Flibanserin for the treatment of hypoactive sexual desire disorder in premenopausal women

A Different Perspective on the Characterization of a New Degradation Product of Flibanserin With HPLC-DAD-ESI-IT-TOF-MSn and Its Pharmaceutical Formulation Analysis With Inter-Laboratory Comparison

BACKGROUND

Flibanserin (FLB) was first synthesized as an antidepressant drug; however, due to its enhancing effects on sexual activity, it was approved for treatment of hypoactive sexual desire disorder in women in 2015.

OBJECTIVE

The aim of this study was to develop a new and fully validated HPLC method for analysis of FLB in pharmaceutical formulations besides its degradation products, and identification of possible formation mechanisms by using HPLC-DAD-ESI-IT-TOF-MSn.

METHOD

The HPLC separation was achieved in a Supelco Ascentis® Express series phenyl hexyl column (100 × 4.6 mm, ID 2.7 µm). The mobile phase was acetonitrile-ammonium acetate solution (50:50, v/v, 10 mM, pH 5.4) mixture, which was pumped at the rate of 0.5 mL/min. Chromatography, detection, and structural identification was performed by using a LCMS-IT-TOF instrument (Shimadzu, Japan).

RESULTS

1-(2-(4-(3-hydroxy-5-(trifluoromethyl)phenyl)piperazine-1-yl)ethyl)-1,3-dihydro-2H-benzo[d]imidazol-2-one is proposed as a novel degradation product, with a mass of 407.1695 and a formula of C20H21F3N4O2 with a margin of error about 0.001 ppm. The developed method is applicable with 98% accuracy within the 2.5-50.0 µg/mL range. The LOD and LOQ were about 500 ng/mL and 1.50 µg/mL, respectively. The transferability and variation between laboratories were tested by inter-laboratory comparison and evaluated with one-way analysis of variance.

CONCLUSIONS

A novel FLB degradation product, which was produced under oxidative forced degradation conditions was observed and identified for the first time; in addition, the formation kinetics of the degradation product besides decomposition of FLB was studied. Furthermore, an inter-laboratory comparison was carried out, and application of the proposed method on a pseudo Addyi® (Sprout Pharmaceuticals, Inc.) sample was tested using both instrument configurations.

HIGHLIGHTS

A novel stability-indicating assay method was developed and fully validated according to the International Council on Harmonization (Q2) R1 for the analysis of FLB in the pharmaceutical preparations. A new degradation product was identified in the oxidative forced degradation condition and characterized using HPLC-DAD-ESI-IT-TOF-MS3. Moreover, the possible mechanism and the formation kinetic of the degradation product were revealed. In addition, the developed method was transferred to another LC-PDA instrument for inter-laboratory comparison. Finally, the current method was applied to a pseudo formulation of Addy in both instruments, and ANOVA was applied for evaluation.

Pharmacotherapy for female sexual dysfunctions (FSDs): what is on the market and where is this field heading?

INTRODUCTION

Female sexual dysfunctions (FSDs) are common in women of any age and have a huge impact on quality of life and relationships. They have a multifaceted etiology limiting the development of pharmacotherapies with a high rate of effectiveness. Safety issues are also a concern.

AREAS COVERED

The authors report the most recent advances in pharmacotherapy for premenopausal and postmenopausal women with a main focus on hypoactive sexual desire disorders (HSDD) and associated sexual symptoms. Good levels of evidence have emerged for psychoactive agents, such as flibanserin and bremelanotide, as well as hormonal compounds (transdermal testosterone). The authors also report briefly on intravaginal DHEA (prasterone), local estrogen therapy (LET), and ospemifene to manage effectively vulvovaginal atrophy/genitourinary syndrome of menopause (VVA/GSM). In addition, they discuss promising therapeutic options highlighting the main reasons that hamper the availability of new labeled products. Finally, they include the importance of the multimodal approach to address FSDs.

EXPERT OPINION

Approved pharmacotherapies for FSD are limited. Validated multidimensional instruments and adequate objective measures of physical and mental responses to sexual external and internal incentives are mandatory to identify women suitable to chronic or on-demand treatments and to assess their pattern of response in research and practice.

Female sexual dysfunctions: an overview on the available therapeutic interventions

INTRODUCTION

There are different types of female sexual dysfunctions (FSDs), and FSD in general has a high prevalence worldwide. Studies of FSD should consider it as a multifactorial disorder that has biological, psychological, environmental, and relational aspects. In this review we discuss the available therapeutic interventions for FSD.

EVIDENCE ACQUISITION

For the current narrative review the PubMed database was searched to identify all publications up to 30 March 2021 that were systematic reviews and meta-analyses which examined therapeutic interventions for FSDs based on the diagnostic classifications of ICD-10 and ICD-11.

EVIDENCE SYNTHESIS

Thirty systematic reviews and meta-analyses were included in this review. Hormone therapy (HT) and testosterone are effective to improve sexual desire in menopausal women. In these women HT and ospemiphene may improve pain during intercourse. Flibanserin may improve sexual desire and may reduce desire-related distress in premenopausal women. Bremelanotide is effective to improve desire, arousal, and orgasm scores. Evidence are still limited on the efficacy of psychoactive drugs, phosphodiesterase type 5 (PDE5), oxytocin, herbal drugs, and tibolone to treat FSDs. Psychological interventions such as cognitive-behavior therapy, mindfulness training, sensate focus, bibliotherapy are effective for the management of several different FSDs.

CONCLUSIONS

The management of FSDs may require multidisciplinary and interdisciplinary approaches. Pharmacological and nonpharmacological interventions appears to have potential as a treatment for FSDs, but there are currently no gold standards regarding recommended treatment modalities, and the duration, frequency, and intensity of therapy sessions.

The Bio-Psycho-Social Dimension in Women's Sexual Desire: 'Argumentum ad novitatem'

Sexual desire includes complex motivation and drive. In the context of biological and cognitive- emotive state art of science, it is often a neglected field in medicine. In regard to the treatment, study on women's sexual function received less attention compared to the men's sexuality. In the past, this endeavor was relatively not well disseminated in the scientific community. Recently, there was a revolutionized surge of drug targets available to treat women with low sexual desire. It is timely to review the relevant biological approach, especially in the context of pharmacotherapy to understand this interesting clinical entity which was modulated by numerous interactive psychosocial inter-play and factors. The complex inter-play between numerous dimensional factors lends insights to understand the neural mechanism, i.e. the rewards centre pathway and its interaction with external psychosocialstimulus, e.g. relationship or other meaningful life events. The function of hormones, e.g. oxytocin or testosterone regulation was described. The role of neurotransmitters as reflected by the introduction of a molecule of flibenserin, a full agonist of the 5-HT1A and partial agonist of the D4 to treat premenopausal women with low sexual desire was deliberated. Based on this fundamental scientific core knowledge, we suggest an outline on know-how of introduction for sex therapy (i.e. "inner-self" and "outer-self") where the role of partner is narrated. Then, we also highlighted on the use of pharmacological agent as an adjunct scope of therapy, i.e. phosphodiasterase-5 (PDE-5) inhibitors and hormonal treatment in helping the patient with low sexual desire.

Optimisation by Design of Experiment of Benzimidazol-2-One Synthesis under Flow Conditions

A novel flow-based approach for the preparation of benzimidazol-2-one (1) scaffold by the 1,1′-carbonyldiimidazole (CDI)-promoted cyclocarbonylation of o-phenylenediamine (2) is reported. Starting from a preliminary batch screening, the model reaction was successfully translated under flow conditions and optimised by means of design of experiment (DoE). The method allowed the efficient preparation of this privileged scaffold and to set up a general protocol for the multigram-scale preparation in high yield, purity, and productivity, and was successfully applied for the multigram flow synthesis of N-(2-chlorobenzyl)-5-cyano-benzimidazol-2-one, which is a key synthon for hit-to-lead explorations in our anti-inflammatory drug discovery program.

Understanding the Role of Serotonin in Female Hypoactive Sexual Desire Disorder and Treatment Options

BACKGROUND

The neurobiology of sexual response is driven in part by dopamine and serotonin-the former modulating excitatory pathways and the latter regulating inhibitory pathways. Neurobiological underpinnings of hypoactive sexual desire disorder (HSDD) are seemingly related to overactive serotonin activity that results in underactive dopamine activity. As such, pharmacologic agents that decrease serotonin, increase dopamine, or some combination thereof, have therapeutic potential for HSDD.

AIM

To review the role of serotonin in female sexual function and the effects of pharmacologic interventions that target the serotonin system in the treatment of HSDD.

METHODS

Searches of the Medline database for articles on serotonin and female sexual function.

OUTCOMES

Relevant articles from the peer-reviewed literature were included.

RESULTS

Female sexual response is regulated not only by the sex hormones but also by several neurotransmitters. It is postulated that dopamine, norepinephrine, oxytocin, and melanocortins serve as key neuromodulators for the excitatory pathways, whereas serotonin, opioids, and endocannabinoids serve as key neuromodulators for the inhibitory pathways. Serotonin appears to be a key inhibitory modulator of sexual desire, because it decreases the ability of excitatory systems to be activated by sexual cues. Centrally acting drugs that modulate the excitatory and inhibitory pathways involved in sexual desire (eg, bremelanotide, bupropion, buspirone, flibanserin) have been investigated as treatment options for HSDD. However, only flibanserin, a multifunctional serotonin agonist and antagonist (5-hydroxytryptamine [5-HT]_1A receptor agonist and 5-HT_2A receptor antagonist), is currently approved for the treatment of HSDD.

CLINICAL IMPLICATIONS

The central serotonin system is 1 biochemical target for medications intended to treat HSDD.

STRENGTHS AND LIMITATIONS

This narrative review integrates findings from preclinical studies and clinical trials to elucidate neurobiological underpinnings of HSDD but is limited to 1 neurotransmitter system (serotonin).

CONCLUSION

Serotonin overactivity is a putative cause of sexual dysfunction in patients with HSDD. The unique pharmacologic profile of flibanserin tones down inhibitory serotonergic function and restores dopaminergic and noradrenergic function. Croft HA. Understanding the Role of Serotonin in Female Hypoactive Sexual Desire Disorder and Treatment Options. J Sex Med 2017;14:1575-1584.

Flibanserin: A controversial drug for female hypoactive sexual desire disorder

Sexual functioning is an integral part of human life. Female sexual dysfunction (FSD) adversely affects quality of life and general well-being. The Food and Drug Administration recently approved flibanserin, for treatment of female hypoactive sexual desire disorder (HSDD), regarded as the most common FSD, amid great controversy. A novel multifunctional serotonin agonist and antagonist, flibanserin, has been shown to be efficacious in treating HSDD but with a rather tenacious side effect profile. We review this interesting drug in its entirety. Data for the article were collected by reviewing articles on PubMed, the drug (Addyi) website, and related websites on the internet.

Route to Benzimidazol-2-ones via Decarbonylative Ring Contraction of Quinoxalinediones: Application to the Synthesis of Flibanserin, A Drug for Treating Hypoactive Sexual Desire Disorder in Women and Marine Natural Product Hunanamycin Analogue

A simple and practical method to access a variety of benzimidazol-2-ones is reported here. A series of N-alkyl-substituted benzimidazol-2-ones were synthesized by decarbonylative ring contraction starting from corresponding quinoxalinediones for the first time. The utility of the method has been demonstrated by synthesizing recently approved controversial drug flibanserin (Addyi) and a urea analogue of marine antibiotic natural product hunanamycin-A.

Herbal medicine for low sexual desire in menopausal women: A clinical review

Many women typically experience a significant reduction in sexual desire during the late perimenopausal and early postmenopausal stages, with the biggest decline in sexual desire occurring from three years prior to two years after the final menstrual period. Despite being a prevalent female complaint, currently no standard treatment for low sexual desire exists. Herbal medicines have been used therapeutically all around the world, and are an important component of Traditional and Complementary Medicine. There have been numerous trials and pharmacological studies of specific herbal preparations related to the treatment of low sexual desire. This article serves to provide a clinical review of the evidence relating to the herbal treatment options for this common condition.