction of films and fast dissolving tablets. Additionally, it has become important to have longer acting products to minimize the burden of user compliance and thus vaginal rings have been developed providing sustained delivery of antiretroviral drugs. This chapter discusses the history of microbicides along with a detailed description of coitally dependent products, gels, films, tablets diaphragms, as well as coitally independent dosage forms such as vaginal rings and the introduction of a new technology, electrospun fibers.

Phase I randomized safety study of twice daily dosing of acidform vaginal gel: candidate antimicrobial contraceptive

Background

Acidform gel, an acid-buffering product that inactivates spermatozoa, may be an effective topical non-hormonal contraceptive. This study was designed to evaluate the safety of vaginal dosing and effects of Acidform on mucosal immune mediators, antimicrobial properties of genital secretions, and vaginal microbiota.

Methods

Thirty-six sexually abstinent U.S. women were randomized to apply Acidform or hydroxyethylcellulose (HEC) placebo gel twice daily for 14 consecutive days. Safety was assessed by symptoms and pelvic examination. The impact of gel on mucosal immunity was assessed by quantifying cytokines, chemokines, antimicrobial proteins and antimicrobial activity of genital secretions collected by cervicovaginal lavage (CVL) at screening, 2 hours after gel application, and on days 7, 14 and 21. Vaginal microbiota was characterized at enrollment and day 14 using species-specific quantitative PCR assays.

Results

The median vaginal and cervical pH was significantly lower 2 hours after application of Acidform and was associated with an increase in the bactericidal activity of CVL against E. coli. However, 65% of women who received Acidform had at least one local adverse event compared with 11% who received placebo (p = 0.002). While there was no increase in inflammatory cytokines or chemokines, CVL concentrations of lactoferrin and interleukin-1 receptor antagonist (IL-1ra), an anti-inflammatory protein, were significantly lower following Acidform compared to HEC placebo gel application. There were no significant changes in Lactobacillus crispatus or Lactobacillus jensenii in either group but there was a decrease in Gardnerella vaginalis in the Acidform group (p = 0.08).

Conclusions

Acidform gel may augment mucosal defense as evidenced by an increase in bactericidal activity of genital secretions against E. coli and a decrease in Gardnerella vaginalis colonization. However, Acidform was associated with more irritation than placebo and lower levels of antimicrobial (lactoferrin) and anti-inflammatory (IL-1ra) proteins. These findings indicate the need for additional safety studies of this candidate non-hormonal contraceptive.

Trial Registration

ClinicalTrials.gov NCT00850837

The importance of the vaginal delivery route for antiretrovirals in HIV prevention

The HIV/AIDS pandemic continues to be a global health priority, with high rates of new HIV-I infections persisting in young women. One HIV prevention strategy is topical pre-exposure prophylactics or microbicides, which are applied vaginally or rectally to protect the user from HIV and possibly other sexually transmitted infections. Vaginal microbicide delivery will be the focus of this review. Multiple nonspecific and specific antiretroviral microbicide products have been clinically evaluated, and many are in preclinical development, The events of HIV mucosal transmission and dynamics of the cervicovaginal environment should be considered for successful vaginal microbicide delivery. Beyond conventional vaginal formulations, intravaginal rings, tablets and films are employed as platforms in the hope to increase the likelihood of microbicide use. Furthermore, combining multiple antiretrovirals within a given formulation, combining a microbicide product with a vaginal device and integrating novel drug-delivery strategies within a microbicide product are approaches to successful vaginal-microbicide delivery.

Multipurpose prevention technologies: biomedical tools to prevent HIV-1, HSV-2, and unintended pregnancies

Statistics clearly show an unmet need for highly effective contraception, especially in less developed countries. Many of these countries are at the core of the HIV/AIDS epidemic and show very high prevalence rates for other sexually transmitted infections (STIs) such as that caused by HSV-2. A woman at risk of unintended pregnancy due to unprotected intercourse is also at risk for HIV/STI. Owing to their causative interrelationship, combining protection against these conditions will result in enhanced prevention and health benefits. Existing multipurpose prevention modalities such as condoms and physical barriers, albeit efficacious, face cultural hurdles that have so far hindered their widespread use. Success has recently been demonstrated in large clinical trials, demonstrating proof of concept of microbicides in reducing the incidence of HIV-1 and HSV-2 among at-risk populations. The challenge heretofore is to refine these products to make them more potent, convenient, accessible, and acceptable. Potent antiviral drugs released topically in the female reproductive tract by innovative delivered systems and formulations will provide safe, effective, and acceptable multipurpose prevention tools. This paper provides an overview of existing and novel approaches to multipurpose prevention strategies.

Noninvasive routes of proteins and peptides drug delivery

Recent advances in the field of pharmaceutical biotechnology have led to the formulation of many protein and peptide-based drugs for therapeutic and clinical application. The route of administration has a significant impact on the therapeutic outcome of a drug. The needle and syringe is a well established choice of protein and peptide delivery which has some drawback related to patient and to formulation such as pain, cost, sterility etc. Thus, the noninvasive routes which were of minor importance as parts of drug delivery in the past have assumed added importance in protein and peptide drug delivery and these include nasal, ophthalmic, buccal, vaginal, transdermal and pulmonary routes. The pharmaceutical scientists have some approaches to develop the formulations for protein and peptide delivery by noninvasive routes. But, due to the physiochemical instability and enzymatic barrier of proteins and peptides there are several hurdle to develop suitable formulation. So there is need of penetration enhancers, enzyme inhibitors and suitable vehicles for noninvasive delivery to increase the bioavailability. In this review, the aim is to focus on the approaches to formulation of protein and peptide based drug administration by noninvasive route.

Effect of treatment assignment on intravaginal cleansing in a randomized study of the diaphragm with candidate microbicide

BACKGROUND

Intravaginal cleansing may predispose women to adverse health outcomes and may interfere with the effectiveness and safety of female-initiated methods for preventing sexually transmitted infections (STIs). In a 4-week randomized study of 192 Malagasy sex workers, we evaluated associations between self-reported intravaginal cleansing and randomization assignment: diaphragm with viscous candidate microbicide gel (Acidform™, TOPCAD, Chicago, IL, licensed to Instead, Coppell, TX), diaphragm with placebo hydroxyethylcellulose gel (HEC, ReProtect LLC, Baltimore, MD), Acidform alone, or HEC alone.

METHODS

Women were counseled to avoid intravaginal cleansing and were blinded to gel assignment. We evaluated changes in self-reported intravaginal cleansing across the study and assessed the effects of treatment assignment and covariates on frequent (more than once daily) intravaginal cleansing. Significant predictors in domain-specific models were evaluated in an all-domain multiple regression model.

RESULTS

The proportion of women reporting intravaginal cleansing decreased from baseline (97%) to week 1 (82%) (p < 0.001). Self-reported frequent intravaginal cleansing decreased from baseline (87% to 56%) during the same time period (p < 0.001). In adjusted analyses, the Acidform-diaphragm group had 60% lower odds of frequent intravaginal cleansing during the study (odds ratio [OR] 0.4, 95% confidence interval [CI] 0.2-0.8) compared to the control group (HEC only). HEC-diaphragm and Acidform only users did not differ from controls. Living on the coast of Madagascar, not cohabiting, frequent intravaginal cleansing at enrollment, and high coital frequency predicted frequent intravaginal cleansing during follow-up.

CONCLUSIONS

Gel characteristics and the diaphragm's presence likely influenced women's cleansing. Viscous gel delivered by a cervical barrier (such as a diaphragm) may minimize the likelihood of frequent intravaginal cleansing.

Novel approaches in fighting herpes simplex virus infections

The development of novel strategies to eradicate herpes simplex virus (HSV) is a global public health priority. While acyclovir and related nucleoside analogues provide successful modalities for treatment and suppression, HSV remains highly prevalent worldwide and is a major cofactor fueling the HIV epidemic. HSV is the predominant cause of genital ulcerative disease, and neonatal and sporadic infectious encephalitis. Asymptomatic shedding, which occurs more frequently than previously appreciated, contributes to viral transmission. Acyclovir resistance may be problematic for immunocompromised patients and highlights the need for new safe and effective agents. Ideally, vaccines to prevent infection, drugs to inhibit the establishment of or reactivation from latency, or vaginal microbicides to prevent sexual and perinatal transmission are needed to control the epidemic. This review summarizes current therapeutic options and strategies in development.

Microbicidal spermicide or spermicidal microbicide?

Vaginal contraception, the oldest method of fertility regulation that remained virtually forgotten for a few decades has recently come under focal review due to an increase in STDs and HIV infections worldwide. Today it is being considered very strongly that a conceptual microbicidal spermicide can tender protection against pregnancy as well as STDs (including AIDS), simultaneously. However the two activities (spermicidal and microbicidal) need to be integrated in vaginal preparations, as many women across the world may be concerned more about the unwanted pregnancy rather than the STI during a coital act. A strong detergent like nonoxynol-9 (N-9) has been used as a spermicide in many local contraceptive preparations and studies have shown that it also exhibits significant microbicidal activity in vitro. However, recent clinical trials have shown that detergent spermicides do not provide any protection against STDs and AIDS but may in fact even promote their transmission. This anomaly has largely been attributed to their surfactant nature that irritates the vagina and kills the normal vaginal flora making it more susceptible to STD infections. An urgent need for a suitable non-detergent spermicide has thus emerged to replace N-9 in local contraceptive preparations. Anticipating the potential of spermicide-based vaginal contraceptives in the reproductive health of women, a large number of synthetic, non-detergent molecules were designed and evaluated at this Institute over recent years. Simultaneously, a number of natural products from terrestrial plants and marine flora/fauna were also evaluated for spermicidal activity. A local contraceptive preparation incorporating the active ingredient from the fruit pericarp of Sapindus mukorossi has successfully completed Phase III clinical trials in India and is ready for marketing. Recent studies have indicated that in comparison to N-9, this ingredient is much less toxic to Lactobacillus spp. and effectively inhibits the growth of Trichomonas vaginalis in vitro. Other candidate spermicides/microbicides under development worldwide have been reviewed briefly.

Vaginal drug delivery systems for HIV prevention

Microbicides have become a principal focus for HIV prevention strategies. The successful design of drug delivery systems for vaginal microbicide drug candidates brings with it a multitude of challenges. It is imperative that the chemical and physical characteristics of the drug candidate and its mechanism of action be clearly understood and considered to successfully deliver and target drug candidates efficiently. In addition, an understanding of the dynamic nature of the vaginal environment, the tissue and innate barriers present, as well as patient preferences are critical considerations in the design of effective microbicide products. Although the majority of drug candidates clinically evaluated to date have been delivered using conventional semisolid aqueous-based gel dosage forms, drug delivery system design has recently been extended to include advanced delivery systems such as vaginal rings, quick-dissolve films, and tablets. Ultimately, it may be necessary to develop multiple dosage platforms for a single active agent to provide users with options that can be used within the constraints of their social environment, personal choice, and environmental conditions.

Vaginal microbicide and diaphragm use for sexually transmitted infection prevention: a randomized acceptability and feasibility study among high-risk women in Madagascar

BACKGROUND

In preparation for a randomized controlled trial (RCT), we conducted a pilot RCT of the acceptability and feasibility of diaphragms and candidate vaginal microbicide for sexually transmitted infection prevention among high-risk women in Madagascar.

METHODS

Participants were randomized to four arms: (1) diaphragm (worn continuously) with Acidform applied in the dome; (2) diaphragm (worn continuously) with placebo gel hydroxyethylcellulose (HEC) in the dome; (3) HEC applied intravaginally before sex; (4) Acidform applied intravaginally before sex. All women were given condoms. Participants were followed weekly for 4 weeks. We fit unadjusted negative binomial regression models with robust variance estimators to generate the proportion of sex acts with casual partners where condoms and experimental study products were used.

RESULTS

Retention was 98% among 192 participants. Experimental product use with casual partners was high, reported in 85%, 91%, 74%, and 81% of sex acts for women in the Acidform-diaphragm, HEC-diaphragm, HEC-alone, and Acidform-alone arms, respectively. However, the proportion reporting product use during 100% of acts with casual partners over the full follow-up period was much lower: 28% to 29% in the gel-diaphragm arms and 6% to 10% in gel-alone arms. Women used condoms in 62% to 67% of sex acts with casual partners, depending on the randomization arm. Participants found diaphragms easy to insert (97%) and remove (96%). Acidform users (with or without the diaphragm) reported more genitourinary symptoms than HEC users (14% vs. 5% of visits).

CONCLUSIONS

A sexually transmitted infection prevention RCT of candidate microbicide with and without the diaphragm appears acceptable and feasible in this population.

Phase I safety trial of two vaginal microbicide gels (Acidform or BufferGel) used with a diaphragm compared to KY jelly used with a diaphragm

OBJECTIVES

To assess the safety and acceptability of 2 vaginal microbicide gels (Acidform and BufferGel) used with a diaphragm compared to KY Jelly used with a diaphragm among low-risk, sexually abstinent women.

STUDY DESIGN

Eighty-one women enrolled in a randomized, masked, phase I safety study using a diaphragm with Acidform, BufferGel, or KY Jelly for 6 to 10 hours nightly for 14 nights. Physical examination, colposcopy, and lab studies were performed after 1 and 2 weeks of use. Diaries and questionnaires were used to assess user acceptability.

RESULTS

Sixty-nine participants (85%) completed the study. Safety and acceptability appeared similar among the 3 study groups and no serious adverse events related to the study products were reported. Adverse events were mild and anticipated.

CONCLUSIONS

Acidform and BufferGel compared to KY Jelly, when used with diaphragm daily for 14 days, appeared to be safe and acceptable in a small study of low-risk abstinent women.

Preclinical evaluation of lime juice as a topical microbicide candidate

BACKGROUND

The continued growth of the global HIV epidemic highlights the urgent need to develop novel prevention strategies to reduce HIV transmission. The development of topical microbicides is likely to take a number of years before such a product would be widely available. This has resulted in a call for the rapid introduction of simpler vaginal intervention strategies in the interim period. One suggested practice would be vaginal douching with natural products including lime or lemon juice. Here we present a comprehensive preclinical evaluation of lime juice (LiJ) as a potential intervention strategy against HIV.

RESULTS

Pre-treatment of HIV with LiJ demonstrated direct virucidal activity, with 10% juice inactivating the virus within 5 minutes. However, this activity was significantly reduced in the presence of seminal plasma, where inactivation required maintaining a 1:1 mixture of neat LiJ and seminal plasma for more than 5 minutes. Additionally, LiJ demonstrated both time and dose-dependent toxicity towards cervicovaginal epithelium, where exposure to 50% juice caused 75-90% toxicity within 5 minutes increasing to 95% by 30 minutes. Cervicovaginal epithelial cell monolayers were more susceptible to the effects of LiJ with 8.8% juice causing 50% toxicity after 5 minutes. Reconstructed stratified cervicovaginal epithelium appeared more resilient to LiJ toxicity with 30 minutes exposure to 50% LiJ having little effect on viability. However viability was reduced by 75% and 90% following 60 and 120 minutes exposure. Furthermore, repeat application (several times daily) of 25% LiJ caused 80-90% reduction in viability.

CONCLUSION

These data demonstrate that the virucidal activity of LiJ is severely compromised in the presence of seminal plasma. Potentially, to be effective against HIV in vivo, women would need to apply a volume of neat LiJ equal to that of an ejaculate, and maintain this ratio vaginally for 5-30 minutes after ejaculation. Data presented here suggest that this would have significant adverse effects on the genital mucosa. These data raise serious questions about the plausibility and safety of such a prevention approach.

Reversible female contraception: current options and new developments

Uncontrolled fertility results in significant infant and maternal mortality and morbidity. Contraception has the potential to reduce this disease burden. Although a rich array of reversible contraceptive methods exists, the need for more effective and user-friendly methods remains. Access to methods and affordability are major barriers in many parts of the world. However, in other areas, successful utilization is limited by convenience factors or a lack of appreciation of fertility risk. To address these issues, new products that require little user effort have been developed. To encourage correct and consistent use of other methods, noncontraceptive benefits are being popularized and new protocols to initiate contraceptive use immediately are being introduced. This review briefly discusses existing contraceptive methods and new developments that are under investigation.

Chitosan gels for the vaginal delivery of lactic acid: relevance of formulation parameters to mucoadhesion and release mechanisms

The aim of this work was to assess the effect of formulation parameters of a mucoadhesive vaginal gel based on chitosan and lactic acid, and to highlight its release mechanisms. Two molecular weight chitosans were used to prepare gels with 2 lactic acid concentrations. Both chitosan molecular weight and lactic acid concentration had a significant and mutually dependent influence on mucoadhesion, measured on pig vaginal mucosa. Similarly, the lactate release profiles were found to be dependent on lactic acid content and polymer molecular weight. One gel formulation based on the stoichiometric lactate to chitosan ratio was subjected to release test in media with 2 different counterions and increasing ionic strength. This test demonstrated that the lactate release is mainly due to ionic displacement.

Microbicides: a new frontier in HIV prevention

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections (STIs) including HIV-1. Despite more than two decades of HIV-1 vaccine research, there is still no efficacious HIV-1 vaccine, and the scientific community appears skeptical about the short or long-term feasibility of developing a vaccine that has the ability to induce sterilizing immunity against HIV-1. In this setting, microbicide research has gathered momentum. Currently, 16 candidate microbicides are in clinical development and five products are being evaluated in large-scale Phase 2B/3 effectiveness studies. Initial data from these trials will be available within the next 2-3 years, and it is feasible that there could be one or more licensed microbicides by the end of the decade. The first generation of surfactant microbicides had a non-specific mechanism of action. However, subsequent candidate microbicides have been developed to target specific steps in the process of viral transmission. The purpose of this article is to provide an overview of microbicide development and an update on the candidate pipeline.

Role of seminal plasma in the anti-HIV-1 activity of candidate microbicides

Background

Evaluation of microbicides for prevention of HIV-1 infection in macaque models for vaginal infection has indicated that the concentrations of active compounds needed for protection by far exceed levels sufficient for complete inhibition of infection in vitro. These experiments were done in the absence of seminal plasma (SP), a vehicle for sexual transmission of the virus. To gain insight into the possible effect of SP on the performance of selected microbicides, their anti-HIV-1 activity in the presence, and absence of SP, was determined.

Methods

The inhibitory activity of compounds against the X4 virus, HIV-1 IIIB, and the R5 virus, HIV-1 BaL was determined using TZM-bl indicator cells and quantitated by measuring β-galactosidase induced by infection. The virucidal properties of cellulose acetate 1,2-benzene-dicarboxylate (CAP), the only microbicide provided in water insoluble, micronized form, in the presence of SP was measured.

Results

The HIV-1 inhibitory activity of the polymeric microbicides, poly(naphthalene sulfonate), cellulose sulfate, carrageenan, CAP (in soluble form) and polystyrene sulfonate, respectively, was considerably (range ≈ 4 to ≈ 73-fold) diminished in the presence of SP (33.3%). Formulations of micronized CAP, providing an acidic buffering system even in the presence of an SP volume excess, effectively inactivated HIV-1 infectivity.

Conclusion

The data presented here suggest that the in vivo efficacy of polymeric microbicides, acting as HIV-1 entry inhibitors, might become at least partly compromised by the inevitable presence of SP. These possible disadvantages could be overcome by combining the respective polymers with acidic pH buffering systems (built-in for formulations of micronized CAP) or with other anti-HIV-1 compounds, the activity of which is not affected by SP, e.g. reverse transcriptase and zinc finger inhibitors.

A pilot clinical trial comparing an acid-buffering formulation (ACIDFORM gel) with metronidazole gel for the treatment of symptomatic bacterial vaginosis

AIM

To compare the effectiveness of an acid-buffering formulation gel (ACIDFORM) with metronidazole gel in the treatment of symptomatic bacterial vaginosis (BV).

METHODS

After a confirmed diagnosis of BV according to the criteria established by Nugent and Amsel, 30 nonpregnant women were enrolled in a randomized, double-blind clinical study. The women were randomly assigned to receive either 5 g ACIDFORM gel (n = 13) or 10% metronidazole gel (n = 17) intravaginally once daily for five consecutive days. Participants were evaluated in two follow-up visits (7-12 days and 28-35 days after treatment). Therapeutic success was defined as the presence of less than three of Amsel's criteria. If three or more criteria were present at first or second follow-up visit, the woman was excluded from the study and treated orally with metronidazole. Nugent scores were recorded at each visit but these were not used to define cure.

RESULTS

At the first follow-up visit, 15 (88%) of the women in the metronidazole group were cured compared with only three (23%) in the ACIDFORM group (P < 0.001). The remaining 12 women (10 of the ACIDFORM group and two of the metronidazole group) were considered as failure and were treated orally with metronidazole. At the second follow-up visit, two of the ACIDFORM-treated women and six of the metronidazole-treated women presented recurrent BV. Four women in the ACIDFORM group and one in the metronidazole group reported occasional burning and itching during product use.

CONCLUSION

ACIDFORM gel was significantly less effective than high-dose metronidazole gel for the treatment of symptomatic BV.

Role of mucosal immunity in preventing genital herpes infection

The female genital tract is immunologically unique because it must be tolerant to spermatozoa, pregnancy, and vaginal flora, but also protect the host from pathogen challenge. The mucosal response to herpes simplex viruses (HSV), a major cause of genital ulcerative disease and critical co-factor in the HIV/AIDS epidemic, is complex and consists of the normally acidic vaginal environment, constitutively secreted and induced antimicrobial peptides, complement, and cellular responses mediated by epithelial and immune cells. This review summarizes our current understanding of the mucosal response to HSV focusing on those factors that may prevent initial infection. Understanding how each of these components contribute to innate immunity, mechanisms of antiviral activity, and whether the virus has evolved strategies to evade their effects may lead to the development of novel vaginal microbicides.

Vaginal safety after use of a bioadhesive, acid-buffering, microbicidal contraceptive gel (ACIDFORM) and a 2% nonoxynol-9 product

BACKGROUND

ACIDFORM is a microbicidal and contraceptive candidate with strong buffering capacity.

METHODS

This was a Phase I blinded, randomized and crossover clinical study on two products, ACIDFORM and a commercial nonoxynol-9 (N-9) product (2%), evaluating their vaginal safety in 20 couples aged between 19 and 45 years. The women had regular menses, underwent previous tubal ligation, were not breast-feeding, had no vaginal sign and symptom and were in a stable partnership; both partners had no previous STI. Colposcopy, vaginal microbiology, inflammation markers and subject complaints were studied after coitus. Women were randomly assigned sequentially to receive ACIDFORM 0-30 min (0-30 min before intercourse), ACIDFORM 8-10 h (8-10 h before intercourse) or N-9 0-30 min after a control cycle.

RESULTS

Mild/moderate vulvar irritation was observed in five postcoital test colposcopies, burning and pruritus were reported in six treated cycles and non-irritation-related symptoms were found in five cycles with different treatments. No difference in vaginal pH, Nugent scores, H2O2-producing lactobacillus or leukocytes and interleukin 6 in the cervicovaginal lavage was found between the treatment and control cycles.

CONCLUSIONS

ACIDFORM appears to be safe for clinical use once a day. There is a potential spermicidal-microbicidal role for ACIDFORM as a vaginal flora helper or as a vehicle for products, except N-9.