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BACKGROUND: There are currently no Food and Drug Administration-approved treatments for female sexual arousal disorder (FSAD), which is physiologically analogous to male erectile dysfunction. AIMS: The study sought to test the systemic and local genital safety of topical sildenafil cream, 3.6% (sildenafil cream) among healthy premenopausal women with FSAD and their sexual partners over a 12-week treatment period. METHODS: This was a phase 2b, exploratory, randomized, placebo-controlled, double-blind study of sildenafil cream among healthy premenopausal women with FSAD. Safety was assessed by the frequency and incidence of treatment-emergent adverse events (TEAEs) among participants and their sexual partners. Participants recorded the incidence of TEAEs in a daily eDiary (electronic diary). Sexual partners were contacted within 72 hours of each sexual event in which investigational product was used. All participants used placebo cream for 1 month, during a single-blind run-in period, and then if eligible, were randomized 1:1 to sildenafil cream or placebo cream. Participants used their assigned investigational product over a 12-week double-blind dosing period. They attended monthly follow-up visits, in which their eDiary TEAE data were reviewed by the study staff and graded for severity and relationship to study product. OUTCOMES: The frequency and incidence of TEAEs among participants and their sexual partners. RESULTS: During the 12-week double-blind dosing period, there were 78 TEAEs reported by 29 of 99 sildenafil-assigned participants and 65 TEAEs reported by 28 of 94 placebo-assigned participants (P = .76). All TEAEs were mild or moderate in severity. The most common treatment-related TEAE among active and placebo-assigned participants was application site discomfort. There were no differences in the number of treatment-related TEAEs among sildenafil cream vs placebo cream users (P > .99). Four sildenafil cream participants and 3 placebo cream participants discontinued the study due to TEAEs involving application site discomfort (P > .99). There were 9 TEAEs reported by 7 of 91 sexual partners exposed to sildenafil cream vs 4 TEAEs reported by 4 of 84 sexual partners exposed to placebo cream (P = .54). CLINICAL IMPLICATIONS: These data support further clinical development of topical sildenafil cream for the treatment of FSAD. STRENGTHS AND LIMITATIONS: Safety was assessed among participants and their sexual partners after 1357 and 1160 sexual experiences in which sildenafil cream or placebo cream were used, respectively. The phase 2b study was powered for the primary objectives of efficacy, rather than safety. CONCLUSION: These data demonstrate that topically applied sildenafil cream was safe and well tolerated by exposed users and their sexual partners.
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BACKGROUND: Efficacy assessments in clinical trials of treatments for female sexual arousal disorder (FSAD) and other female sexual dysfunction (FSD) diagnoses rely on various patient-reported outcomes (PROs). AIMS: We sought to compare 1-month recall PRO measures among participants enrolled in a clinical trial who provided these data without (test population) vs with (control population) use of an at-home, 24-hour recall electronic diary (eDiary), capturing similar data. METHODS: Preplanned subset analysis as performed during a phase 2b, exploratory, randomized, placebo-controlled, double-blind study of sildenafil cream, 3.6% (sildenafil cream) among healthy premenopausal women with FSAD. Preliminary product efficacy was assessed via 1-month recall and 24-hour recall questionnaires. A subset of the participants, the Evaluation of Recall Subset [ERS] provided PROs via the 1-month recall instruments but did not provide data via the 24-hour recall eDiary. OUTCOMES: Responses to the 1-month recall instruments were compared among ERS (test) vs non-ERS (control) participants. Among the non-ERS population, correlations between 1-month and 24-hour recall endpoints were calculated. RESULTS: There were no significant differences in the study co-primary 1-month recall efficacy endpoints, the Arousal Sensation (AS) domain of the 28-item Sexual Function Questionnaire (SFQ28) and the Female Sexual Distress Scale - Desire, Arousal, Orgasm question 14, among ERS vs non-ERS participants during the initial 1-month no-drug run-in period or the 1-month single-blind placebo run-in period (P values > .47). Scores on these 1-month recall PROs continued to be similar after randomization for sildenafil cream (P values > .30) and placebo cream (P values > .20) assigned ERS and non-ERS participants during the 3-month double-blind dosing period. There were strong correlations between the SFQ28 AS and eDiary AS scores during the no-drug run-in (R = 0.79, P < .01) and the single-blind run-in (R = 0.73 P < .001). During the double-blind dosing period, the SFQ28 AS score continued to be highly correlated with the eDiary AS score among sildenafil cream users (R = 0.83; P < .001) and placebo cream users (R = 0.8; 2 P < .001). CLINICAL IMPLICATIONS: There was no evidence that 1-month recall PRO instruments introduce recall bias; assessing arousal sensations with 24-hour vs 1-month PRO instruments is similar and either method could be used to assess efficacy depending on study objectives. STRENGTHS AND LIMITATIONS: This preplanned subset analysis compared efficacy of PROs based on recall duration. While the subset was preplanned, the study was powered to detect significant differences in the primary efficacy objectives, not among this subset analyses. CONCLUSION: These data will be used in planning future efficacy assessments of sildenafil cream for FSAD. CLINICAL TRIAL REGISTRATION: This clinical trial was registered with ClinicalTrials.gov, NCT04948151.
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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.
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Disfunções Sexuais Psicogênicas , Citrato de Sildenafila , Humanos , Feminino , Citrato de Sildenafila/administração & dosagem , Citrato de Sildenafila/uso terapêutico , Adulto , Método Duplo-Cego , Disfunções Sexuais Psicogênicas/tratamento farmacológico , Resultado do Tratamento , Pessoa de Meia-Idade , Administração Tópica , Disfunções Sexuais Fisiológicas/tratamento farmacológico , Adulto Jovem , Inibidores da Fosfodiesterase 5/administração & dosagem , Excitação Sexual , Inquéritos e QuestionáriosRESUMO
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.
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Dispositivos Anticoncepcionais Femininos , Vagina , Feminino , Humanos , Animais , Ovinos , Ciclo Menstrual , Anticoncepcionais , Ferro , Administração IntravaginalRESUMO
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.
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Dispositivos Anticoncepcionais Femininos , Progesterona , Feminino , Humanos , Pessoa de Meia-Idade , Austrália , Estradiol , EstronaRESUMO
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 7â 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 24â h post-dose, remaining above the limits of quantification (LOQ) through to 48â h for the majority of subjects. Systemic exposure (AUC0-t) was 1179 (range 62-3822)â h·ng/mL. Arithmetic mean AUC0-24 was 818 (range 51-3287)â h·ng/mL. Vaginal clindamycin phosphate levels were relatively high 24â h following administration in 15/21 subjects (6 subjects had values >400â µg/g and 9 had values of 100-400â µg/g). The levels dropped in most participants to below the LOQ 2â 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 30.3â 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 72â h. A single dose was well tolerated.
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Clindamicina , Vaginose Bacteriana , Humanos , Feminino , Clindamicina/efeitos adversos , Vaginose Bacteriana/tratamento farmacológico , Vaginose Bacteriana/induzido quimicamente , Área Sob a Curva , Administração OralRESUMO
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 20â¯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 20â¯mg tamoxifen compared to 1â¯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 1â¯mg tamoxifen dose. 4-Hydroxytamoxifen concentrations were low, but detectable at Day 1 and 28 following administration of 20â¯mg tamoxifen. The metabolite N-desmethyltamoxifen was undetectable at the 1â¯mg and 20â¯mg doses on Day 1; it remained undetectable at the 1â¯mg tamoxifen dose at Day 28. N-desmethyltamoxifen was detected over the first 8â¯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 28â¯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 1â¯mg and 20â¯mg dose groups were generally comparable in both groups and ranged from minimal to mild magnitude (1â¯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; 20â¯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.
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Atrofia/tratamento farmacológico , Tamoxifeno/administração & dosagem , Vagina/efeitos dos fármacos , Administração Intravaginal , Animais , Neoplasias da Mama/tratamento farmacológico , Feminino , Coelhos , Tamoxifeno/análogos & derivados , Tamoxifeno/metabolismoRESUMO
The objectives of this work were to evaluate the in vitro release and in vivo pharmacokinetics and local tolerability of a novel, segmented ethylene-vinyl acetate (EVA) intravaginal ring (IVR) delivering progesterone (P) in drug-naïve ovariectomized female Dorset crossbred sheep. Following preparation and assessment of in vitro release of P, animals were randomized into one of six treatment groups: group 1 Crinone® 8% gel (90 mg); group 2 Prometrium® 200-mg capsules; group 3 placebo IVR; group 4 progesterone (P) IVR 4 mg/day; group 5 P IVR 8 mg/day; or group 6 P IVR 12 mg/day. Crinone 8% gel and Prometrium capsules were administered once daily for 28 days. IVRs were inserted vaginally on day 1 and remained in place through day 14; a new ring was administered on day 15 and was removed at day 28. Animals underwent daily examinations to confirm ring placement, and vaginal irritation was scored from 0 (none) to 4 (severe). Blood samples were taken at scheduled times for pharmacokinetic analysis. Postmortem examinations performed on all IVR groups included vaginal irritation, macroscopic, and microscopic evaluations, including irritation scoring and histopathology. Intravaginal rings were retained over 28 days in all animals. Clinical observations showed no significant abnormal findings in any group. Pharmacokinetic analysis in animals showed sustained release of P over from days 0 through 14 of ring use. Irritation scores and microscopic assessments were consistent with the IVRs being well tolerated. These results will guide future human clinical studies to ultimately develop an IVR for use in women for the prevention of preterm birth.
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Dispositivos Anticoncepcionais Femininos , Sistemas de Liberação de Medicamentos , Progesterona/administração & dosagem , Administração Intravaginal , Animais , Liberação Controlada de Fármacos , Feminino , Progesterona/análogos & derivados , Progesterona/sangue , Progesterona/química , Progesterona/farmacocinética , Ovinos , Vagina/metabolismoRESUMO
This study reports the preparation, in vitro release, pharmacokinetics, and local tolerability of novel ethylene-vinyl acetate intravaginal rings (IVRs) delivering 17ß-estradiol (E2) and progesterone (P), in drug-naïve ovariectomized female Dorset crossbred sheep. After preparation and assessment of in vitro release of E2 and P, animals were randomized to treatment groups 1 or 2 (comparator rings releasing 50 or 100 µg/d E2, respectively), groups 3 or 4 (ethylene-vinyl acetate IVRs, 160 µg/d E2 with 4 [160/4 IVR] or 8 mg/d P [160/8 IVR], respectively), or group 5 (160 µg E2 and 10 mg P administered intravenously). IVRs were placed on day 1 and remained in place through day 29. Animals underwent daily examinations to confirm ring placement, and vaginal irritation was scored from 0 (none) to 4 (severe). Blood samples were taken at scheduled times for pharmacokinetic analysis. Postmortem examinations performed on groups 1-4 were macroscopic and microscopic evaluations, including irritation scoring and histopathology. IVRs were retained over 28 days in all but 1 animal (group 4). In all animal groups, clinical observations showed no significant abnormal findings. Pharmacokinetic analysis in the animals showed sustained release of E2 and P over a 28-day period. Irritation scores and microscopic assessments were consistent with foreign object placement. A novel 2-drug IVR delivery system was well tolerated in a sheep model and pharmacokinetic release was as expected over a 28-day release period. These results will guide future human clinical studies.
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Estradiol/farmacocinética , Estrogênios/farmacocinética , Progesterona/farmacocinética , Progestinas/farmacocinética , Administração Intravaginal , Animais , Sistemas de Liberação de Medicamentos/efeitos adversos , Sistemas de Liberação de Medicamentos/métodos , Estradiol/administração & dosagem , Estrogênios/administração & dosagem , Etilenos/química , Feminino , Progesterona/administração & dosagem , Progestinas/administração & dosagem , Ovinos , Compostos de Vinila/químicaAssuntos
Sistemas de Liberação de Medicamentos , Saúde Reprodutiva , Saúde da Mulher , Administração Intravaginal , Antineoplásicos/administração & dosagem , Antivirais/administração & dosagem , Anticoncepcionais Femininos/administração & dosagem , Endometriose/tratamento farmacológico , Feminino , Infecções por HIV/prevenção & controle , Humanos , Leiomioma/tratamento farmacológico , Neoplasias do Colo do Útero/tratamento farmacológicoRESUMO
Endometriosis and uterine fibroids (also known as uterine leiomyomas) are serious medical conditions affecting large numbers of women worldwide. Many women are asymptomatic but those with symptoms require medical intervention to relieve chronic pain and dysmenorrhea and to address infertility. Drug delivery has played a role in reducing some of the symptoms associated with endometriosis and uterine fibroids. Use of drug delivery systems for both conditions can roughly be divided into two categories: (1) existing systems designed for other indications such as contraception for symptomatic relief and (2) development of novel systems aimed at addressing some of the underlying biochemical changes associated with endometriosis and uterine fibroids such as oxidative stress, angiogenesis, and matrix degradation. The latter drug delivery approaches rely heavily on nanotechnology. Existing systems that deliver estrogens and/or progestins include vaginal rings, transdermal patches, and intrauterine systems. Long-acting implantable contraceptives such as Implanon® and injectables such as Depo-Provera® have found use in treating endometriosis. Similarly, long-acting GnRH products (e.g., Lupron Depot®) are used to treat endometriosis. Other drugs formulated in long-acting formulations include intravaginal rings capable of delivering selective progesterone receptor modulators, androgens such as danazol, and aromatase inhibitors (e.g., anastrozole). Nanoparticles composed of silica, poly(lactic-co-glycolic acid), cerium oxide, dendrimers, and chitosan/polyethyleneamine have all been investigated to improve treatment of endometriosis and to a lesser extent, uterine fibroids.
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Sistemas de Liberação de Medicamentos/métodos , Endometriose/tratamento farmacológico , Leiomioma/tratamento farmacológico , Inibidores da Aromatase/administração & dosagem , Inibidores da Aromatase/uso terapêutico , Reposicionamento de Medicamentos , Antagonistas de Estrogênios/administração & dosagem , Antagonistas de Estrogênios/uso terapêutico , Feminino , Humanos , NanotecnologiaRESUMO
The development of pericoital (on demand) vaginal HIV prevention technologies remains a global health priority. Clinical trials to date have been challenged by nonadherence, leading to an inability to demonstrate product efficacy. The work here provides new methodology and results to begin to address this limitation. We created validated scales that allow users to characterize sensory perceptions and experiences when using vaginal gel formulations. In this study, we sought to understand the user sensory perceptions and experiences (USPEs) that characterize the preferred product experience for each participant. Two hundred four women evaluated four semisolid vaginal formulations using the USPE scales at four randomly ordered formulation evaluation visits. Women were asked to select their preferred formulation experience for HIV prevention among the four formulations evaluated. The scale scores on the Sex-associated USPE scales (e.g., Initial Penetration and Leakage) for each participant's selected formulation were used in a latent class model analysis. Four classes of preferred formulation experiences were identified. Sociodemographic and sexual history variables did not predict class membership; however, four specific scales were significantly related to class: Initial Penetration, Perceived Wetness, Messiness, and Leakage. The range of preferred user experiences represented by the scale scores creates a potential target range for product development, such that products that elicit scale scores that fall within the preferred range may be more acceptable, or tolerable, to the population under study. It is recommended that similar analyses should be conducted with other semisolid vaginal formulations, and in other cultures, to determine product property and development targets.
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Quimioprevenção/métodos , Infecções por HIV/prevenção & controle , Aceitação pelo Paciente de Cuidados de Saúde , Profilaxia Pré-Exposição/métodos , Cremes, Espumas e Géis Vaginais/administração & dosagem , Adolescente , Adulto , Descoberta de Drogas/métodos , Feminino , Humanos , Pessoa de Meia-Idade , Voluntários , Adulto JovemRESUMO
INTRODUCTION: Multipurpose Prevention Technologies (MPTs) are designed to address two or more indications from a single product. The overall goal is to prevent unintended pregnancy and transmission of one or more STIs including HIV-1. AREAS COVERED: The topics covered herein are advances in over the past three years. Advances include development of novel intravaginal rings capable of releasing microbicides to prevent transmission of HIV-1 and unintended pregnancy. These rings include the potential to prevent transmission of more than one STI and unintended pregnancy. There are also gels that can potentially accomplish the same thing. Finally, combination of a drug and barrier device are also covered. EXPERT OPINION: There has been considerable advance in this field over the past three years. There is one ring currently in a Phase I clinical trial and others are soon to follow. Some of these drug delivery systems are by necessity rather complicated and hence could be prohibitively expensive in the developing world. Conducting multiple clinical trials to support regulatory approval of two or more indications represents a significant barrier. It remains unclear that women will be more motivated to use MPT products than has been observed in recent microbicide-only clinical trials. Despite these challenges, the need for MPTs remain acute hopefully ensuring they will continue to be developed over the coming years.
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Infecções por HIV/prevenção & controle , Gravidez não Planejada , Anti-Infecciosos/administração & dosagem , Dispositivos Anticoncepcionais Femininos , Sistemas de Liberação de Medicamentos/instrumentação , Sistemas de Liberação de Medicamentos/métodos , Feminino , Géis/administração & dosagem , Humanos , GravidezRESUMO
The field of controlled release has contributed significantly to female reproductive health and in particular the prevention of unintended pregnancy. For at least 50years, there have been significant advances in controlled release dosage forms used for contraception. These advances have been driven by the need to provide women a wide array of products that address adherence problems noted with oral contraceptives. The first long-acting injectable product (Depo-Provera®) was approved in the US in 1959. Since then, there has been an emphasis on development of long-acting reversible contraceptives. These products include implants, intrauterine systems, and vaginal rings. A shorter acting contraceptive option is the transdermal patch. Despite these advances there are still a large number of unplanned pregnancies around the world. New controlled release technologies will be needed to continue providing women safe and easy to use contraceptive products.
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Anticoncepção/métodos , Anticoncepcionais Femininos/química , Descoberta de Drogas/métodos , Implantes de Medicamento/química , Administração Intravaginal , Anticoncepção/instrumentação , Anticoncepção/tendências , Anticoncepcionais Femininos/administração & dosagem , Anticoncepcionais Femininos/metabolismo , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/química , Preparações de Ação Retardada/metabolismo , Descoberta de Drogas/tendências , Implantes de Medicamento/administração & dosagem , Implantes de Medicamento/metabolismo , Feminino , Humanos , Dispositivos Intrauterinos/tendências , Gravidez , Reprodução/efeitos dos fármacos , Reprodução/fisiologia , Fatores de TempoRESUMO
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.
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Anti-Infecciosos/farmacocinética , Infecções por HIV/prevenção & controle , Vagina/química , Cremes, Espumas e Géis Vaginais/farmacocinética , Administração Intravaginal , Adulto , Anti-Infecciosos/administração & dosagem , Estudos Cross-Over , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Projetos Piloto , Cintilografia , Fatores de Tempo , Tomografia Computadorizada por Raios X , Cremes, Espumas e Géis Vaginais/administração & dosagemRESUMO
This study describes the preclinical development of a matrix-type silicone elastomer vaginal ring device designed to provide controlled release of UC781, a non-nucleoside reverse transcriptase inhibitor. Testing of both human- and macaque-sized rings in a sink condition in vitro release model demonstrated continuous UC781 release in quantities considered sufficient to maintain vaginal fluid concentrations at levels 82-860-fold higher than the in vitro IC50 (2.0 to 10.4 nM) and therefore potentially protect against mucosal transmission of HIV. The 100-mg UC781 rings were well tolerated in pig-tailed macaques, did not induce local inflammation as determined by cytokine analysis and maintained median concentrations in vaginal fluids of UC781 in the range of 0.27 to 5.18 mM during the course of the 28-day study. Analysis of residual UC781 content in rings after completion of both the in vitro release and macaque pharmacokinetic studies revealed that 57 and 5 mg of UC781 was released, respectively. The pharmacokinetic analysis of a 100-mg UC781 vaginal ring in pig-tailed macaques showed poor in vivo-in vitro correlation, attributed to the very poor solubility of UC781 in vaginal fluid and resulting in a dissolution-controlled drug release mechanism rather than the expected diffusion-controlled mechanism.
Assuntos
Anilidas , Dispositivos Anticoncepcionais Femininos , Furanos , Inibidores da Transcriptase Reversa , Anilidas/administração & dosagem , Anilidas/química , Anilidas/farmacocinética , Anilidas/farmacologia , Animais , Citocinas/metabolismo , Liberação Controlada de Fármacos , Feminino , Furanos/administração & dosagem , Furanos/química , Furanos/farmacocinética , Furanos/farmacologia , Macaca , Inibidores da Transcriptase Reversa/administração & dosagem , Inibidores da Transcriptase Reversa/química , Inibidores da Transcriptase Reversa/farmacocinética , Inibidores da Transcriptase Reversa/farmacologia , Solubilidade , Tioamidas , Vagina/efeitos dos fármacos , Vagina/metabolismoRESUMO
Tenofovir gel is being evaluated for vaginal and rectal pre-exposure prophylaxis against HIV transmission. Because this is a new prevention strategy, we broadly assessed its effects on the mucosa. In MTN-007, a phase-1, randomized, double-blinded rectal microbicide trial, we used systems genomics/proteomics to determine the effect of tenofovir 1% gel, nonoxynol-9 2% gel, placebo gel or no treatment on rectal biopsies (15 subjects/arm). We also treated primary vaginal epithelial cells from four healthy women with tenofovir in vitro. After seven days of administration, tenofovir 1% gel had broad-ranging effects on the rectal mucosa, which were more pronounced than, but different from, those of the detergent nonoxynol-9. Tenofovir suppressed anti-inflammatory mediators, increased T cell densities, caused mitochondrial dysfunction, altered regulatory pathways of cell differentiation and survival, and stimulated epithelial cell proliferation. The breadth of mucosal changes induced by tenofovir indicates that its safety over longer-term topical use should be carefully monitored.
Assuntos
Mucosa/efeitos dos fármacos , Inibidores da Transcriptase Reversa/administração & dosagem , Tenofovir/administração & dosagem , Método Duplo-Cego , Feminino , Géis , Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Mitocôndrias/efeitos dos fármacos , Mucosa/metabolismo , Proteômica , Reto/efeitos dos fármacos , Reto/metabolismo , Inibidores da Transcriptase Reversa/efeitos adversos , Tenofovir/efeitos adversos , Vagina/efeitos dos fármacos , Vagina/metabolismoRESUMO
Vaginal tablets are being developed as an alternative to gels as an inexpensive, discreet dosage form for the administration of microbicides. This work describes the pharmacokinetic (PK) evaluation of rapidly disintegrating vaginal tablets containing tenofovir (TFV, 10 mg), emtricitabine (FTC, 10 mg), and the combination of TFV and FTC (10 mg each) under in vitro and in vivo conditions, and in direct comparison to the clinical TFV 1% gel, a microbicide product in Phase III clinical testing. The PK of TFV and FTC from tablets were also evaluated in female rabbits following intravaginal administration. Direct comparison of a single dose of TFV tablets (intact or predissolved at 10 mg/mL) and TFV 1% gel showed no differences in the vaginal PK of TFV between groups; however systemic bioavailability of TFV was significantly higher from the gel. When rabbits were dosed either once or daily for seven days with intact tablets of TFV, FTC, or the combination of TFV/FTC, vaginal and systemic concentrations of TFV and FTC were unaffected by co-formulation. Moreover, plasma PK parameters were similar following a single dose or seven once-daily doses. Tissue concentrations of TFV and FTC in the cranial vagina 4 h after administration ranged between 104 and 105 ng/g. Concentrations of TFV-diphospate (TFV-DP, the active metabolite) were also high (over 103 ng/g or about 3000 to 6000 fmol/mg) in the cranial vagina 4 h after administration and similar to those measured following administration of TFV 1% gel. These data demonstrate that rapidly disintegrating vaginal tablets may be a suitable topical microbicide dosage form providing similar vaginal TFV PK to that of TFV 1% gel. The data also support co-administration of FTC with TFV in a single vaginal tablet to create a combination microbicide in a simple and inexpensive dosage form.
RESUMO
INTRODUCTION: Product adherence and its measurement have emerged as a critical challenge in the evaluation of new HIV prevention technologies. Long-acting ARV-based vaginal rings may simplify use instructions and require less user behaviour, thereby facilitating adherence. One ARV-based ring is in efficacy trials and others, including multipurpose rings, are in the pipeline. Participant motivations, counselling support and measurement challenges during ring trials must still be addressed. In previous HIV prevention trials, this has been done largely using descriptive and post-hoc methods that are highly variable and minimally evaluated. We outline an interdisciplinary framework for systematically investigating promising strategies to support product uptake and adherence, and to measure adherence in the context of randomized, blinded clinical trials. DISCUSSION: The interdisciplinary framework highlights the dual use of adherence measurement (i.e. to provide feedback during trial implementation and to inform interpretation of trial findings) and underscores the complex pathways that connect measurement, adherence support and enacted adherence behaviour. Three inter-related approaches are highlighted: 1) adherence support - sequential efforts to define motivators of study product adherence and to develop, test, refine and evaluate adherence support messages; 2) self-reported psychometric measures - creation of valid and generalizable measures based in easily administered scales that capture vaginal ring use with improved predictive ability at screening, baseline and follow-up that better engage participants in reporting adherence; and 3) more objective measurement of adherence - real-time adherence monitoring and cumulative measurement to correlate adherence with overall product effectiveness through innovative designs, models and prototypes using electronic and biometric technologies to detect ring insertion and/or removal or expulsion. Coordinating research along these three pathways will result in a comprehensive approach to product adherence within clinical trials. CONCLUSIONS: Better measurement of adherence will not, by itself, ensure that future effectiveness trials will be able to address the most basic question: if the product is used per instructions, will it prevent HIV transmission? The challenges to adherence measurement must be addressed as one component of a more integrated system that has as its central focus adherence as a behaviour emerging from the social context of the user.