A dosing study of nonoxynol-9 and genital irritation

Synthesis and Optimization of Small Molecule Inhibitors of Prostate Specific Antigen

Semen liquefaction is a postejaculation process that transforms semen from a gel-like (coagulated) form to a water-like consistency (liquefied). This process is primarily regulated by serine proteases from the prostate gland, most prominently, prostate-specific antigen (PSA; KLK3). Inhibiting PSA activity has the potential to impede liquefaction of human semen, presenting a promising target for nonhormonal contraception in the female reproductive tract. This study employed triazole B1 as a starting compound. Through systematic design, synthesis, and optimization, we identified compound 20 (CDD-3290) as a 216 nM inhibitor of PSA with better stability in media than triazole B1. Further, we also evaluated the selectivity profile of compound 20 (CDD-3290) by testing against closely related proteases and demonstrated excellent inhibition of PSA versus α-chymotrypsin and elastase and similar potency versus thrombin. Thus, compound 20 is an improved PSA inhibitor that can be tested for efficacy in vitro or in the female reproductive tract.

Vaginal irritation testing-prospects of human organotypic vaginal tissue culture models

Personal lubricants intended for local or systemic delivery via the vaginal route can induce vaginal irritation, damage the vaginal epithelial barrier which can enhance microbial entry, induce inflammation, and alter the microbiome of the vaginal ecosystem. Therefore, manufacturers of personal lubricants and medical devices are required to show biocompatibility and safety assessment data to support regulatory decision-making within a specified context of use. Furthermore, due to ethical concerns and the introduction of the 7th amendment of the European Council Directive which bans animal testing for cosmetic ingredients and products coupled with the Food and Drug Administration modernization Act 2.0 guidelines, there is a wave of drive to develop alternative test methods to predict human responses to chemical or formulation exposure. In this framework, there is a potential to use three-dimensional organotypic human vaginal-ectocervical tissue models as a screening tool to predict the vaginal irritation potential of personal lubricants and medicaments. To be physiologically relevant, the in vitro tissue models need to be reconstructed using primary epithelial cells of the specific organ or tissue and produce organ-like structure and functionality that recapitulate the in vivo-like responses. Through the years, progress has been made and vaginal tissue models are manufactured under controlled conditions with a specified performance criterion, which leads to a high level of reproducibility and reliability. The utility of vaginal tissue models has been accelerated in the last 20 years with an expanded portfolio of applications ranging from toxicity, inflammation, infection to drug safety, and efficacy studies. This article provides an overview of the state of the art of diversified applications of reconstructed vaginal tissue models and highlights their utility as a tool to predict vaginal irritation potential of feminine care products.

ZB-06, a vaginal film containing an engineered human contraceptive antibody (HC4-N), demonstrates safety and efficacy in a phase 1 postcoital test and safety study

BACKGROUND

With an unplanned pregnancy rate of 50% or more in many countries, there is an urgent need for contraceptives that are more accessible and acceptable. To meet the growing demand for new contraceptives, ZabBio developed ZB-06, a vaginal film containing HC4-N, a human contraceptive antibody that inactivates sperm.

OBJECTIVE

This study aimed to assess the potential contraceptive activity of the ZB-06 film using a surrogate assessment for contraceptive efficacy, the postcoital test. We also assessed clinical safety of film use among healthy heterosexual couples. Serum, cervical mucus, and vaginal fluid HC4-N antibody concentrations and sperm agglutination potency were determined after single film use. Changes in the concentration of soluble proinflammatory cytokines and vaginal Nugent score after film use were measured as subclinical safety endpoints.

STUDY DESIGN

This was a phase 1, first-in-woman, open-label, proof-of-concept, postcoital test and safety study.

RESULTS

A total of 20 healthy women were enrolled in the study, and 8 heterosexual couples completed all study visits. The product was safe for both female participants and their male sexual partners. The postcoital test performed on ovulatory cervical mucus at baseline (no product use) revealed a mean of 25.9 (±30.6) progressively motile sperm per high-power field. After use of a single ZB-06 film before intercourse, this number dropped to 0.04 (±0.06) progressively motile sperm per high-power field (P<.0001). At the follow-up postcoital test visit approximately 1 month later (no product use), a mean of 47.4 (±37.4) progressively motile sperm per high-power field was observed, indicating contraceptive reversibility.

CONCLUSION

A single dose of the ZB-06 film applied before intercourse was safe and met efficacy surrogate benchmarks of excluding progressively motile sperm from ovulatory cervical mucus. These data indicate that ZB-06 is a viable contraceptive candidate warranting further development and testing.

Comparative in vitro study on the local tolerance and efficacy of benzalkonium chloride, myristalkonium chloride and nonoxynol-9 as active principles in vaginal contraceptives

BACKGROUND

Spermicides have been identified as a potentially attractive alternative to hormonal contraceptives and/or intrauterine devices. Thus, this study aimed evaluating the efficacy and local tolerance of benzalkonium chloride (BKC) and myristalkonium chloride (MKC) contained in Pharmatex^® vaginal formulations and compare them with nonoxynol-9 (N-9), the most common active ingredient in topical vaginal contraceptives.

METHODS

Human normozoospermic samples were assessed for motility, viability, acrosome status and penetration ability after exposure to control, N-9 or different BKC and MKC doses for 0 and 10 minutes. Local tolerance on HeLa cells was evaluated by the Trypan-blue and MTT assays.

RESULTS

Exposure to BKC and MKC reduced acrosome integrity while promoting total immobilisation and complete loss of sperm viability (p < .001, n = 15). Both compounds also compromised sperm penetration ability upon exposure (p < .001, n = 15). N-9 induced the same outcomes (p < .001, n = 15); nevertheless, it was more toxic to HeLa cells than BKC and MKC (p < .05, n = 14).

CONCLUSIONS

BKC and MKC present strong in vitro spermicidal activity at lower doses than N-9 and were better tolerated after immediate exposure than N-9. Available Pharmatex^® galenic formulations were as effective as products based on N-9.

Amended Final Report on the Safety Assessment of Nonoxynol-1, -2, -3, -4, -5, -6, -7, and -81

Nonoxynol-1, -2, -3, -4, -5, -6, -7, and -8 (low molecular weight Nonoxynols) are ethoxylated alkylphenols used in cosmetic formulations as surfactants-emulsifying agents, principally in hair dyes and colors. The safety of Nonoxynols were assessed previously (Elder, R. L., ed. 1983. Final report on the safety assessment of Nonoxynol-2, -4, -8, -9, -10, -12, -14, -15, -30, -40, and -50. J. Am. Coll. Toxicol. 2:35–60). This report amends the conclusion on Nonoxynol-2, -4, and -8 reached in that report. There was no significant skin penetration using cadaver skin in which Nonoxynols-2, -4, and -9 were applied in conditions simulating leave-on or rinse-off applications. Under both conditions, the total skin penetration of Nonoxynol-2, -4, and -9 was less than 1% over a 48-hour period. Results of acute oral toxicity studies indicated that these low molecular weight Nonoxynols were at most slightly toxic. Nonoxynol-5 and -6 produce severe ocular irritation in test animals. They also produce skin irritation in test animals, but are not sensitizers. Due to the severity of ocular irritation reactions in animals, avoiding the use of products containing low molecular weight Nonoxynols in the area surrounding the eyes was discussed. The no-adverse-effect level in reproductive and developmental toxicity tests in which Nonoxynol-9 was delivered orally or intravaginally was higher than any possible exposure from cosmetic products. There was no evidence for genotoxicity or carcinogenicity. Ethylene oxide residues, although present in small amounts in several preparations, were not considered sufficient to present a carcinogenesis risk. The report discusses the need to ensure that the use of cosmetic products containing Nonoxynols should not result in ethylene oxide exposures above 0.1 mg/day. Unreacted nonylphenol may be present in low molecular weight Nonoxynols, but levels appear to be <500 ppm. The report discusses the need for cosmetic product formulators to exercise care so that any Nonylphenol in finished products is not found in toxic amounts. Clinical studies using Nonoxynol-9 showed irritation of the vaginal mucosa, along with increased epithelial disruption. A 2% solution of Nonoxynol-8.3 and -9 was sensitizing in dermatitis patients. A repeat insult patch test in normal volunteers using Nonoxynol-2 at a concentration of 5 % showed no evidence of allergic contact dermatitis, but there were reactions at 10%. Based on the available animal and clinical data, Nonoxynols-1 through -8 are safe as used in rinse-off products and safe for use in leave-on products at concentrations no greater than 5%.

Mechanism of semen liquefaction and its potential for a novel non-hormonal contraception†

Semen liquefaction is a proteolytic process where a gel-like ejaculated semen becomes watery due to the enzymatic activity of prostate-derived serine proteases in the female reproductive tract. The liquefaction process is crucial for the sperm to gain their motility and successful transport to the fertilization site in Fallopian tubes (or oviducts in animals). Hyperviscous semen or failure in liquefaction is one of the causes of male infertility. Therefore, the biochemical inhibition of serine proteases in the female reproductive tract after ejaculation is a prime target for novel contraceptive development. Herein, we will discuss protein components in the ejaculates responsible for semen liquefaction and any developments of contraceptive methods in the past that involve the liquefaction process.

Personal and Clinical Vaginal Lubricants: Impact on Local Vaginal Microenvironment and Implications for Epithelial Cell Host Response and Barrier Function

BACKGROUND

A majority of US women report past use of vaginal lubricants to enhance the ease and comfort of intimate sexual activities. Lubricants are also administered frequently in clinical practice. We sought to investigate if hyperosmolar lubricants are toxic to the vaginal mucosal epithelia.

METHODS

We tested a panel of commercially available lubricants across a range of osmolalities in human monolayer vaginal epithelial cell (VEC) culture and a robust 3-dimensional (3-D) VEC model. The impact of each lubricant on cellular morphology, cytotoxicity, barrier targets, and the induction of inflammatory mediators was examined. Conceptrol, containing nonoxynol-9, was used as a cytotoxicity control.

RESULTS

We observed a loss of intercellular connections, and condensation of chromatin, with increasing lubricant osmolality. EZ Jelly, K-Y Jelly, Astroglide, and Conceptrol induced cytotoxicity in both models at 24 hours. There was a strong positive correlation (r = 0.7326) between lubricant osmolality and cytotoxicity in monolayer VECs, and cell viability was reduced in VECs exposed to all the lubricants tested for 24 hours, except McKesson. Notably, select lubricants altered cell viability, barrier targets, and inflammatory mediators in 3-D VECs.

CONCLUSIONS

These findings indicate that hyperosmolar lubricants alter VEC morphology and are selectively cytotoxic, inflammatory, and barrier disrupting in the 3-D VEC model.

Serine protease inhibitor disrupts sperm motility leading to reduced fertility in female mice†

Inhibition of the sperm transport process in the female reproductive tract could lead to infertility. We previously showed that a pan-serine protease inhibitor, 4-(2-aminoethyl)benzenesulfonyl fluoride (AEBSF), blocked semen liquefaction in vivo and resulted in a drastic decrease in the number of sperm in the oviduct of female mice. In this study, we used a mouse model to test the efficacy of AEBSF as a reversible contraceptive, a sperm motility inhibitor, and a spermicide. Additionally, this study evaluated the toxicity of AEBSF on mouse vaginal tissues in vivo and human endocervical cells in vitro. We found that female mice treated with AEBSF had significantly less pups born per litter as well as fertilization rates in vivo compared to the vehicle control. We then showed that AEBSF reduced sperm motility and fertilization capability in vitro in a dose-dependent manner. Furthermore, AEBSF also exhibited spermicidal effects. Lastly, AEBSF treatment in female mice for 10 min or 3 consecutive days did not alter vaginal cell viability in vivo, similar to that of the vehicle and non-treated controls. However, AEBSF decreased cell viability of human ectocervical (ECT) cell line in vitro, suggesting that cells in the lower reproductive tract in mice and humans responded differently to AEBSF. In summary, our study showed that AEBSF can be used as a prototype compound for the further development of novel non-hormonal contraceptives for women by targeting sperm transport in the female reproductive tract.

Cervical epithelial damage promotes Ureaplasma parvum ascending infection, intrauterine inflammation and preterm birth induction in mice

Around 40% of preterm births are attributed to ascending intrauterine infection, and Ureaplasma parvum (UP) is commonly isolated in these cases. Here we present a mouse model of ascending UP infection that resembles human disease, using vaginal inoculation combined with mild cervical injury induced by a common spermicide (Nonoxynol-9, as a surrogate for any mechanism of cervical epithelial damage). We measure bacterial load in a non-invasive manner using a luciferase-expressing UP strain, and post-mortem by qPCR and bacterial titration. Cervical exposure to Nonoxynol-9, 24 h pre-inoculation, facilitates intrauterine UP infection, upregulates pro-inflammatory cytokines, and increases preterm birth rates from 13 to 28%. Our results highlight the crucial role of the cervical epithelium as a barrier against ascending infection. In addition, we expect the mouse model will facilitate further research on the potential links between UP infection and preterm birth.

Vulvovaginal candidiasis: Epidemiology, microbiology and risk factors

Vulvovaginal candidiasis (VVC) is an infection caused by Candida species that affects millions of women every year. Although Candida albicans is the main cause of VVC, the identification of non-Candida albicans Candida (NCAC) species, especially Candida glabrata, as the cause of this infection, appears to be increasing. The development of VVC is usually attributed to the disturbance of the balance between Candida vaginal colonization and host environment by physiological or nonphysiological changes. Several host-related and behavioral risk factors have been proposed as predisposing factors for VVC. Host-related factors include pregnancy, hormone replacement, uncontrolled diabetes, immunosuppression, antibiotics, glucocorticoids use and genetic predispositions. Behavioral risk factors include use of oral contraceptives, intrauterine device, spermicides and condoms and some habits of hygiene, clothing and sexual practices. Despite a growing list of recognized risk factors, much remains to be elucidated as the role of host versus microorganisms, in inducing VVC and its recurrence. Thus, this review provides information about the current state of knowledge on the risk factors that predispose to VVC, also including a revision of the epidemiology and microbiology of VVC, as well as of Candida virulence factors associated with vaginal pathogenicity.

A Pilot Study Measuring the Distribution and Permeability of a Vaginal HIV Microbicide Gel Vehicle Using Magnetic Resonance Imaging, Single Photon Emission Computed Tomography/Computed Tomography, and a Radiolabeled Small Molecule

Vaginal microbicide gels containing tenofovir have proven effective in HIV prevention, offering the advantage of reduced systemic toxicity. We studied the vaginal distribution and effect on mucosal permeability of a gel vehicle. Six premenopausal women were enrolled. In Phase 1, a spreading gel containing (99m)technetium-DTPA ((99m)Tc) radiolabel and gadolinium contrast for magnetic resonance imaging (MRI) was dosed intravaginally. MRI was obtained at 0.5, 4, and 24 h, and single photon emission computed tomography with conventional computed tomography (SPECT/CT) at 1.5, 5, and 25 h postdosing. Pads and tissues were measured for activity to determine gel loss. In Phase 2, nonoxynol-9 (N-9), containing (99m)Tc-DTPA, was dosed as a permeability control; permeability was measured in blood and urine for both phases. SPECT/CT showed the distribution of spreading gel throughout the vagina with the highest concentration of radiosignal in the fornices and ectocervix; signal intensity diminished over 25 h. MRI showed the greatest signal accumulation in the fornices, most notably 1-4 h postdosing. The median (interquartile range) isotope signal loss from the vagina through 6 h was 29.1% (15.8-39.9%). Mucosal permeability to (99m)Tc-DTPA following spreading gel was negligible, in contrast to N-9, with detectable radiosignal in plasma, peaking at 8 h (5-12). Following spreading gel dosing, 0.004% (0.001-2.04%) of the radiosignal accumulated in urine over 12 h compared to 8.31% (7.07-11.01%) with N-9, (p=0.043). Spreading gel distributed variably throughout the vagina, persisting for 24 h, with signal concentrating in the fornices and ectocervix. The spreading gel had no significant effect on vaginal mucosal permeability.

Blocking HIV-1 transmission in the female reproductive tract: from microbicide development to exploring local antiviral responses

The majority of new HIV-1 infections are transmitted sexually by penetrating the mucosal barrier to infect target cells. The development of microbicides to restrain heterosexual HIV-1 transmission in the past two decades has proven to be a challenging endeavor. Therefore, better understanding of the tissue environment in the female reproductive tract may assist in the development of the next generation of microbicides to prevent HIV-1 transmission. In this review, we highlight the important factors involved in the heterosexual transmission of HIV-1, provide an update on microbicides' clinical trials, and discuss how different delivery platforms and local immunity may empower the development of next generation of microbicide to block HIV-1 transmission in the female reproductive tract.

Acceptability of optical coherence tomography and abstinence requirements among women participating in microbicide safety trials

BACKGROUND

Developing effective and safe microbicides requires study procedures (e.g., technology used, abstinence requirements, and product use) that are acceptable to participants.

METHODS

Thirty women completed 4 study visits including pelvic examination, colposcopy, optical coherence tomography (OCT), and semistructured, qualitative interviews. Additional requirements included abstinence (for approximately 16 days) and twice daily vaginal product use (for 5.5 days). Interviews were audio-recorded, transcribed, and analyzed using framework analysis. Themes addressing OCT experiences, acceptability of abstinence, and vaginal product use were examined.

RESULTS

OCT was viewed favorably as an imaging technology. Some women reported feeling the fiber-optic probe "poking" them and more than one-third spontaneously reported feeling pressure or pinching upon rotation of the speculum in connection with the OCT evaluation. Compliance with vaginal gel use was high, but for many women assigned to use a product containing nonoxynol-9 (vs. placebo), the postproduct use examination was more uncomfortable, relative to the initial examination or 1 week following product discontinuation. Nearly all women experienced product leakage; acceptability of leakage varied. Two women were not abstinent and several more found abstinence challenging. Some women involved their partner in decision making regarding trial enrollment. Strategies to remain abstinent included participating when the partner was away, avoiding early intimacy, and engaging in alternative sexual activities.

CONCLUSIONS

Qualitative interviews in early-phase studies provide insights and capture information that would be missed by behavioral inference alone. Understanding participant's experiences is important in order to provide anticipatory guidance and plan future microbicide studies that facilitate adherence with trial requirements.

Topical microbicides and HIV prevention in the female genital tract

Worldwide, HIV disproportionately affects women who are often unable to negotiate traditional HIV preventive strategies such as condoms. In the absence of an effective vaccine or cure, chemoprophylaxis may be a valuable self-initiated alternative. Topical microbicides have been investigated as one such option. The first generation topical microbicides were non-specific, broad-spectrum antimicrobial agents, including surfactants, polyanions, and acid buffering gels, that generally exhibited contraceptive properties. After extensive clinical study, none prevented HIV infection, and their development was abandoned. Second generation topical microbicides include agents with selective mechanisms of antiviral activity. Most are currently being used for, or have previously been explored as, drugs for treatment of HIV. The most advanced of these is tenofovir 1% gel: the first topical agent shown to significantly reduce HIV infection by 39% compared to placebo. This review summarizes the evolution of topical microbicides for HIV chemoprophylaxis, highlights important concepts learned, and offers current and future considerations for this area of research.

Retrocyclin RC-101 blocks HIV-1 transmission across cervical mucosa in an organ culture

BACKGROUND

Cervical tissue-based organ cultures have been used successfully to evaluate microbicides for toxicity and antiviral activity. The antimicrobial peptide retrocyclin RC-101 has been shown to have potent anti-HIV activity in cell culture.

OBJECTIVE

To evaluate RC-101 in organ culture for toxicity and its ability to block HIV-1 transmission across cervical mucosa.

METHODS

A cervical tissue-based organ culture was used to measure antiviral activity of RC-101. Cytotoxicity in tissues was determined by immunostaining of cellular proteins and by measuring inflammatory cytokines using real-time reverse transcriptase-polymerase chain reaction and Luminex technology.

RESULTS

RC-101 blocked transmission of both R5 and X4 HIV-1 across cervical mucosa in this organ culture model. Furthermore, film-formulated RC-101 exhibited potent antiviral activity in organ culture. Such antiviral activity of RC-101 was retained in the presence of semen and vaginal fluid. RC-101 showed no cytotoxicity in cervical tissue. Furthermore, RC-101 did not induce proinflammatory cytokine response in tissues. RC-101 also did not have any effect on natural killer cell activity and proliferation of CD4 and CD8 cells and did not show chemotactic activity.

CONCLUSIONS

Therefore, because of strong antiviral activity and low cytotoxicity in cervical tissues, RC-101 should be considered as an excellent microbicide candidate against HIV-1.

Decreased cervical epithelial sensitivity to nonoxynol-9 (N-9) after four daily applications in a murine model of topical vaginal microbicide safety

BACKGROUND

The disappointing clinical failures of five topical vaginal microbicides have provided new insights into factors that impact microbicide safety and efficacy. Specifically, the greater risk for human immunodeficiency virus type 1 (HIV-1) acquisition associated with multiple uses of a nonoxynol-9 (N-9)-containing product has highlighted the importance of application frequency as a variable during pre-clinical microbicide development, particularly in animal model studies.

METHODS

To evaluate an association between application frequency and N-9 toxicity, experiments were performed using a mouse model of cervicovaginal microbicide safety. In this model system, changes in cervical and vaginal epithelial integrity, cytokine release, and immune cell infiltration were assessed after single and multiple exposures to N-9.

RESULTS

After the initial application of N-9 (aqueous, 1%), considerable damage to the cervical epithelium (but not the vaginal epithelium) was observed as early as 10 min post-exposure and up to 8 h post-exposure. Subsequent daily exposures (up to 4 days) were characterized by diminished cervical toxicity relative to single exposures of like duration. Levels of pro-inflammatory cytokines released into the cervicovaginal lumen and the degree of CD14-positive immune cell infiltration proximal to the cervical epithelium were also dependent on the number of N-9 exposures.

CONCLUSIONS

Rather than causing cumulative cervical epithelial damage, repeated applications of N-9 were characterized by decreased sensitivity to N-9-associated toxicity and lower levels of immune cell recruitment. These results provide new insights into the failure of N-9-based microbicides and illustrate the importance of considering multiple exposure protocols in pre-clinical microbicide development strategies.

Vaginal irritation models: the current status of available alternative and in vitro tests

Mucosal surfaces, such as the vaginal epithelium, are natural barriers to infection that are constantly exposed to bacteria and viruses, and are therefore potential sites of entry for numerous pathogens. The vaginal epithelium can be damaged mechanically, e.g. by the incorrect use of objects such as tampons, and by chemicals that are irritating or corrosive. Consequently, this can lead to an increase in susceptibility to further damage or infection. Pharmaceutical, cosmetic and personal care products that are specifically formulated for application onto human external mucosae can occasionally induce undesirable local or systemic side-effects. Therefore, the compatibility of applied materials with this mucosal surface represents a key issue to be addressed by manufacturers. The most frequently used method for assessing vaginal mucosal irritation is the in vivo rabbit vaginal irritation test. However, the current emphasis in the field of toxicology is to use alternative in vitro methods that reduce, refine, and replace the use of animals, and which model and predict human, not animal, responses. Such an approach is of particular interest to the personal care and cosmetic industries in their effort to comply with European legislative measures, such as the 7th Amendment to the EU Cosmetics Directive that does not permit the marketing of cosmetic products if they, or their ingredients, have been tested for irritation responses in animals. The focus of this review is to provide an overview of the alternative and in vitro tests that are currently available for vaginal mucosal irritation assessment, and which are already used, or may become useful, to establish the safety of newly-designed products for human use.

Mucosal integrity and inflammatory markers in the female lower genital tract as potential screening tools for vaginal microbicides

BACKGROUND

In the female genital tract, vaginal colposcopy, endometrial mucosal integrity and inflammatory mediators are potential in vivo biomarkers of microbicide and contraceptive safety.

STUDY DESIGN

A randomized, blinded crossover trial of 18 subjects comparing effects of nonoxynol-9 vaginal gel (Gynol II; putative inflammatory gel), hydroxyethyl cellulose gel (HEC; putative inert gel) and no gel exposure on endometrial and vaginal epithelial integrity and endometrial and vaginal inflammatory markers [interleukin (IL) 1β, IL-6, IL-8, MCP-1, MIP-1α, MIP-1β, RANTES, tumor necrosis factor α, IL-1RA, IL-10, SLPI).

RESULTS

Gynol II was associated with more vaginal lesions. No endometrial disruptions were observed across conditions. In the vagina, RANTES (p=.055) and IL-6 (p=.04) were higher after HEC exposure than at baseline. In the endometrium, IL-1β (p=.003) and IL-8 (p=.025) were lower after Gynol II cycles than after no gel.

CONCLUSIONS

Gynol II and HEC may modulate inflammatory markers in the vagina and endometrium. How these changes relate to infection susceptibility warrants further study.

Development of an in vitro alternative assay method for vaginal irritation

The vaginal mucosa is commonly exposed to chemicals and therapeutic agents that may result in irritation and/or inflammation. In addition to acute effects, vaginal irritation and inflammation can make women more susceptible to infections such as HIV-1 and herpes simplex virus 2 (HSV-2). Hence, the vaginal irritation potential of feminine care formulations and vaginally administered therapeutic agents is a significant public health concern. Traditionally, testing of such materials has been performed using the rabbit vaginal irritation (RVI) assay. In the current study, we investigated whether the organotypic, highly differentiated EpiVaginal™ tissue could be used as a non-animal alternative to the RVI test. The EpiVaginal tissue was exposed to a single application of ingredients commonly found in feminine hygiene products and the effects on tissue viability (MTT assay), barrier disruption (measured by transepithelial electrical resistance, TEER and sodium fluorescein (NaFl) leakage), and inflammatory cytokine release (interleukin (IL)-1α, IL-1β, IL-6, and IL-8) patterns were examined. When compared to untreated controls, two irritating ingredients, nonoxynol 9 and benzalkonium chloride, reduced tissue viability to <40% and TEER to <60% while increasing NaFl leakage by 11-24% and IL-1α and IL-1β release by >100%. Four other non-irritating materials had minimal effects on these parameters. Assay reproducibility was confirmed by testing the chemicals using three different tissue production lots and by using tissues reconstructed from cells obtained from three different donors. Coefficients of variation between tissue lots reconstructed with cells obtained from the same donor or lots reconstructed with cells obtained from different donors were less than 10% and 12%, respectively. In conclusion, decreases in tissue viability and barrier function and increases in IL-1α and IL-1β release appear to be useful endpoints for preclinical screening of topically applied chemicals and formulations for their vaginal irritation potential.

Novel topical microbicides through combinatorial strategies

Purpose

Developing microbicides for topical epithelial applications is extremely challenging, as evidenced by the scarcity of approved products even after decades of research. Chemical enhancers, including surfactants, are known to be effective antimicrobial agents but are typically toxic towards epithelial cells. Here, we report on the discovery of unique surfactant formulations with improved safety and efficacy profile for epithelial applications, via a combination of high throughput screening techniques.

Methods

Over three-hundred formulations derived from nine surfactants were screened for antibacterial properties against E. coli in vitro. A subset of these formulations showed high antibacterial activity and was screened for cytotoxicity in vitro. Formulations showing high antibacterial activity and reduced cytotoxicity compared to their individual components were tested for efficacy against B. thailendensis, a model for melioidosis-causing B. pseudomallei.

Results

Lead formulations showed lower toxicity towards epidermal keratinocytes, with LC₅₀ values up to 3.5-fold higher than their component surfactants, while maintaining antibacterial efficacy against B. thailendensis.

Conclusions

Our results demonstrate that such a combinatorial screening approach can be used for designing safe and potent microbicides for epithelial applications.

A potential anti-implantation and spermicidal strategy: Putative derivatives of nonoxynol-9 and anti-inflammatory agents and their spermicidal activity

OBJECTIVES

We report the synthesis of novel ester derivatives of nonoxynol-9, an approved spermicidal agent, using the non-steroidal inflammatory drugs (NSAIDs) ibuprofen and indomethacin. Indomethacin has previously been shown to inhibit the implantation of the fertilised ovum into the uterus wall of pregnant rats. It is proposed that nonoxynol-9, in combination with a non-selective NSAID may exhibit both anti-implantation and spermicidal properties.

METHODS

Both novel derivatives and nonoxynol-9 were then tested on boar spermatozoa in order to establish if spermicidal activity was retained following the esterification.

RESULTS

The results showed that both the ibuprofen and indomethacin derivatives enabled complete cell death of boar spermatozoa at a concentration of 100 microg ml(-1), which is comparable to nonoxynol-9 at the same concentration.

CONCLUSIONS

These results indicate that NSAID derivatives of nonoxynol-9 retain the activity of the parent molecule and may have other advantages associated with the molecular incorporation of the NSAID moieties and their anti-implantation activity.

The safety of candidate vaginal microbicides since nonoxynol-9: a systematic review of published studies

OBJECTIVE

To gain a greater understanding of published safety data for candidate vaginal microbicides.

DESIGN

A systematic review of human safety trials of candidate vaginal microbicides - agents designed to protect women against HIV and other sexually transmitted infections.

METHODS

Trials were published in peer-reviewed journals, and publication cut-off was August week 4, 2008. Trials of nonoxynol-9 were excluded, as were trials without a control group, trials that enrolled only male participants or reported on the investigation of a product for the treatment of a genital infection.

RESULTS

Twenty-one trials of 11 products, involving 1465 women, satisfied review criteria. Most trials reported on genital epithelial findings and urogenital symptoms and a number reported a range of other local and systemic toxicity endpoints. Trials were generally of short duration (2 weeks or less) with small sample sizes. There were few findings of significant difference between women in active and control arms. Among the products assessed in more than one study, there were significantly more genital findings with intact epithelium in recipients of PRO2000 [relative risk (RR) 1.68, 95% confidence interval (CI) 1.08-2.60] and a lower incidence of bacterial vaginosis in dextrin sulphate recipients (RR 0.61, 95% CI 0.42-0.88). CIs were generally very wide, and most studies were unable to exclude differences of a substantial magnitude between treated and control women.

CONCLUSION

Larger and longer safety studies are necessary to detect clinically important toxicities, including those that indicate a potential increase in HIV risk, and provide assurance that agents are ready for large-scale effectiveness trials.

Heterosexual spread of HIV infection

Sexual transmission is the most common route of spread of human immunodeficiency virus (HIV), with heterosexual transmission of HIV infection accounting for 90% of those infected in 1992 and over 75% of the 10–12 million of those infected to date worldwide. Yet, heterosexual transmission is poorly understood. Since HIV can be transmitted from HIV-infected people who are asymptomatic as well as from those who have the acquired immunodeficiency syndrome (AIDS), we must better define the potential for transmission of HIV from HIV-infected individuals as well as the factors which influence the susceptibility of HIV-uninfected individuals.

Safety analysis of the diaphragm in combination with lubricant or acidifying microbicide gels: effects on markers of inflammation and innate immunity in cervicovaginal fluid

OBJECTIVE

Diaphragms are being considered for use with vaginal microbicide gels to provide enhanced protection against sexually transmitted pathogens. The purpose of this study was to determine whether use of a diaphragm with microbicide or placebo gel causes cervicovaginal inflammation or perturbations in cervicovaginal immune defense.

METHOD OF STUDY

Eighty-one non-pregnant women were randomized into three groups and instructed to use Milex (CooperSurgical, Inc., Trumbull, CT, USA)diaphragms overnight for 14 days in combination with one of the two acid-buffering microbicide gels [ACIDFORM (Instead Inc., La Jolla, CA, USA) or BufferGel(trade mark) (BG; ReProtect Inc., Baltimore, Maryland)] or placebo gel (K-Y Jelly); Personal Products Inc., Raritan, NJ, USA). Cervicovaginal lavages (CVLs) were performed prior to study entry and on days 8 and 16. Nine soluble mediators of vaginal inflammation or immune defense were measured in CVLs by Bio-Plex or ELISA.

RESULTS

Use of diaphragms with placebo or microbicide gel was not associated with increased levels of inflammation markers. Concentrations of secretory leukocyte protease inhibitor (SLPI) were markedly reduced in the BG group.

CONCLUSION

Daily use of a diaphragm with placebo or acidifying microbicide gel did not cause cervicovaginal inflammation. However, diaphragm/BG use was associated with markedly reduced levels of SLPI, an important mediator of innate immune defense. Further studies are warranted to establish the safety of diaphragm/microbicide gel combinations.

Evaluation of local tolerance of the antiretroviral spermicide (WHI-07)-loaded gel-microemulsion in the porcine female reproductive tract

The local tolerance of the antiretroviral spermicide, WHI-07 (5-bromo-6-methoxy-5,6-dihydro-3'-azidothymidine-5'-(p-bromophenyl)-methoxyalaninyl phosphate)-loaded gel-microemulsion was evaluated in a physiologically relevant and sensitive porcine model. Gilts (Duroc) in nonestrus stages of the reproductive cycle received either a single or a daily intravaginal application of 2.0% WHI-07 via a gel-microemulsion for 6 days. Cervicovaginal lavage (CVL) fluid was obtained for up to 72 h after a single exposure and the cellular profile and levels of inflammatory cytokines (IL-1beta, IL-8, IFN-gamma and TNF-alpha) were quantitated by flow cytometry and chemiluminescence-based multiplex immunoassay, respectively. The reproductive tract (vagina, cervix, uteri and Fallopian tubes) harvested on day 7 was scored histologically for evidence of mucosal irritation using a new scoring criterion for ten histological endpoints that reflect pathological changes in the epithelial/ subepithelial and vascular/perivascular compartments. When compared with irritant reactions caused by the detergent-type spermicide, benzalkonium chloride (BZK), the scatter profile of CVL immune cells and basal levels of proinflammatory cytokines (IL-1beta, IL-8, IFN-gamma and TNF-alpha) in CVL fluid were unaffected by intravaginal exposure to 2% WHI-07. Unlike BZK, endpoint histology of the proximal and distal regions of the reproductive tract from gilts treated with 2.0% WHI-07 via gel-microemulsion for 6 days did not result in mucosal irritation or alteration in the epithelium, subepithelium/lamina propria, vessels/perivascular tissues and underlying/surrounding muscles. Based on surrogate markers for inflammation, leukocyte profile and histologic data for local tolerance, repeated intravaginal administration of WHI-07 via gel-microemulsion as a prophylactic contraceptive is unlikely to cause vaginal irritation.

Preclinical evaluation of a dual-acting microbicidal prodrug WHI-07 in combination with vanadocene dithiocarbamate in the female reproductive tract of rabbit, pig, and cat

The mucosal safety of the combination antiretroviral spermicide,WHI-07 [5-bromo-6-methoxy-5,6-dihydro-3'-azidothymidine-5'-(p-bromophenyl)-methoxy alaninyl phosphate] and vanadocene dithiocarbamate (VDDTC), was evaluated in 3 different animal models. Twenty-seven NZW rabbits in four subgroups were exposed intravaginally to a gel-microemulsion (GM) with and without three dose levels of WHI-07 plus VDDTC (0.5+0.06%, 1.0+0.12% and 2.0+0.25%) or 4% nonoxynol-9 (N-9; Conceptrol) for 14 consecutive days. Ten nonestrus gilts (Duroc) in three subgroups received either a single or daily intravaginal application of GM with and without 2.0% WHI-07 plus 0.25% VDDTC or 2.0% benzalkonium chloride (BZK)-containing gel for 6 and 4 consecutive days, respectively. Five cats received a single intravaginal application of GM incorporating 2.0% WHI-07 plus 0.25% VDDTC. Genital tract histopathology was performed in the pig and rabbit at the end of dosing period but after 18 weeks post-dosing in the cat. Porcine cervicovaginal lavage (CVL) fluid was obtained for up to 72 hours after a single exposure and changes in the levels of inflammatory cytokines (IL-1beta, IL-8, IFN-gamma, and TNF-alpha) were quantitated by a multiplexed chemiluminescence-based immunoassay. Rabbit vaginal tissues were evaluated for localized cellular inflammation and in situ apoptosis by immunohistochemical staining for CD45, nuclear factor (NF)-kappa B, and terminal deoxynucleotidyl transferase-mediated FITC-deoxyuridine triphosphate nick-end labeling (TUNEL) using confocal laser scanning microscopy (CLSM), respectively. Vanadium content in selected organs and body fluids from rabbits and pigs was determined by atomic absorption spectroscopy. When compared with 4% N-9 (total irritation score 13-14 out of a possible 16), none of the rabbits given WHI-07 plus VDDTC intravaginally, developed histological alterations such as epithelial erosion, edema, leukocyte influx or vascular congestion characteristic of inflammation (total irritation score 4-6). CD45 and NF-kappa B immunoreactivity was limited to cells within the vascular lumen of both control and WHI-07 plus VDDTC-treated vaginal tissues. TUNEL assay revealed lack of increased apoptotic cells in vaginal mucosa exposed to increasing concentrations of WHI-07 plus VDDTC. Basal levels of proinflammatory cytokines (IL-1beta, IL-8, IFN-gamma and TNF-alpha) in porcine CVL were unaffected by intravaginal exposure to WHI-07 plus VDDTC when compared with BZK used as a positive control. Endpoint histology of the reproductive tract from cats and pigs after a single or repeated intravaginal exposure to WHI-07 plus VDDTC, respectively, revealed lack of irritation/inflammation in the epithelium, subepithelium/lamina propria, vessels/perivascular tissues, and underlying/surrounding muscles. Vanadium was not preferentially incorporated into rabbit or porcine tissues and body fluids at levels above 1 microg/g. Based on comparative histologic data and surrogate markers for inflammation, repeated intravaginal administration of WHI-07 plus VDDTC via a gel-microemulsion did not result in vaginal irritation, mucosal toxicity, or systemic absorption of vanadium. Therefore, the combined use of WHI-07 and VDDTC via gel-microemulsion appears safe for topical use as a prophylactic anti-HIV microbicide.

Cervicovaginal colposcopic lesions associated with 5 nonoxynol-9 vaginal spermicide formulations

OBJECTIVE

This study was undertaken to compare the colposcopic appearance of the cervicovaginal epithelium with spermicide use vs condom use in a low-risk population.

STUDY DESIGN

This was an ancillary study of a trial comparing the efficacy of 5 nonoxynol-9 spermicides. A cohort of women who used condoms without spermicide served as a control group. Colposcopic examinations were performed during product use to identify genital lesions.

RESULTS

One hundred fifty-one participants had 1 or more follow-up examinations. At baseline, study groups differed only by the prevalence of baseline lesions. New lesions were identified at 49% of follow-up visits. Controlling for the presence of a baseline lesion, compared with condom use none of the spermicides were associated with an increase in new lesions (overall odds ratio, 0.8; 95% CI, 0.4-1.6; P = .5); and lesions characterized by epithelial disruption were less frequent with spermicide use (overall odds ratio, 0.3; 95% CI, 0.1-0.6; P < .001).

CONCLUSION

In a low-risk population, women who used nonoxynol-9 spermicides were less likely to have lesions with epithelial disruption, and equally likely to have any new lesion compared with condom use.

Subchronic (26- and 52-week) toxicity and irritation studies of a novel microbicidal gel formulation containing sodium lauryl sulfate in animal models

The safety of an ethylene oxide/propylene oxide gel formulation containing sodium lauryl sulfate (2%, w/w), that could be a potent candidate as a topical microbicide, has been evaluated. More specifically, the subchronic (26- and 52-week) toxicity of the formulation when applied intravaginally as well as its irritating potential for the rectal, penile, eye, skin and buccal mucosa have been examined in animal models. The results showed that the vaginal administration of the gel formulation containing sodium lauryl sulfate once and twice daily (with doses 12 +/- 2 h apart) for 26 weeks to rats and for 52 weeks to rabbits induced slight to moderate histopathological alterations. When the formulation was applied intrarectally to male and female rabbits once and twice daily (with doses 12 +/- 2 h apart) for 14 days, no macroscopic or microscopic changes were reported. For both vaginal and rectal dosing, no effect was seen on the haematology, coagulation and serum chemistry parameters as well as on the body weight of animals and the relative organ weights. Other sporadic macroscopic and histopathological findings were incidental in origin and of no toxicological significance. The gel formulation containing sodium lauryl sulfate was considered as mildly irritating for the penile mucosa of rabbits, non-irritating for the eye of rabbits, mildly irritating for the skin in a rabbit model and non-irritating for the hamster cheek pouch. It is suggested that the gel formulation containing sodium lauryl sulfate is safe for most tissues that could be exposed to the product under normal use.

SAVVY (C31G) gel for prevention of HIV infection in women: a Phase 3, double-blind, randomized, placebo-controlled trial in Ghana

Objective

The objective of this trial was to determine the effectiveness of 1.0% C31G (SAVVY) in preventing male-to-female vaginal transmission of HIV infection among women at high risk.

Methodology/Principal Findings

This was a Phase 3, double-blind, randomized, placebo-controlled trial. Participants made up to 12 monthly visits for HIV testing, adverse event reporting, and study product supply. The study was conducted between March 2004 and February 2006 in Accra and Kumasi, Ghana. We enrolled 2142 HIV-negative women at high risk of HIV infection, and randomized them to SAVVY or placebo gel. Main outcome measures were the incidence of HIV-1 and HIV-2 infection as determined by detection of HIV antibodies from oral mucosal transudate specimens and adverse events. We accrued 790 person-years of follow-up in the SAVVY group and 772 person-years in the placebo group. No clinically significant differences in the overall frequency of adverse events, abnormal pelvic examination findings, or abnormal laboratory results were seen between treatment groups. However, more participants in the SAVVY group reported reproductive tract adverse events than in the placebo group (13.0% versus 9.4%). Seventeen HIV seroconversions occurred; eight in participants randomized to SAVVY and nine in participants receiving placebo. The Kaplan-Meier estimates of the cumulative probability of HIV infection through 12 months were 0.010 in the SAVVY group and 0.011 in the placebo group (p = 0.731), with a hazard ratio (SAVVY versus placebo) of 0.88 (95% confidence interval 0.33, 2.27). Because of a lower-than-expected HIV incidence, we were unable to achieve the required number of HIV infections (66) to obtain the desired study power.

Conclusions/Significance

SAVVY was not associated with increased adverse events overall, but was associated with higher reporting of reproductive adverse events. Our data are insufficient to conclude whether SAVVY is effective at preventing HIV infection relative to placebo.

Trial Registration

ClinicalTrials.gov NCT00129532

Contraceptive Efficacy of a Novel Spermicidal Microbicide Used With a Diaphragm

OBJECTIVE

Women need products that protect against both pregnancy and sexually transmitted infections, including human immunodeficiency virus (HIV). The acid buffering gel is a nondetergent spermicide that may provide this dual protection by reinforcing normal vaginal acidity to inactivate both sperm and acid-sensitive sexually transmitted pathogens. The objective of this study was to assess the gel's contraceptive effects, safety, and acceptability.

METHODS

We conducted a multicenter, randomized, double-masked, noninferiority study at 11 centers, comparing 621 women who used an acid buffering gel plus diaphragm with 300 women who used a nonoxynol-9 spermicide plus diaphragm for 6 months. A double-masked study extension followed 234 women for an additional 6 months of use.

RESULTS

The 6-month pregnancy rate per hundred women was 10.1% (95% confidence interval [CI] 7.1-13.1%) for acid buffering gel and 12.3 (95% CI 7.7-16.9) for nonoxynol-9 spermicide users. The difference in rates was -2.2% with a 95% CI -7.7 to 3.3%. Consistent and correct use 6-month pregnancy rates were 4.7% for acid buffering gel and 6.1% for nonoxynol-9 spermicide users, calculated from those cycles where diary entries indicated such use. Adverse events and acceptability were similar between the two groups. Pregnancy probabilities were similar between groups participating in the 12-month study extension.

CONCLUSION

An acid buffering gel used with a diaphragm is a safe, acceptable contraceptive with efficacy comparable to that of a common commercial spermicide with diaphragm.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, www.ClinicalTrials.gov, NCT00065858

LEVEL OF EVIDENCE

I.

Impact of microbicides and sexually transmitted infections on mucosal immunity in the female genital tract

Human immunodeficiency virus, genital herpes, and other sexually transmitted infections are a critical national and global health priority requiring the rapid development of safe and effective control methods. Topical microbicides, self-administered agents designed for vaginal use, that block transmission at the mucosal surface may provide a realistic method of intervention that could be distributed worldwide. An optimal microbicide should protect against infection but must also be safe, without adversely affecting the mucosal environment, including mediators of host defense. Thus, a critical component in microbicides development is to identify optimal assays that could serve as surrogate markers to predict safety of microbicides prior to embarking on large-scale clinical trials. This will require a greater understanding of the mediators of mucosal immunity in the female genital tract.

Temperature and pH Sensitive Hydrogels: An Approach Towards Smart Semen-Triggered Vaginal Microbicidal Vehicles

Microbicides are drug delivery systems (DDSs) for the prevention of sexual transmission of HIV and other STDs. A topically applied vaginal microbicidal gel should provide uniform coating of vaginal tissue, retention of this gel layer prior to intercourse, and controlled release kinetics of antivirals to inactivate the viral load potentially introduced during sexual activity. Here, we describe the microbicide-oriented characterization of a DDS made with a dual pH sensitive and thermosensitive smart polymer gel composed of a random terpolymer of N-isopropyl acrylamide, butyl methacrylate, and acrylic acid. The system was engineered to coat vaginal tissue with a stable gel layer and to release entrapped model agents in a burst release profile in response to the presence of the infecting agent: semen. The gel rheology, layer erosion properties, model drug release kinetics, and cytocompatibility of the terpolymer system were studied. Negligible erosion of the gel in the presence of vaginal fluid simulant suggests prolonged retention. Burst release of molecular and macromolecular model compounds was observed when the system's pH changed from the vaginal pH to the pH of semen, and cytotoxicity studies showed that the terpolymer is equally cytocompatible as a commonly used polymeric vaginal carrier.

Development of a new methodology for screening of human immunodeficiency virus type 1 microbicides based on real-time PCR quantification

Potential topical retrovirucides or vaginal microbicides against human immunodeficiency virus type 1 (HIV-1) include nonnucleoside reverse transcriptase inhibitors (NNRTIs). To be successful, such agents have to be highly active against cell-free virions. In the present study, we developed a new real-time PCR-based assay to measure the natural endogenous reverse transcription (NERT) activity directly on intact HIV-1 particles in the presence of reverse transcriptase (RT) inhibitors. We further evaluated the permeability to nevirapine (NVP) and efavirenz (EFV) and their retention within nascent viral particles. We also demonstrated the NVP and EFV inhibitory effects on NERT activity and the impact of resistance mutations measured directly by this new strategy. Furthermore, the results showed a clear correlation between NERT activity and classical infectivity assays. The 50% inhibitory concentrations (IC50s) of NVP and EFV were demonstrated to be up to 100-fold higher for cell-free than for cell-associated virions, suggesting that cell-free virions are less permeable to these drugs. Our results suggest that NVP and EFV penetrate both the envelope and the capsid of HIV-1 particles and readily inactivate cell-free virions. However, the characteristics of these NNRTIs, such as lower permeability and lower retention during washing procedures, in cell-free virions reduce their efficacies as microbicides. Here, we demonstrate the usefulness of the NERT real-time PCR as an assay for screening novel antiretroviral compounds with unique mechanisms of action.

Safety and Acceptability of the Candidate Microbicide Carraguard in Thai Women

OBJECTIVE

To determine the safety and acceptability of vaginal application of Carraguard, a carrageenan-derived candidate microbicide gel.

DESIGN

A randomized, placebo-controlled, triple-blinded clinical trial was conducted in Chiang Rai, northern Thailand.

METHODS

Women were asked to insert one applicator of study gel vaginally at least three times per week (with or without sex) and to use gel with condoms every time they had sex. Safety was assessed by visual inspection of the vagina and cervix, changes in vaginal flora and self-reported symptoms at day 14, month 1 and then monthly for up to 1 year. Acceptability was assessed through reported use of the gel, return of used and unused applicators, and quarterly interviews.

RESULTS

One hundred sixty-five women were randomized: 83 to Carraguard and 82 to the placebo (methylcellulose gel) group. Study gel use was similarly high in both groups throughout the trial with an average of four applicators per week. Carraguard use was not associated with abnormal genital clinical findings, abnormal vaginal flora, Pap smear abnormalities or other abnormal clinical signs or symptoms. Adverse events were mostly mild, not attributed to gel use, and similarly distributed between groups. Participants in both groups reported high acceptability.

CONCLUSIONS

Carraguard can safely be used an average of four times per week with or without sex and is acceptable to Thai women. A Phase III efficacy trial of Carraguard is warranted and is currently ongoing in South Africa.

Colposcopically obtained images of vulvar, vaginal, and cervical epithelium for assessment of safety of intravaginal agents among normal adolescent females: comparison with in vivo exam and interobserver agreement

OBJECTIVES

This study was designed to assess identification of epithelial abnormalities of both in vivo examination as compared with colposcopically obtained images and interobserver assessment of the same images of the lower genital tract in healthy women.

MATERIALS AND METHODS

Ninety women between the ages of 14 and 21 years were recruited for a phase II trial of a vaginal Lactobacillus crispatus capsule. All women underwent a baseline and 1-week colposcopic examination. Multiple genital tract areas were evaluated for abnormalities and photographed. The original examiner and two experienced colposcopists reevaluated all images masked to previous interpretations. Agreement was evaluated using kappa statistics.

RESULTS

The representative kappa statistics for direct observation vs photographic interpretation for the vulva, vagina, and cervix are: 37%, -2%, and -4%, respectively. The kappa statistics comparing the three observers ranged from 1% to 39%. CONCLUSIONS.: There is poor agreement between in vivo exams and photographic interpretation, and interobserver assessments of lower genital tract photographs.

Preclinical evaluation of synthetic -2 RANTES as a candidate vaginal microbicide to target CCR5

A potential strategy that can be used to combat the worldwide AIDS epidemic is the development of a vaginal microbicide that prevents the sexual transmission of human immunodeficiency virus type 1 (HIV-1). Certain CC chemokines, including RANTES, MIP-1alpha, and MIP-1beta, might facilitate the development of such microbicides since they potently suppress HIV-1 infection by binding to CCR5, the viral coreceptor used by most sexually transmitted strains of HIV-1 to enter host cells. In this study, we evaluated whether a CCR5-specific fragment of RANTES that lacks two N-terminal residues (-2 RANTES) and possesses especially potent HIV-1 suppressive activity has toxicity profiles conducive to the advancement of testing in candidate microbicide formulations. Analyses were carried out with a synthetic version of the chemokine, which was formulated with either Novasomes 7474, a nonphospholipid liposome, or methylcellulose gel. Dialysis studies demonstrated that the formulated -2 RANTES was released from both vehicles and retained anti-HIV-1 activity. Preclinical toxicity studies carried out with Swiss Webster mouse and New Zealand White rabbit vaginal irritation models demonstrated minimal inflammation and minimal adverse changes in cervicovaginal tissue integrity after short-term (10 min) and long-term (24 h) exposure to formulations containing up to 1 mg/ml of -2 RANTES. Similarly, no toxicity was observed with formulations of bioactive murine RANTES in the Swiss Webster mouse vaginal irritation model. Overall, these preclinical studies suggest that -2 RANTES is suitable for further testing as a candidate anti-HIV-1 microbicide.

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.

Extragenital manifestations of Neisseria gonorrhoeae

Neisseria gonorrhoeae is a common cause of genitourinary sexually transmitted infections. N. gonorrhoeae is an obligate human pathogen that has evidence of tissue-specific host interactions and diverse extragenital manifestations of infection both in adult and pediatric populations. The clinical presentation of extragenital gonorrhea, diagnostic methods, treatment and preventive measures are reviewed.

Safety and tolerability of tenofovir vaginal gel in abstinent and sexually active HIV-infected and uninfected women

OBJECTIVES

To establish the highest practical dose and frequency (HPDF) of 0.3% or 1% tenofovir vaginal gel applied once or twice daily by sexually abstinent HIV-uninfected women, and to evaluate the safety, tolerability and systemic pharmacokinetics of the HPDF in abstinent and sexually active HIV-negative and HIV-infected women.

METHODS

Eighty-four women, enrolled in sequential cohorts, used the study product for 14 consecutive intermenstrual days. Safety laboratory assessments and pelvic examinations were carried out during five study visits, with colposcopy at enrollment and on day 14. Samples for pharmacokinetics were collected before and after the initial tenofovir gel use and at day 13.

RESULTS

The 1% tenofovir gel used twice daily was as well tolerated as other regimens used by the 48 HIV-negative sexually abstinent women, establishing the HPDF. Although 92% of the women reported at least one adverse event, the majority were mild (87%) and involved the genitourinary tract (70%). One possibly product-related severe adverse event involving lower abdominal cramping was reported by a sexually abstinent woman who used 0.3% gel twice daily. Serum tenofovir levels were low but detectable in 14 of the 25 women. No new HIV RNA resistance mutations were detected after 2 weeks of tenofovir gel in the 24 HIV-infected participants. No significant systemic toxicity was detected.

CONCLUSION

A 2-week course of 1% tenofovir vaginal gel used twice daily was well tolerated in sexually abstinent and sexually active HIV-negative and HIV-positive women. Systemic tenofovir absorption occurred. Expanded safety and effectiveness testing is warranted.

Prolonged exposure to the candidate microbicide C31G differentially reduces cellular sensitivity to agent re-exposure

Comparative assays of in vitro cytotoxicity using nonoxynol-9 (N-9) and the candidate microbicides C31G and sodium dodecyl sulfate (SDS) demonstrated that these agents, which are, respectively, characterized as nonionic, amphoteric, and anionic surfactants, differed in their concentration-dependent effects on cell viability, especially after prolonged exposure. We hypothesized that differences in cellular sensitivity may have been due, in part, to cellular changes induced by long-term exposure to each agent. To examine this possibility, HeLa cells were exposed to N-9, C31G, or SDS for extended periods of time and subsequently reassessed for sensitivity to each of these agents. Following 10 continuous days of C31G exposure, HeLa cells were less sensitive to a subsequent C31G exposure compared to cells that had not undergone long-term C31G treatment. Interestingly, long-term C31G exposure also changed subsequent sensitivity to N-9 but not SDS. In contrast, prolonged exposure to either N-9 or SDS did not reduce sensitivity to re-exposure. The effect of long-term C31G exposure was both concentration-dependent and transient, as treated cells reverted to pre-exposure sensitivity in a time-dependent manner following the cessation of C31G exposure. Lipid analyses of cells exposed to C31G for extended durations revealed altered phospholipid profiles relative to C31G-naïve cells. Experiments examining the individual components of C31G demonstrated the involvement of the amine oxide moiety in reductions in cellular sensitivity. These studies, which provide new information concerning the cytotoxicity of surfactant microbicides, suggest that cervicovaginal epithelial cells may have greater in vivo tolerance for products containing C31G through unique interactions between C31G and components of the cellular membranes.