A Phase 1 pharmacokinetic study of a single-dose bioadhesive clindamycin 2% gel for bacterial vaginosis.

OBJECTIVES: To evaluate pharmacokinetics (PK) of a single dose of an investigational 2% clindamycin phosphate vaginal gel in healthy women by assessment of plasma and vaginal clindamycin concentrations over 7 days, and assess safety. METHODS: Single-centre, Phase 1, single-dose PK study. Blood and vaginal samples were collected daily and safety was evaluated through to Day 7. RESULTS: Twenty-one subjects were enrolled; 20 completed the study. Plasma clindamycin concentrations demonstrated quantifiable values in all subjects through to 24 h post-dose, remaining above the limits of quantification (LOQ) through to 48 h for the majority of subjects. Systemic exposure (AUC0-t) was 1179 (range 62-3822) h·ng/mL. Arithmetic mean AUC0-24 was 818 (range 51-3287) h·ng/mL. Vaginal clindamycin phosphate levels were relatively high 24 h following administration in 15/21 subjects (6 subjects had values >400 µg/g and 9 had values of 100-400 µg/g). The levels dropped in most participants to below the LOQ 2 days following dosing. In a few participants, levels remained elevated for several days. Maximal amounts of vaginal clindamycin occurred on Day 2 with a mean value of 30.3 µg. One treatment-emergent adverse event (TEAE) of moderate-severity headache not related to study drug was reported and resolved on Day 1. No TEAEs were related to physical examinations, pelvic examinations, laboratory values or vital signs. CONCLUSIONS: The vaginal concentrations of clindamycin phosphate plus the clindamycin plasma profile over time are consistent with release of drug from the investigational gel over 24 to 72 h. A single dose was well tolerated.

Pharmacokinetic and safety analyses of tenofovir and tenofovir-emtricitabine vaginal tablets in pigtailed macaques.

Vaginal rapidly disintegrating tablets (RDTs) containing tenofovir (TFV) or TFV and emtricitabine (FTC) were evaluated for safety and pharmacokinetics in pigtailed macaques. Two separate animal groups (n = 4) received TFV (10 mg) or TFV-FTC (10 mg each) RDTs, administered near the cervix. A third group (n = 4) received 1 ml TFV gel. Blood plasma, vaginal tissue biopsy specimens, and vaginal fluids were collected before and after product application at 0, 0.5, 1, 4, and 24 h. A disintegration time of <30 min following vaginal application of the RDTs was noted, with negligible effects on local inflammatory cytokines, vaginal pH, and microflora. TFV pharmacokinetics were generally similar for both RDTs and gel, with peak median concentrations in vaginal tissues and vaginal secretions being on the order of 10(4) to 10(5) ng/g (147 to 571 µM) and 10(6) ng/g (12 to 34 mM), respectively, at 1 to 4 h postdose. At 24 h, however, TFV vaginal tissue levels were more sustained after RDT dosing, with median TFV concentrations being approximately 1 log higher than those with gel dosing. FTC pharmacokinetics after combination RDT dosing were similar to those of TFV, with peak median vaginal tissue and fluid levels being on the order of 10(4) ng/g (374 µM) and 10(6) ng/g (32 mM), respectively, at 1 h postdose with levels in fluid remaining high at 24 h. RDTs are a promising alternative vaginal dosage form, delivering TFV and/or FTC at levels that would be considered inhibitory to simian-human immunodeficiency virus in the macaque vaginal microenvironment over a 24-h period.

A nine-month repeat-dose intravaginal ring (Ovaprene) irritation study in sheep.

OBJECTIVES: Ovaprene is a novel, investigational, intravaginal hormone-free monthly ring contraceptive designed for use in women of reproductive age to be worn over multiple weeks (one menstrual cycle). The objective of this work was to evaluate the safety of Ovaprene during a nine-month repeat-dose sheep study. STUDY DESIGN: In addition to traditional safety endpoints such as histopathological evaluation of the sheep female reproductive tract, vaginal fluids were collected and tested for released iron over time. Also, the amount of iron in the rings was assessed following removal, and serum iron levels were measured. There were four sheep in each group (Ovaprene group and sham group). RESULTS: There were no macroscopic clinical findings. There was minimal to mild, mixed or mononuclear cell infiltration present in all levels of vagina (cranial, mid, and caudal) from all animals including sham controls based on post-study necropsy. The female reproductive tract from animals treated with the Ovaprene ring was comparable to the sham controls. The concentrations of serum iron in sheep treated with Ovaprene ring were similar compared to a sham treated animal. The average amount of ferrous gluconate released from Ovaprene over the 29-day period of use was 175 mg of the approximately 512 mg nominally loaded into the rings. CONCLUSIONS: Overall, the Ovaprene devices were well-tolerated in female sheep. IMPLICATIONS: This study should support a chronic (e.g., one year) contraceptive efficacy study in women.

Preliminary Efficacy of Topical Sildenafil Cream for the Treatment of Female Sexual Arousal Disorder: A Randomized Controlled Trial.

OBJECTIVE: To assess the efficacy of topical sildenafil cream, 3.6% among healthy premenopausal women with female sexual arousal disorder. METHODS: We conducted a phase 2b, exploratory, randomized, placebo-controlled, double-blind study of sildenafil cream. Coprimary efficacy endpoints were the change from baseline to week 12 in the Arousal Sensation domain of the SFQ28 (Sexual Function Questionnaire) and question 14 of the FSDS-DAO (Female Sexual Distress Scale-Desire, Arousal, Orgasm). RESULTS: Two hundred women with female sexual arousal disorder were randomized to sildenafil cream (n=101) or placebo cream (n=99). A total of 174 participants completed the study (sildenafil 90, placebo 84). Among the intention-to-treat (ITT) population, which included women with only female sexual arousal disorder and those with female sexual arousal disorder with concomitant sexual dysfunction diagnoses or genital pain, although the sildenafil cream group demonstrated greater improvement in the SFQ28 Arousal Sensation domain scores, there were no statistically significant differences between sildenafil and placebo cream users in the coprimary and secondary efficacy endpoints. An exploratory post hoc subset of the ITT population with an enrollment diagnosis of female sexual arousal disorder with or without concomitant decreased desire randomized to sildenafil cream reported significant increases in their SFQ28 Arousal Sensation domain score (least squares mean 2.03 [SE 0.62]) compared with placebo cream (least squares mean 0.08 [SE 0.71], P =.04). This subset achieved a larger mean improvement in the SFQ28 Desire and Orgasm domain scores. This subset population also had significantly reduced sexual distress and interpersonal difficulties with sildenafil cream use as measured by FSDS-DAO questions 3, 5, and 10 (all P ≤.04). CONCLUSION: Topical sildenafil cream improved outcomes among women with female sexual arousal disorder, most significantly in those who did not have concomitant orgasmic dysfunction. In particular, in an exploratory analysis of a subset of women with female sexual arousal disorder with or without concomitant decreased desire, topical sildenafil cream increased sexual arousal sensation, desire, and orgasm and reduced sexual distress. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov , NCT04948151.

Safety testing of Ovaprene: An investigational nonhormonal monthly vaginal contraceptive.

OBJECTIVES: Evaluate the safety of Ovaprene, an investigational nonhormonal vaginal contraceptive designed for monthly use. STUDY DESIGN: Open-label, multicenter study enrolling heterosexually-active women with previous permanent contraception who underwent assessments during five menstrual cycles: baseline postcoital test cycle, diaphragm postcoital test cycle, Ovaprene safety cycle, and two Ovaprene postcoital test cycles. Safety outcomes included treatment-emergent adverse events, systemic laboratory findings, pelvic examinations, colposcopies, Nugent scores, determination of community state types of vaginal microbiota, and anti-Escherichia coli activity and inflammatory markers in cervicovaginal fluids. RESULTS: We enrolled 38 participants. Of these, 33 used Ovaprene and completed 77 Ovaprene cycles. The most common product-related urogenital treatment-emergent adverse events were bacterial vaginosis and vaginal odor. The frequency of transitioning from Lactobacillus-dominated community state type to community state type IV (not Lactobacillus-dominated) was similar before Ovaprene use and afterwards. Mean Nugent scores were <4 at each visit without a discernible upward trend. Inflammatory markers showed wide variation but no upward trend, and E. coli inhibitory activity of cervical secretions did not change. We found no Staphylococcus aureus, the causative agent in toxic shock syndrome, on used Ovaprenes or in vaginal samples. No clinically important changes in systemic laboratory findings, pelvic examinations, or colposcopies occurred during Ovaprene use. CONCLUSIONS: Ovaprene use did not result in cervicovaginal irritation or adverse effects on resident vaginal microbiota and did not impact transitions from a Lactobacillus-dominated community state type to community state type IV. IMPLICATIONS: The finding that the use of Ovaprene, an investigational monthly user-controlled nonhormonal vaginal contraceptive, does not appear to result in adverse changes in vaginal health during short-term use supports further evaluation of the contraceptive potential of the device.

Successful postcoital testing of Ovaprene: An investigational non-hormonal monthly vaginal contraceptive.

OBJECTIVE: Evaluate reduction in progressively motile sperm per high power field (HPF) in midcycle cervical mucus after intercourse with Ovaprene: an investigational monthly non-hormonal vaginal contraceptive consisting of a vaginal ring and mechanical barrier, releasing spermiostatic ferrous gluconate. STUDY DESIGN: Open-label, multicenter study enrolling heterosexually-active women with previous permanent contraception. Participants underwent a baseline postcoital test cycle with no device to confirm the presence of sperm, followed by one diaphragm postcoital test cycle, one Ovaprene safety cycle, and two Ovaprene postcoital test cycles. In each postcoital test cycle, participants underwent a midcycle cervical mucus evaluation to confirm an Insler score ≥10 and absence of sperm, and then returned two to four hours after vaginal intercourse for repeat cervical mucus evaluation. We considered <5 progressively motile sperm/HPF indicative of preliminary contraceptive effectiveness. RESULTS: We enrolled 38 participants; 23 completed the study. All participants had ≥5 progressively motile sperm/HPF in the baseline cycle and <5 progressively motile sperm/HPF in all 49 Ovaprene cycles and all 35 diaphragm cycles, meeting the definition of a successful postcoital test. This was true regardless of examiner blinding, prior vaginal delivery or vaginal ring use, body mass index, or dislodgements noted by the participant or investigator. The mean of 27.2 (±17.9) progressively motile sperm/HPF in baseline postcoital test cycles was reduced to 0.5 (±1.1) and 0.5 (±1.3) progressively motile sperm/HPF in the first and second Ovaprene cycles, respectively. Ovaprene fit all participants and all could insert, position, and remove it. CONCLUSION: Use of Ovaprene resulted in meeting the prespecified criterion for contraceptive effect by all participants during all postcoital test cycles. IMPLICATIONS: The finding that use of Ovaprene, an investigational monthly non-hormonal vaginal contraceptive, resulted in postcoital testing of cervical mucus that met the pre-specified definition of success (<5 progressively motile sperm/HPF) supports further evaluation of contraceptive efficacy of the device in users at risk for pregnancy.

Evaluation of 28-day estradiol and progesterone vaginal rings in a phase 1 clinical pharmacokinetic study.

OBJECTIVE: The aim of this work is to develop a combination of 17ß-estradiol (E2) and progesterone (P4) in a single-dose intravaginal ring (IVR) for the treatment of vasomotor symptoms (VMS) and genitourinary syndrome of menopause while providing endometrial protection. The objective of this study was to evaluate DARE-HRT1, a 28-day IVR that continuously delivers E2 and P4, in a phase 1 clinical trial to assess its pharmacokinetics. METHODS: This was an open-label, three-arm (group) study. Thirty-two (32) healthy postmenopausal women were recruited at two Australian sites. The average age was 57.2 years (47-69 y). The first arm received one ring for 28 days designed to release E2 at a rate of 80 µg/d and P4 at 4 mg/d (80/4 IVR); the second arm received a ring releasing E2 at 160 µg/d and P4 at 8 mg/d (160/8 IVR). The third arm received oral Estrofem (1 mg E2) and Prometrium (100 mg P4) both daily for 29 days. Blood samples were taken predose then intensively over the first day (day 1) and periodically thereafter over the remaining 27 days. After removal of the rings on the morning of day 29, intensive samples were collected. Similar procedures were conducted with women enrolled in the oral group. The plasma samples were analyzed for E2, estrone (E1), and P4 using validated bioanalytical methods. RESULTS: The baseline-adjusted steady-state plasma levels of E2 and P4 from 80/4 IVR were 20.4 ± 17.1 pg/mL and 1.32 ± 0.19 ng/mL (n = 10), respectively. The baseline-adjusted steady-state plasma levels of E2 and P4 from 160/8 IVR were 30.9 ± 8.7 pg/mL and 2.08 ± 0.50 ng/mL (n = 10), respectively. The baseline-adjusted average plasma concentrations of E2 and P4 at day 29 of the oral group were 35.4 ± 11.2 pg/mL and 0.79 ± 0.72 ng/mL (n = 11), respectively. The baseline-adjusted steady state of E1 from the 80/4 IVR and the 160/8 IVR were 22.1 ± 16.6 pg/mL (n = 10) and 25.2 ± 12.3 pg/mL (n = 10), respectively. The baseline-adjusted concentration of E1 in the oral arm was 209 ± 67.7 ng/mL (n = 11). The IVR were well tolerated, and no serious adverse events were reported. CONCLUSIONS: The 80/4 IVR and 160/8 IVR gave similar steady-state concentrations of E2 as seen with drug products approved by the US Food and Drug Administration for treatment of VMS and genitourinary symptoms of menopause. The E2 concentrations of this study support the potential of DARE-HRT1, a promising new option for hormone therapy for treatment of VMS and vaginal symptoms associated with menopause.

A phase 1/2, open-label, parallel group study to evaluate the preliminary efficacy and usability DARE-HRT1 (80 µg estradiol/4 mg progesterone and 160 µg estradiol/8 mg progesterone intravaginal RinGSM) over 12 weeks in healthy postmenopausal women.

OBJECTIVES: The exploratory objectives of this study were to evaluate the usability and acceptability and to conduct a preliminary evaluation of the efficacy of DARE-HRT1. DARE-HRT1 is an intravaginal ring (IVR) that releases 17ß2-estradiol (E2) with progesterone (P4) over 28 days. It is the first combination E2 and P4 IVR being developed for the treatment of vasomotor symptoms (VMS) in healthy postmenopausal women with an intact uterus. METHODS: This was a randomized, open-label, 2-arm, parallel group study in 21 healthy postmenopausal women. Women were randomized (1:1) to either DARE-HRT1 IVR1 (E2 80 µg/d with P4 4 mg/d) or DARE-HRT1 IVR2 (E2 160 µg/d with P4 8 mg/d). They used the assigned IVR for three 28-day cycles, inserting a new IVR monthly. Preliminary genitourinary syndrome of menopause (GSM) treatment efficacy was estimated by measuring changes from baseline in vaginal pH, vaginal maturation index (VMI), and changes in the severity of GSM symptoms. Preliminary systemic VMS efficacy was measured by changes in responses to the Menopause-Specific Quality of Life (MENQOL) questionnaire. Acceptability was assessed by product experience surveys. RESULTS: Preliminary local GSM treatment efficacy was supported by significant decreases in vaginal pH and % parabasal cells, and significant increases in the overall VMI and % superficial cells for both IVR groups (all P values <0.01). Preliminary VMS efficacy was supported by significant decreases in all domains of the MENQOL questionnaire from baseline for both dosing groups (all P values <0.01). CONCLUSIONS: Data from this study support further development of DARE-HRT1 for the treatment of menopausal symptoms.

A phase 1/2, open-label, parallel group study to evaluate the safety and pharmacokinetics of DARE-HRT1 (80 µg estradiol/4 mg progesterone and 160 µg estradiol/8 mg progesterone intravaginal rings) over 12 weeks in healthy postmenopausal women.

OBJECTIVES: Primary objectives were to evaluate the safety and systemic pharmacokinetics (PK) of DARE-HRT1, an intravaginal ring (IVR), which releases 17ß2-Estradiol (E2) with progesterone (P4) for 28 days in healthy postmenopausal women. METHODS: This was a randomized, open-label, 2-arm, parallel group study in 21 healthy postmenopausal women with an intact uterus. Women were randomized (1:1) to either DARE-HRT1 IVR1 (E2 80 µg/d with P4 4 mg/d) or DARE-HRT1 IVR2 (E2 160 µg/d with P4 8 mg/d). They used the IVR for three 28-day cycles, inserting a new IVR monthly. Safety was measured by treatment emergent adverse events and changes in systemic laboratories and the endometrial bilayer width. Baseline adjusted plasma PK of E2, P4, and estrone (E1) was described. RESULTS: Both DARE-HRT1 IVR were safe. All treatment emergent adverse events were mild or moderate and were distributed similarly among IVR1 versus IVR2 users. Month 3 median maximum plasma ( Cmax ) P4 concentrations were 2.81 and 3.51 ng/mL and Cmax E2 was 42.95 and 77.27 pg/mL for IVR1 and IVR2 groups, respectively. Month 3 median steady state ( Css ) plasma P4 concentrations were 1.19 and 1.89 ng/mL, and Css E2 was 20.73 and 38.16 pg/mL for IVR1 and IVR2 users, respectively. CONCLUSIONS: Both DARE-HRT1 IVRs were safe and released E2 in systemic concentrations, which were in the low, normal premenopausal range. Systemic P4 concentrations predict endometrial protection. Data from this study support further development of DARE-HRT1 for the treatment of menopausal symptoms.

Acceptability of Single-dose Clindamycin Gel for Bacterial Vaginosis: A Randomized Controlled Trial.

PURPOSE: The goal of this study was to assess the acceptability of a single-dose bioadhesive 2% clindamycin vaginal gel for bacterial vaginosis (BV). METHODS: This double-blind, placebo-controlled, randomized study compared a new clindamycin gel with placebo gel (2:1 ratio). The primary objective was efficacy; secondary objectives were safety and acceptability. Subjects were evaluated at screening, days 7 to 14 (Day 7-14), and days 21 to 30 (test-of-cure [TOC]). An acceptability questionnaire with 9 questions was administered at the Day 7-14 visit, and a subset of questions (#7-#9) was asked again at the TOC visit. At Visit 1, subjects were provided with a daily electronic diary (e-Diary) to collect information regarding study drug administration, vaginal discharge, odor, itching, and any other treatments used. Study site staff reviewed e-Diaries at the Day 7-14 and TOC visits. FINDINGS: A total of 307 women with BV were randomized to treatment (204 to the clindamycin gel group and 103 to the placebo gel group). Most (88.3%) reported at least one previously diagnosed BV episode, and more than one half (55.4%) had experience with other vaginal treatments for BV. At the TOC visit, almost all (91.1%) of the clindamycin gel subjects described their overall experience with the study drug as "satisfied" or "very satisfied," 95.8% indicated that they would be "likely" or "very likely" to use the product again if it became available after the study and they had BV again, and 93.7% would be "likely" or "very likely" to recommend their treatment to a friend who had BV. Almost all (90.2%) clindamycin-treated subjects responded that application was "clean" or "fairly clean," as opposed to "neither clean nor messy," "fairly messy," or "messy." Although 55.4% experienced leakage in the days after application, only 26.9% of those indicated that it was bothersome. Subjects receiving clindamycin gel also reported improvement in both odor and discharge, commencing shortly after dosing and continuing through the assessment period, regardless of whether they met the critical cure criteria. IMPLICATIONS: A single dose of a new bioadhesive 2% clindamycin vaginal gel showed rapid resolution of symptoms and was highly acceptable as a treatment for bacterial vaginosis. CLINICALTRIALS: gov identifier: NCT04370548.

Characterization of UC781-tenofovir combination gel products for HIV-1 infection prevention in an ex vivo ectocervical model.

HIV continues to be a problem worldwide. Topical vaginal microbicides represent one option being evaluated to stop the spread of HIV. With drug candidates that have a specific action against HIV now being studied, it is important that, when appropriate and based on the mechanism of action, the drug permeates the tissue so that it can be delivered to specific targets which reside there. Novel formulations of the nucleotide reverse transcriptase inhibitor tenofovir (TFV) and the nonnucleoside reverse transcriptase inhibitor UC781 have been developed and evaluated here. Gels with three distinct rheological properties were prepared. The three gels released both UC781 and TFV under in vitro conditions at concentrations equal to or above the reported 50% effective concentrations (EC(50)s). The drug concentrations in ectocervical tissues were well in excess of the reported EC(50)s. The gels maintain ectocervical viability and prevent infection of ectocervical explants after a HIV-1 challenge. This study successfully demonstrates the feasibility of using this novel combination of antiretroviral agents in an aqueous gel as an HIV infection preventative.

Simultaneous delivery of tenofovir and acyclovir via an intravaginal ring.

Vaginal microbicides may play an important role in protecting women from HIV infection. A strong synergy between HSV and HIV has been observed, and epidemiological studies demonstrate that HSV infection increases the risk of HIV acquisition. Incorporation of the antiretroviral tenofovir (TFV) along with the antiherpetic acyclovir (ACV) into combination intravaginal rings (IVRs) for sustained mucosal delivery of both compounds could lead to increased microbicide product adherence and efficacy compared with conventional vaginal formulations. A novel, dual-protection "pod IVR" platform developed in-house and delivering ACV and TFV was evaluated in rabbit and sheep models. The devices were safe and exhibited sustained release of both drugs independently and at controlled rates over the 28-day studies. Daily release rates were estimated based on residual drug content of the used devices: rabbits, 343 ± 335 µg day(-1) (ACV) and 321 ± 207 µg day(-1) (TFV); sheep, 174 ± 14 µg day(-1) (ACV) and 185 ± 34 µg day(-1) (TFV). Mean drug levels in sheep vaginal samples were as follows: secretions, 5.25 ± 7.31 µg ml(-1) (ACV) and 20.6 ± 16.2 µg ml(-1) (TFV); cervicovaginal lavage fluid, 118 ± 113 ng ml(-1) (ACV) and 191 ± 125 ng ml(-1) (TFV); tissue, 173 ng g(-1) (ACV) and 93 ng g(-1) (TFV). An in vitro-in vivo correlation was established for both drugs and will allow the development of future formulations delivering target levels for prophylaxis and therapy. These data suggest that the IVR based on the pod design has potential in the prevention of transmission of HIV-1 and other sexually transmitted pathogens.

A 90-day tenofovir reservoir intravaginal ring for mucosal HIV prophylaxis.

A vaginal gel containing the antiretroviral tenofovir (TFV) recently demonstrated 39% protection against HIV infection in women. We designed and evaluated a novel reservoir TFV intravaginal ring (IVR) to potentially improve product effectiveness by providing a more controlled and sustained vaginal dose to maintain cervicovaginal concentrations. Polyurethane tubing of various hydrophilicities was filled with a high-density TFV/glycerol/water semisolid paste and then end-sealed to create IVRs. In vitro, TFV release increased with polyurethane hydrophilicity, with 35 weight percent water-swelling polyurethane IVRs achieving an approximately 10-mg/day release for 90 days with mechanical stiffness similar to that of the commercially available NuvaRing. This design was evaluated in two 90-day in vivo sheep studies for TFV pharmacokinetics and safety. Overall, TFV vaginal tissue, vaginal fluid, and plasma levels were relatively time independent over the 90-day duration at approximately 10(4) ng/g, 10(6) ng/g, and 10(1) ng/ml, respectively, near or exceeding the highest observed concentrations in a TFV 1% gel control group. TFV vaginal fluid concentrations were approximately 1,000-fold greater than levels shown to provide significant protection in women using the TFV 1% gel. There were no toxicological findings following placebo and TFV IVR treatment for 28 or 90 days, although slight to moderate increases in inflammatory infiltrates in the vaginal epithelia were observed in these animals compared to naïve animals. In summary, the controlled release of TFV from this reservoir IVR provided elevated sheep vaginal concentrations for 90 days to merit its further evaluation as an HIV prophylactic.

Reformulated tenofovir gel for use as a dual compartment microbicide.

OBJECTIVES: Coital use of 1% tenofovir gel was shown to be modestly effective at preventing HIV transmission when applied vaginally in the CAPRISA 004 trial. Because the gel is hyperosmolar, which would reduce the integrity of the epithelium and induce fluid movement into the lumen, rectal use may not be acceptable. This study evaluated the pre-clinical safety and efficacy of a reformulated (reduced osmolality) tenofovir gel product. METHODS: Reduced glycerine (RG)-tenofovir gel was compared with the original tenofovir gel for physiochemical characteristics, product safety and anti-HIV-1 activity. RESULTS: The formulations were similar in all characteristics except for osmolality and spreadability/firmness. The RG-tenofovir gel had a 73% lower osmolality, a 29.6% increase in spreadability and a 27% decrease in firmness as compared with the original tenofovir gel. When applied to epithelial cell monolayers, tenofovir gel showed a transient reduction in the transepithelial resistance while the RG-tenofovir gel did not. Both gels retained ectocervical and colorectal explant viability. However, tenofovir gel treatment resulted in epithelial stripping that was absent after RG-tenofovir gel treatment of the polarized explants. Anti-HIV-1 activity was confirmed by lack of HIV-1 infection in polarized explants treated with either gel as compared with the control explants. CONCLUSIONS: Reducing the osmolality of the tenofovir gel resulted in improved epithelial integrity, which suggests better safety upon rectal use. The improved gel safety did not compromise drug release or anti-HIV-1 activity. These data support the use of this gel as a dual compartment microbicide.

Single-Dose, Bioadhesive Clindamycin 2% Gel for Bacterial Vaginosis: A Randomized Controlled Trial.

OBJECTIVE: To assess efficacy and safety of a single-dose vaginal clindamycin gel for bacterial vaginosis treatment. METHODS: We conducted a double-blind, placebo-controlled, randomized study comparing clindamycin gel with placebo (2:1 ratio). Entry required clinical diagnosis of bacterial vaginosis, that is, all four Amsel's criteria, without other genital infections. Nugent scores of 7-10 were required for efficacy assessment, per updated 2019 U.S. Food and Drug Administration guidance. Patients were evaluated at screening, day 7-14, and day 21-30 (test of cure). Clinical cure was defined as resolution of three of four Amsel's criteria. Bacteriologic cure was defined as Nugent score lower than 4. Therapeutic cure was both clinical and bacteriologic cure. Primary outcome was clinical cure at the test-of-cure visit. Secondary endpoints were clinical cure at day 7-14, and bacteriologic and therapeutic cures at day 7-14 and test of cure. A sample size of 188 patients in the clindamycin group compared with 94 patients in the placebo group had 90% power to detect statistically significant difference (P=.05, 2-tailed). RESULTS: Participants were seen between July 9, 2020, and November 12, 2020. Of 307 randomized women, 56.0% were Black and 88.3% reported one or more previous bacterial vaginosis episodes. In the modified intention-to-treat population, 70.5% of patients in the clindamycin group and 35.6% in the placebo group achieved clinical cure at test of cure (primary outcome) (difference of 34.9, 95% CI 19.0-50.8), as did 77.5% of patients in the clindamycin group and 42.6% of patients in the placebo group in the per-protocol population (difference of 34.9, 95% CI 17.0-52.7). Statistically significant differences between groups were seen for all secondary endpoints. Clinical cure rate in patients in the clindamycin group with more than three bacterial vaginosis episodes in the prior year was 70.0%. Approximately 15% (15.3%) of patients in the clindamycin group experienced one or more treatment-emergent adverse events related to study treatment, as did 9.7% of patients in the placebo group. The most frequent treatment-related, treatment-emergent adverse event was vulvovaginal candidiasis. CONCLUSION: A new, single-dose clindamycin vaginal gel was highly effective, with excellent safety, in women disproportionately affected by bacterial vaginosis, with Nugent scores of 7-10 at study entry. FUNDING SOURCE: The study was funded by Daré Bioscience, Inc. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov, NCT04370548.

Design of a semisolid vaginal microbicide gel by relating composition to properties and performance.

PURPOSE: Develop a preclinical in vitro algorithm enabling de novo design of semisolid vaginal drug delivery gels, by using biomechanical modeling of gel spreading in the vaginal canal and empirically relating gel composition to mechanical properties and predicted performance. METHODS: Gel performance was defined through a multivariate objective function constructed from gels' mechanical properties and selected performance criteria for gel spreading within the vaginal canal. Mixture design of experiment was used to establish a semi-empirical relationship linking composition-property and property-performance relationships for gels with varying concentrations of hydroxyethylcellulose and Carbopol 974P. This permits definition of a local optimum for gel composition and volume of administration, within a defined gel composition space. RESULTS: Rheological behavior and, consequently, the value of the objective function varied broadly with composition. The algorithm indicated a 3.0 wt% HEC gel as the near optimal composition for a 3.5 mL applied volume for gels designed to spread throughout the vagina. CONCLUSIONS: The algorithm introduced herein is a novel tool that facilitates an understanding of the composition-property-performance relationship for vaginal semisolid drug delivery gels. This approach has promise as a scientific methodology for evaluation and optimization of vaginal gels prior to in vivo investigations.

Pharmaceutical development of microbicide drug products.

HIV infection rates in the developing world remain a serious problem. One potential approach to reduce infection rates is to use products known as microbicides, referred to herein as microbicide drug products (MDPs). These are drugs capable of, when administered topically to the vagina (or rectum), interfering with infection by one or more mechanisms. This review article covers the latest pharmaceutical developments in the area of microbicides dosage forms and delivery systems. These products are principally designed for use in the developing world and must therefore address cultural and societal issues generally unknown in the developed world. The first-generation microbicides evaluated clinically were principally polyanions. These drugs, administered intravaginally as gels, were found to be ineffective in preventing transmission of HIV from men to women. Second-generation drugs such as tenofovir, dapivirine, and UC781 are reverse transcriptase inhibitors developed as gels formulations and intravaginal rings (IVRs). Gels are considered coitally-related products while IVRs are coitally-independent systems designed to release the drug over a four-week period or possibly longer (up to 3 or 4 months). Other dosage forms under development include fast dissolving films, tablets/capsules, and possibly vaginal sponges. Dual protection systems are also under development. These systems include formulations capable of preventing HIV infection along with a second drug capable of preventing conception or other viral infections such as HSV.

Phase transition behaviour in yeast and bacterial populations under stress.

Non-equilibrium phase transitions from survival to extinction have recently been observed in computational models of evolutionary dynamics. Dynamical signatures predictive of population collapse have been observed in yeast populations under stress. We experimentally investigate the population response of the budding yeast Saccharomyces cerevisiae to biological stressors (temperature and salt concentration) in order to investigate the system's behaviour in the vicinity of population collapse. While both conditions lead to population decline, the dynamical characteristics of the population response differ significantly depending on the stressor. Under temperature stress, the population undergoes a sharp change with significant fluctuations within a critical temperature range, indicative of a continuous absorbing phase transition. In the case of salt stress, the response is more gradual. A similar range of response is observed with the application of various antibiotics to Escherichia coli, with a variety of patterns of decreased growth in response to antibiotic stress both within and across antibiotic classes and mechanisms of action. These findings have implications for the identification of critical tipping points for populations under environmental stress.

The Role of Volume in the Perceptibility of Topical Vaginal Formulations: User Sensory Perceptions and Experiences of Heterosexual Couples During Vaginal Sex.

Users' sensory perceptions and experiences (USPEs; perceptibility) of drug formulations can critically impact product adoption and adherence, especially when products rely on appropriate user behaviors (timing of administration, dosing measurement) for effectiveness. The use of topical gel formulations for effective antihuman immunodeficiency virus/sexually transmitted infection (HIV/STI) vaginal microbicides has been associated with messiness and other use-associated challenges, resulting in low adherence. Nonetheless, such formulations remain attractive due to good pharmacokinetics and resulting pharmacodynamics through their volume and surface contact for drug delivery into luminal fluids and mucosa. Consequently, advocates and scientists continue to pursue topical forms [semisolid (e.g., gel, suppository); solid (e.g., film)] to deliver select drugs and offer user choice in HIV/STI prevention. The current data build on previously validated USPE scales evaluating perceptibility of gels with various biophysical/rheological properties. Specifically, increased formulation parameter space adds a new set of properties inherent in quick-dissolving film. We compared film, a product adding no discernable volume to the vaginal environment, to 2 and 3.5 mL hydroxyethyl cellulose gel to consider the impact of volume on user experience. We also examined the USPE scales for evaluation of male sexual partners' experiences. The original USPE scales functioned as expected. Additionally, six new USPE scales were identified in this enhanced parameter space. Significant differences were noted between USPEs in pairwise comparisons, with largest differences between film and high-volume gel. Product developers and behavioral scientists can use these scales to design products, optimizing user experience and maximizing adherence and delivery of efficacious anti-HIV/STI pharmaceuticals. They can be extended to evaluation of additional formulations, devices, and compartments, as well as single- and multipurpose pharmaceuticals. In broader contexts, USPEs could be of value in evaluating formulations and devices to prevent/treat other diseases (e.g., ophthalmologic, dermatologic). Steadfast attention should be given to patient experience, and, where applicable, experiences of partners and/or caregivers.

Vaginal tamoxifen for treatment of vulvar and vaginal atrophy: Pharmacokinetics and local tolerance in a rabbit model over 28 days.

Vaginally delivered tamoxifen is being developed as alternative to estrogen-based therapies for the treatment of vulvar and vaginal atrophy (VVA) symptoms in subjects at high risk for breast cancer, undergoing treatment for breast cancer with aromatase inhibitors or are breast cancer survivors. Tamoxifen (1 or 20 mg) was administered intra-vaginally to female rabbits once-daily over a 28-day period to assess its pharmacokinetics, systemic exposure and local vaginal tolerance. Plasma samples were taken to assess concentrations of tamoxifen and its metabolites 4-hydroxytamoxifen and N-desmethyltamoxifen over the first day of vaginal administration and following the last dose on Day 28. In-life observations included evaluation of the vaginal region for signs of irritation. At necropsy, vaginal irritation was assessed by the method of Eckstein which reflect collective histopathological grading of four parameters within the vagina including epithelial morphology, leukocytic infiltration, congestion, and edema. Uterine effects of vaginal tamoxifen were also assessed. Plasma concentrations of tamoxifen were higher following administration of 20 mg tamoxifen compared to 1 mg tamoxifen at both Day 1 and Day 28. The metabolite 4-hydroxytamoxifen could not be detected on Day 1 and concentrations were low at Day 28 at the 1 mg tamoxifen dose. 4-Hydroxytamoxifen concentrations were low, but detectable at Day 1 and 28 following administration of 20 mg tamoxifen. The metabolite N-desmethyltamoxifen was undetectable at the 1 mg and 20 mg doses on Day 1; it remained undetectable at the 1 mg tamoxifen dose at Day 28. N-desmethyltamoxifen was detected over the first 8 h of Day 28 then fell below the quantitation limits. There was little to no vaginal or systemic accumulation of tamoxifen following once-daily dosing for 28 days. Tamoxifen accounted for more than 85% of the total systemic exposure compared to its metabolites, 4-hydroxytamoxifen, and N-desmethyltamoxifen. There was essentially no detectable vaginal irritation evident over the course of the study. At necropsy the individual Eckstein scores (maximum score of 16) of the proximal, mid, and distal vagina of females in the 1 mg and 20 mg dose groups were generally comparable in both groups and ranged from minimal to mild magnitude (1 mg dose group: ranging from 1 to 3 in the proximal vagina, 4 to 5 in the mid vagina, and 3 to 7 in the distal vagina; 20 mg dose group: ranging from 3 to 5 in the proximal vagina, 4 to 7 in the mid vagina, and 4 to 5 in the distal vagina). Overall, tamoxifen was absorbed and metabolized following vaginal administration and vaginal irritation was minimal to none at both doses.