Effects of Flibanserin on the Pharmacokinetics of a Combined Ethinylestradiol/Levonorgestrel Oral Contraceptive in Healthy Premenopausal Women: A Randomized Crossover Study

Comparative analysis of physicochemical properties, bioequivalence, safety and tolerability of the first domestic semaglutide

Semaglutide is a representative of analogues of the incretin hormone human glucagon-like peptide-1 (GLP-1) and is currently used in Russia for the treatment of type 2 diabetes mellitus (T2DM; in monotherapy and in combination therapy), including patients with obesity and overweight.

The aim of the work was to conduct a comparative assessment of the physicochemical properties, a biological activity, bioequivalence and safety, including tolerability and immunogenicity, of the drug Quincent® (semaglutide, 1.34 mg/ml, a solution for a subcutaneous administration, Promomed Rus LLC, Russia) and the drug Ozempic® (semaglutide, 1.34 mg/ml, a solution for a subcutaneous administration, Novo Nordisk A/S, Denmark) when administered to healthy volunteers.

Materials and methods. To assess the degree of similarity of the study drug Quincenta® (semaglutide, 1.34 mg/ml, a solution for a subcutaneous administration, Promomed Rus LLC, Russia) with a chemically synthesized active substance to the original (reference) drug Ozempic® (semaglutide, 1.34 mg/ml, a solution for a subcutaneous administration, Novo Nordisk A/S, Denmark), a comparative study of physicochemical properties and a biological activity was carried out. To assess the bioequivalence of the study drug and the reference drug, an open randomized parallel comparative study with the participation of healthy volunteers (n=54), 54 participants of which had been included in the population, was conducted. The volunteers were randomized into 2 groups in a 1:1 ratio, and received a single dose subcutaneously either of the study drug (domestic semaglutide at a dose of 0.5 mg) or the reference drug (foreign semaglutide at a dose of 0.5 mg). The mode of administration was in the morning on an empty stomach. A semaglutide concentration was determined in serum samples using a previously validated enzyme-linked immunosorbent assay (ELISA) method. A quantitative determination of antibodies to semaglutide in the human serum by ELISA was carried out with a microplate photometer using ready-made kits pre-validated by the manufacturer. The conclusion about the bioequivalence of the compared drugs was made using an approach based on the assessment of 90% confidence intervals for the ratios of the geometric mean values of the parameters Cmax, AUC(0–t) of semaglutide in the measurement original units.

Results. The results of the comparative analysis of the study drug and the reference drug demonstrate the comparability of their physicochemical properties and biological activity. The results of the clinical study demonstrated the bioequivalence of the test drug and the reference drug. Thus, the pharmacokinetic parameters of the drugs were comparable to each other: the Cmax value for the study drug was 42.088±8.827 ng/ml, for the reference drug Ozempic® it was 42.2556±7.84. Herewith, the half-life for the study drug and the reference drug was 168.39±39.47 and 157.99±28.57 hours, respectively. The resulting 90% confidence intervals for the ratio of the Cmax and AUC0–t values of the study drug and the reference drug were 90.89–109.15 and 91.66–111.27%, respectively. The tolerability of the drugs in the volunteers was notified as good. No adverse events were recorded during the study. No serious adverse events were reported throughout the study. According to the results of the immunogenicity analysis, no antibodies to Russian-made semaglutide were detected in the blood serum of the volunteers, which indicated the lack of Results. The results of a comparative analysis of the study drug and the reference drug demonstrate the comparability of physicochemical properties and biological activity. The results of the clinical study demonstrated the bioequivalence of the study drug and the reference drug. Thus, the pharmacokinetic parameters of the drugs were comparable to each other: the Cmax value for the study drug was 42.088±8.827 ng/ml, for the reference drug Ozempic® this figure was 42.2556±7.84. At the same time, the half-life for the study drug and the reference drug was 168.39±39.47 and 157.99±28.57 hours, respectively. The resulting 90% confidence intervals for the ratio of the Cmax and AUC0–t values of the study drug and the reference drug were 90.89–109.15 and 91.66–111.27%, respectively. Tolerability of the drugs in volunteers was noted as good. No adverse events were recorded during the study. No serious adverse events were reported throughout the study. According to the results of the immunogenicity analysis, no antibodies to Russian-made semaglutide were detected in the blood serum of the volunteers, which indicated the lack of the drug immunogenicity.

Conclusion. In the course of the study, the comparability of the physicochemical properties and biological activity of the studied Russian drug with the chemically synthesized active substance Quincenta® to the reference drug Ozempic® was confirmed: the activity range of the studied drugs was within 80–120% in relation to the standard sample of semaglutide. The bioequivalence and a similar safety profile, including the immunogenicity and tolerability of the Russian drug Quincenta® (semaglutide 1.34 mg/ml, Promomed Rus LLC, Russia) were shown in comparison with the foreign drug Ozempic® (semaglutide 1.34 mg/ml, Novo Nordisk A/C, Denmark).

Bremelanotide for Treatment of Female Hypoactive Sexual Desire

Hypoactive sexual desire disorder (HSDD) is a persistent deficiency or absence of sexual fantasies and desire resulting in significant distress or interpersonal difficulty. Women with this disorder may display a lack of motivation for sexual activity, reduced responsiveness to erotic cues, a loss of interest during sexual activity, and avoidance of situations that could lead to sexual activity. The pathophysiology of HSDD is thought to be centered around inhibitory and excitatory hormones, neurotransmitters, and specific brain anatomy. Due to the multifactorial nature of HSDD, treatment can be complex and must attempt to target the biological and psychosocial aspects of the disorder. Bremelanotide is a melanocortin receptor agonist and has been recently approved by the FDA to treat HSDD. Bremelanotide is administered intranasally or as a subcutaneous injection. The recommended dosage of bremelanotide is 1.75 mg injected subcutaneously in the abdomen or thigh at least 45 min before sexual activity. Studies showed improvements in desire, arousal, and orgasm scores when 1.75 mg of bremelanotide was administered before sexual activity compared to a placebo. Bremelanotide is a promising way to treat HSDD.

Development and Greenness Evaluation of Spectrofluorometric Methods for Flibanserin Determination in Dosage Form and Human Urine Samples

Green, economic and sensitive two spectrofluorometric methods were developed for the quantitation of flibanserin (FB) in different matrices, which are based on FB native fluorescence properties. The first technique depends on measuring the relative fluorescence intensity of FB directly at emission and excitation wavelengths(λ_em/λ_ex) (371 nm/247 nm), while the second technique is a first derivative (D¹) spectrofluorometric method, which depends on measuring the peak amplitudes at 351 nm. Linear regressions were observed in the range of 0.1–1.5 μg/mL for both methods. Moreover, both methods were efficiently extended to analyze FB in human urine, indicating the ultra-sensitivity of the methods, and linear regression was found within a range 0.05–0.7 μg/mL for both methods. Excellent selectivity of the proposed methods and good recoveries were obtained upon the analysis of FB in pharmaceutical dosage form and human urine samples without interference from matrix components with acceptable ranges, from 98.86 to 101.46% and from 98.08 to 102.37%, respectively. Greenness of the developed methods was assessed using the national environmental method index (NEMI) and Analytical Eco-scale and Green Analytical Procedure Index (GAPI). The three approaches confirmed that the developed methods are green, safe and environment-friendly.

Improvement of sexual functioning during treatment of MDD with adjunctive pimavanserin: A secondary analysis

BACKGROUND

Sexual dysfunction is common among patients with major depressive disorder (MDD). In the CLARITY study, the safety and efficacy of adjunctive pimavanserin, an inverse agonist at 5-HT_2A receptors, were demonstrated when added to existing treatment for MDD. This analysis provides a detailed assessment of the effects of pimavanserin on sexual function from the CLARITY study.

METHODS

Patients with a diagnosis of MDD in a depressive episode, inadequate response to ongoing antidepressant therapy, and a Montgomery-Åsberg Depression Rating Scale total score >20 were randomized to pimavanserin 34 mg/day or placebo added to ongoing treatment with an immediate revision of all selective serotonin or serotonin-norepinephrine for 5 weeks (Stage 1), and nonresponders (<50% improvement from baseline in Hamilton Depression Rating Scale [HAMD-17]) were re-randomized for an additional 5 week (Stage 2). Effects of pimavanserin on the Massachusetts General Hospital Sexual Functioning Index (MGH-SFI) and HAMD-17 Item 14 (sexual interest) were examined.

RESULTS

Among 203 patients (51 on pimavanserin; 152 on placebo), pimavanserin demonstrated significant improvement from baseline to Week 5 on the MGH-SFI (least square [LS]mean difference -0.634, 95% confidence interval [CI] [-0.964, -0.304]; p = .0002; effect size [ES], Cohen's d: .614). Across Stages 1 and 2, the weighted LSmean difference was -0.468 (95% CI [-0.720, -0.216]; p = .0003) for pimavanserin versus placebo. Mean changes from baseline to Week 5 for MGH-SFI Items 1, 2, 3, and 5 and HAMD Item 14 were significantly (p < .05) greater with pimavanserin versus placebo.

CONCLUSIONS

Adjunctive pimavanserin improved sexual function in patients with MDD. Adding pimavanserin to ongoing treatment for MDD may be especially useful for patients experiencing sexual dysfunction.

Determination of flibanserin in the presence of confirmed degradation products by a third derivative emission spectrofluorometric method: Application to pharmaceutical formulation

Flibanserin is a new drug used for the treatment of hypoactive sexual desire disorder. This work is considered the first study concerning the fluorimetric behaviour of flibanserin and its new florescent degradation products. A fast, cost-effective, stability-indicating spectrofluorometric method was developed and validated for the determination of flibanserin in the presence of oxidative degradation products. Stability studies are performed to predict the behaviour of substances under various harsh conditions. Thus, flibanserin was subjected to degradation using hydrogen peroxide. The stability-indicating method was developed and validated per ICH guidelines; it was linear in the range of 0.1-3 μg/mL. The method was accurate and precise as it showed good recoveries between 98.50 and 100.90% and relative standard deviation less than 2%, respectively, and no significant differences were found after statistical comparison with the in-house HPLC method. In addition, the structures of the oxidative degradation products were confirmed using infrared spectroscopy and mass spectrometry, and the proposed degradation pathway was predicted.

Evaluation of safety for flibanserin

Introduction: Hypoactive sexual desire disorder (HSDD) is the most prevalent sexual dysfunction in women, previously managed with off-label therapies. Indicated for premenopausal women, flibanserin is the first FDA-approved medication to treat HSDD.Areas covered: This review summarizes flibanserin's pharmacokinetics, proposed mechanism of action, and safety data in clinical trials with a focus on sedation- and hypotension-related adverse events, and drug interactions with alcohol and antidepressants. Sources included peer-reviewed publications and internal data from the manufacturer.Expert opinion: Flibanserin is a well-tolerated and effective treatment that decreases distress and restores sexual desire to a level that is normative for the individual patient with HSDD. Simplification of a risk mitigation program for flibanserin in the US is likely to increase the number of prescribing clinicians if accompanied with educational efforts to clarify flibanserin's risk-benefit profile. As flibanserin is dosed daily and may be used for a decade or more in the typical premenopausal patient, long-term pharmacovigilance data will be essential. Over time, HSDD will be treated by more nonspecialist health care professionals and flibanserin will likely become established as a significant treatment option along with other medications approved for this indication in the context of a holistic biopsychosocial treatment paradigm.

Quantitative determination of levonorgestrel in beagle dog plasma after vaginal administration of intravaginal ring by high-performance liquid chromatography-tandem mass spectrometry

A specific and sensitive high-performance liquid chromatography-tandem mass spectrometry method that could be used to determine the concentration of levonorgestrel (LNG) in beagle dog plasma was developed. Specifically, terfenadine was used as the internal standard (IS). The separation was achieved on a Kinetex-C₁₈ 110A column (3 × 30 mm i.d., 2.6 um, Phenomenex) and a gradient mobile phase consists of methanol (0.1% formic acid) and water (0.1% formic acid) was used. The flow rate was 0.8 mL/min and the injection volume was 10 μL. The detection was performed on a triple-quadruple tandem mass spectrometer by multiple reaction monitoring mode via electrospray ionization. Quantitative analysis was carried out at m/z 313.0 → 108.9 and m/z 472.6 → 436.2 for LNG and IS respectively. This method demonstrated the linearity of LNG over a concentration range of 0.5-50 ng/mL with a coefficient correlation (r) of 0.9973. The lower limit of quantification was 0.5 ng/mL. The intra- and inter-assay precisions were 2.9 and 11.2%, with an accuracy range from 94.8 to 108.4%. The stability data indicated that sample preparation and storage process had little effect on the concentration of LNG QC sample. The validated method was successfully applied to study the pharmacokinetics of LNG in beagle dog after vaginal administration of intravaginal ring.