Bioequivalence study of a new sildenafil 100 mg orodispersible film compared to the conventional film-coated 100 mg tablet administered to healthy male volunteers

An overview of conventional and investigational phosphodiesterase 5 inhibitors for treating erectile dysfunction and other conditions

INTRODUCTION

There is a rising concern about developing innovative, efficacious PDE5I molecules that provide better safety, efficacy, and tolerability with less adverse effects. Innovative PDE5I with dual targets have also been defined in the literature. Additionally, some of PDE5I are able to selectively inhibit other enzymes such as histone deacetylase, acetylcholine esterase, and cyclooxygenase or act as nitric oxide donors. This review presents knowledge concerning the advanced trends and perspectives in using PDE5I in treatment of ED and other conditions.

AREAS COVERED

Pre-clinical and early clinical trials that investigated the safety, efficacy, and tolerability of novel PDE5I such as Udenafil, Mirodenafil, Lodenafil, Youkenafil, Celecoxib, and TPN729 in treatment of ED and other conditions.

EXPERT OPINION

Preclinical and limited early clinical studies of the new molecules of PDE5I have demonstrated encouraging results; however, safety, efficacy, and tolerability are still issues that necessitate further long-term multicenter clinical studies to ensure justification of their uses in treatment of ED and other conditions. Progress in molecular delivery techniques and tailored patient-specific management and additional therapeutic technology will dramatically improve care for ED and other conditions. The dream of ED and many other conditions becoming more effectively managed may be feasible in the near future.

Drug dissolution and transit in a heterogenous gastric chyme after fed administration: Semi-mechanistic modeling and simulations for an immediate-release and orodispersible tablets containing a poorly soluble drug

Mathematical models that treat the fed stomach content as a uniform entity emptied with a constant rate may not suffice to explain pharmacokinetic profiles recorded in clinical trials. In reality, phenomena such as the Magenstrasse or chyme areas of different pH and viscosity, play an important role in the intragastric drug dissolution and its transfer to the intestine. In this study, we investigated the data gathered in the bioequivalence trial between an immediate-release tablet (Reference) and an orally dispersible tablet (Test) with a poorly soluble weak base drug administered with or without water after a high-fat high-calorie breakfast. Maximum concentrations (Cmax) were significantly greater after administering the Reference product than the Test tablets, despite similar in vitro dissolution profiles. To explain this difference, we constructed a novel semi-mechanistic IVIVP model including a heterogeneous gastric chyme. The drug dissolution in vivo was modeled from the in vitro experiments in biorelevant media simulating gastric and intestinal fluids in the fed state (FEDGAS and FeSSIF). The key novelty of the model was separating the stomach contents into two compartments: isolated chyme (the viscous food content) that carries the drug slowly, and aq_chyme open for rapid Magenstrasse-like routes of drug transit. Drug distribution between these two compartments was both formulation- and administration-dependent, and recognized the respective drug fractions from the clinical pharmacokinetic data. The model's assumption about the nonuniform mixing of the API with the chyme, influencing differential drug dissolution and transit kinetics, led to simulating plasma concentration profiles that reflected well the variability observed in the clinical trial. The model indicated that, after administration, the Reference product mixes to a greater extent with aq_chyme, where the released drug dissolves better and transfers faster to the intestine. In conclusion, this novel approach underlines that diverse gastric emptying of different oral dosage forms may significantly impact pharmacokinetics and affect the outcomes of bioequivalence trials.

Orodispersible Films: Current Innovations and Emerging Trends

Orodispersible films (ODFs) are thin, mechanically strong, and flexible polymeric films that are designed to dissolve or disintegrate rapidly in the oral cavity for local and/or systemic drug delivery. This review examines various aspects of ODFs and their potential as a drug delivery system. Recent advancements, including the detailed exploration of formulation components, such as polymers and plasticizers, are briefed. The review highlights the versatility of preparation methods, particularly the solvent-casting production process, and novel 3D printing techniques that bring inherent flexibility. Three-dimensional printing technology not only diversifies active compounds but also enables a multilayer approach, effectively segregating incompatible drugs. The integration of nanoparticles into ODF formulations marks a significant breakthrough, thus enhancing the efficiency of oral drug delivery and broadening the scope of the drugs amenable to this route. This review also sheds light on the diverse in vitro evaluation methods utilized to characterize ODFs, ongoing clinical trials, approved marketed products, and recent patents, providing a comprehensive outlook of the evolving landscape of orodispersible drug delivery. Current patient-centric approaches involve developing ODFs with patient-friendly attributes, such as improved taste masking, ease of administration, and enhanced patient compliance, along with the personalization of ODF formulations to meet individual patient needs. Investigating novel functional excipients with the potential to enhance the permeation of high-molecular-weight polar drugs, fragile proteins, and oligonucleotides is crucial for rapid progress in the advancing domain of orodispersible drug delivery.

News and future perspectives of non-surgical treatments for erectile dysfunction

The significant discontinuation rate of available therapies and the paucity of curative options promoted the research on potential novel treatments suitable for erectile dysfunction patients. The aim of this study was to provide a summary of available evidence regarding the news and future perspectives related to the non-surgical treatment of erectile dysfunction. A narrative review of the literature was performed. A comprehensive search in the MEDLINE, Embase, and Scopus databases was done. Papers in English-language, published until April 2022, were included. No chronological restriction was applied. Retrospective and prospective clinical studies, as well as meta-analyses, were considered. Oro-dispersible formulations of phosphodiesterase type 5 inhibitors are particularly indicated in patients who have difficulty in swallowing solid dosage form; in addition, they constitute a discrete route of administration not requiring water. Low-intensity extracorporeal shock wave therapy is indicated in mild vasculogenic erectile dysfunction and in patients with vasculogenic erectile dysfunction poorly responsive to phosphodiesterase type 5 inhibitors. Stem cell therapy, platelet-rich plasma injections, and gene therapy seem promising regenerative treatments for selected patients with erectile dysfunction. Novel oral formulations of drugs commonly used in erectile dysfunction patients have recently become part of standard clinical practice. Regenerative treatments have been emerging in recent years and could become routine curative options in the near future. Further well-designed randomized controlled trials are needed to provide conclusive evidence on this topic and guide appropriate recommendations.

Overview about Oral Films in Mental Disorders

Mental disorders are increasing worldwide, and efforts have been developed by multidisciplinary research groups to combine knowledge from different areas such as psychology, neuroscience, medicine, and biotechnology to develop strategies and products to promote the prevention of mental disorders. Excessive antipsychotic consumption is a public health problem, and innovative strategies must be devised. The development of innovative and, if possible, natural products is one of the strategies to combat this public health problem. Oral films are recent delivery systems that have been developed with several advantages that should be applied in this area. This review intends to draw attention to these new dosage forms of drugs and bioactive molecules pertinent to the field of mental health prevention and therapy and to the need for regulatory guidelines to ensure their quality and safety. This is a critical overview about strengths, weaknesses, opportunities, and threats related to oral film implementation in mental disorder treatment.

Bioequivalence Studies of Sildenafil Citrate Orodispersible Film Administered with and without Water vs ViagraⓇ Film-Coated Tablets in Healthy Male Volunteers

Background

Orodispersible film (ODF) formulation offers ease of use, convenience of administration, and other advantages, especially for patients who have difficulty in swallowing or are on liquid restriction compared with conventional oral formulations for the treatment of erectile dysfunction.

Objectives

These studies compared the bioequivalence of 50 mg sildenafil citrate ODF formulation (test drug) with the marketed 50 mg sildenafil citrate film-coated tablet (FCT) (Viagra^Ⓡ; Pfizer, New York, NY) (reference drug), with and without water in 2 randomized cross-over studies.

Methods

Two randomized cross-over studies were conducted. The first study explored the bioequivalence of test drug administered with and without water compared with the reference drug with water. The second study investigated the bioequivalence of test drug, without water, compared with the reference drug with water. Forty-two and 80 healthy male volunteers were recruited in the first and second study, respectively. All volunteers fasted for 10 hours pre-dose. A 1-day washout period between doses was observed. Blood samples were collected at both before (up to 120 minutes before dosing) and after dosing (at different intervals up to 14 hours) stages. Statistical analyses on pharmacokinetic parameters were performed. Safety and tolerability for both the formulations were evaluated.

Results

In the first study, bioequivalence was demonstrated for sildenafil citrate ODF administered with water when compared with the Viagra^Ⓡ FCT. The ratios of adjusted geometric means (90% confidence interval (CI)) were maximum plasma concentration: 1.02 (94.91-108.78) and area under the plasma concentration-time curve: 1.09 (104.49-113.21) for sildenafil citrate ODF administered with water vs Viagra^Ⓡ FCT. These ratios were within the bioequivalence acceptance range of 80% to 125%, indicating that the bioequivalence criteria were met. The pharmacokinetic parameters for the second study also showed bioequivalence for sildenafil citrate ODF (without water) compared with Viagra^Ⓡ FCT. The ratios of adjusted geometric means (90% CI) were maximum plasma concentration: 1.02 (95.47-109.36) and area under the plasma concentration-time curve: 1.06 (103.42-108.40) for sildenafil citrate ODF administered without water vs Viagra^Ⓡ FCT. Adverse events in both the studies occurred at similar rates for the 2 formulations and were mild in intensity.

Conclusions

These results suggest that the new ODF formulation can be used interchangeably with the marketed FCT formulation. Sildenafil citrate ODF administered with and without water met bioequivalence criteria compared with Viagra^Ⓡ FCT administered with water under fasted conditions in healthy adult male volunteers. The new ODF formulation can be used as a suitable alternative to the conventional oral solid dosage form.

Orodispersible Film Based on Maltodextrin: A Convenient and Suitable Method for Iron Supplementation

Orodispersible film (ODF) is an innovative dosage form used to administer drugs and nutrients, designed to disintegrate or dissolve in the oral cavity without needing water. One of the advantages of ODF is that it is suitable for administration in older people and children who have difficulty swallowing because of psychological or physiological deficiencies. This article describes the development of an ODF based on maltodextrin, which is easy to administer, has a pleasant taste, and is suitable for iron supplementation. An ODF containing 30 mg of iron as pyrophosphate and 400 µg of folic acid (iron ODF) was developed and manufactured on an industrial scale. The kinetic profile for serum iron and folic acid upon consumption of ODF compared with a Sucrosomial^® iron capsule (known for its high bioavailability) was evaluated in a crossover clinical trial. The study was conducted in nine healthy women, and the serum iron profile (AUC_0-8, T_max, and C_max) of both formulations was defined. Results showed that the rate and extent of elemental iron absorption with iron ODF was comparable to that obtained using the Sucrosomial^® iron capsule. These data represent the first evidence of iron and folic acid absorption concerning the newly developed ODF. Iron ODF was proven to be a suitable product for oral iron supplementation.

Effect of the new 75-mg orodispersible film of sildenafil on erection and sexual quality of life: insights from an observational study

Background

The newly devised orodispersible film (ODF) of sildenafil is the first phosphodiesterase type 5 inhibitor (PDE5i) available in a 75-mg dose. This intermediate dose and the particular properties of the ODF formulation can improve the clinical management of erectile dysfunction (ED) patients.

Aim

We investigated the effects of the sildenafil ODF 75-mg dose on both sexual quality of life and erectile function based on the results from an observational study in daily practice in Italy.

Methods

This study was a post hoc analysis of results from an observational, real-life study carried out in ED patients at 6 treatment centers in Italy. All subjects were asked to take the prescribed dose of sildenafil ODF at inclusion (visit 1) and to return for a control visit (visit 2) to confirm or adapt the prescribed dose after a minimum of 4 weeks. An end of study control visit (visit 3) was performed after additional 4 weeks.

Outcomes

Erectile function, assessed by the International Index of Erectile Function-Erectile Function (IIEF-EF) domain; sexual quality of life, measured using the sexual quality of life instrument for men (SQoL-M).

Results

Among the 36 subjects initially recruited for the 75-mg dose, 5 patients dropped out of the study (2 at visit 2 and 3 at visit 3), none of whom due to treatment inefficacy or serious adverse events. At visit 2, the mean (SD) IIEF-EF scores significantly increased (∆ = 7.97 [4.71], P < 0.0001) as SQoL-M scores also did (∆ = 10.76 [10.46], P < 0.0001). At visit 3, IIEF-EF and SQoL-M scores were still significantly improved compared to baseline (∆ = 10.64 [7.01], P < 0.0001, and ∆ = 18.15 [12.32], P < 0.0001, respectively). By ANCOVA, we found no significant effects for age, BMI, previous use of PDE5i, presence of metabolic comorbidities, or smoking habits on study outcomes at both visits 2 and 3.

Clinical implication

The new 75-mg ODF sildenafil formulation is a safe and effective treatment for ED, significantly improving both erectile function and sexual quality of life in patients undergoing treatment.

Strengths and limitations

This is the first study assessing the efficacy of the sildenafil ODF 75-mg dose in a real-life setting. However, the small sample size, possible underlying cultural factors, and limited availability of clinically relevant data may have affected the reliability of our results.

Conclusion

The use of the 75 mg ODF formulation for sildenafil represents an effective and safe novel treatment option for ED patients.

Comparing the gastric emptying of 240 mL and 20 mL water by MRI and caffeine salivary tracer technique

Gastrointestinal fluid volumes are a crucial parameter for dissolution and absorption of orally taken medications. Most often 240 mL are used in clinical standard setups. Nonetheless, surveys in patient populations revealed dramatically lower volumes for intake of oral medications in real life and even in some clinical studies reduced fluid volumes are common. These reductions might have serious impact on pharmacokinetics. Thus, it was the aim of this study to compare the gastric emptying of 240 mL and 20 mL of water in 8 healthy volunteers. For investigation of gastric fluid volumes Magnetic Resonance Imaging with strongly T2 weighted sequences was used. Gastric emptying was additionally quantified via caffeine pharmacokinetics measured in saliva. The absolute gastric volumes after intake of 240 mL or 20 mL obviously differed by factor 10 but relative gastric emptying expressed as fraction per time was nearly comparable. Only slighter slower emptying after intake of 20 mL was observed. Salivary caffeine pharmacokinetics representing mass transfer from stomach to small intestine after intake of different volumes did not differ. The absorbed caffeine fraction and emptied gastric volume fraction correlated well after intake of 240 mL, but not after intake of 20 mL, indicating a higher influence of secretion on gastric volume measurements after intake of smaller volumes. Relative gastric emptying as measured with MRI and salivary caffeine method was only slightly delayed, thus transfer of orally administered drug fraction could be comparable even with lower fluid intake as can be seen by comparable caffeine pharmacokinetics. Nonetheless, the considerably reduced volumes might interfere with dissolution and absorption.

Orodispersible Film (ODF) Platform Based on Maltodextrin for Therapeutical Applications

Orodispersible film (ODF) is a new dosage form that disperses rapidly in the mouth without water or swallowing. The main ingredient of an ODF is a polymer that can be both of natural or synthetic origin. Maltodextrin is a natural polymer, mainly used in pharmaceutical and nutraceutical fields. This review aims to examine the literature regarding ODFs based on maltodextrin as the platform for developing new products for therapeutical application. ODFs based on maltodextrin contain plasticizers that enhance their flexibility and reduce their brittleness. Surfactants; fillers, such as homopolymer and copolymer of vinylacetate; flavour and sweetener were introduced to improve ODF characteristics. Both water-soluble and insoluble APIs were introduced up to 100 mg per dosage unit. The solvent casting method and hot-melt extrusion are the most useful techniques for preparing ODFs. In particular, the solvent casting method allows manufacturing processes to be developed from a lab scale to an industrial scale. ODFs based on maltodextrin are characterized in terms of mechanical properties, dissolution rate, taste and stability. ODFs made of maltodextrin, developed by IBSA, were tested in vivo to evaluate their bioequivalence and efficacy and were demonstrated to be a valid alternative to the marketed oral dosage forms.

An Insight into Preparatory Methods and Characterization of Orodispersible Film-A Review

Over the past few decades, researchers and companies have been trying to develop novel drug delivery systems to ensure safety, efficacy, compliance, and patient acceptability. Nowadays drug discovery and development are expensive, complex, and time-consuming processes, but trends are moving toward novel drug delivery systems. This delivery system helps to achieve drug response by local and systemic action through different routes. This novel approach of preparing orodispersible films (ODFs) provides benefits to paediatric, geriatric, and bedridden patients. This review paper aims to provide details on the preparation, characterization, and evaluation of ODFs; it also aims to focus on the positive and negative factors that affect film formulation and give an insight into potential drug candidates and polymers for use in ODFs. ODFs are effective, safe, and have good bioavailability as compared to fast-disintegrating tablets. The novel approach has various advantages because it provides instant effects in emergency situations and in schizophrenic and dysphasic patients without the need for taking water, the films disintegrating within a few seconds in the oral cavity. The solvent casting method is the most frequently used technique to develop ODFs, using film-forming polymers, which have a fast disintegration time, improved drug dissolution, and better drug contents.

Assessment of a New Formulation of Sildenafil on Common Practice: An Observational Study

Erectile dysfunction (ED) has a significant impact on the quality of life of patients. Xybilun® (IBSA Pharma SAS, France) is a new formulation of sildenafil in an orodispersible film (ODF). This study aims to assess the response rate (RR), satisfaction with, and safety of sildenafil-ODF in daily practice in France. Patients aged ≥18 years with ED were included in four groups: Group 1 mild, Group 2 moderate, Group 3 severe ED, according to the International Index for Erectile Function (IIEF)-6 subscore, never treated with phosphodiesterase inhibitors (PDE)5-I; Group 4, patients previously treated with another PDE5-I. Patients were evaluated at baseline (V1), one (V2), and three (V3) months. The RR and satisfaction were assessed using the IIEF-6 subscore questionnaire, a 5-point Likert scale, and a Global Assessment Question (GAQ). The primary endpoint for Groups 1 to 3 was the RR according to Rosen criteria at V3 compared to V1. For Group 4, the primary endpoint was the RR, defined as the satisfaction compared with previous treatment. Secondary endpoints were the RR at V2 compared to V1, the evolution of IIEF-6 and IIEF-15 scores, dose adjustment, satisfaction, convenience, and safety. One hundred and five patients were enrolled, 83 analysed. The RR at V3 was 100% (Group 1); 75% (Group 2); 65.2% (Group 3); and 84.2% (Group 4). The overall RR was 78.3%. Secondary parameters confirmed the satisfaction with sildenafil-ODF, with 81.6% of patients very satisfied at V3. No Serious Adverse Events (SAEs) were observed. In conclusion, sildenafil-ODF seems beneficial for patients irrespective of the severity of the ED. This study confirms in the context of daily clinical practice the satisfaction of patients with sildenafil-ODF. Data suggest that the availability of the intermediate dose of 75 mg could add greater flexibility to the therapy.

Comparative Bioavailability Study of a New Vitamin D3 Orodispersible Film Versus a Marketed Oral Solution in Healthy Volunteers

BACKGROUND AND OBJECTIVE

An orally disintegrating film (ODF) formulation of vitamin D3 that dissolves rapidly in the mouth without drinking or chewing may be a worthwhile alternative to currently available drug products for therapeutic vitamin D supplementation. This study aimed to compare the bioavailability of a single dose of a vitamin D3 25000 I.U. ODF with those of a marketed oral vitamin D3 preparation in healthy subjects.

METHODS

This Phase 1, randomised, parallel-group, open-label study compared the pharmacokinetics of calcifediol [25(OH)D3], the precursor of bioactive vitamin D3, after a single dose of a new vitamin D3 25,000 I.U. ODF with those of a Reference formulation (vitamin D3 25000 I.U./2.5 mL oral solution) in healthy adult subjects using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay. The primary objective was bioavailability under fed conditions, defined as maximum plasma concentration (C_max) of 25(OH)D3 and area under the concentration-time curve from time zero to time t, the last quantifiable concentration (AUC_0-t). The pharmacokinetics of 25(OH)D3 were also evaluated following the ODF administration under fasting conditions. Subjects were randomised to receive a single dose of the vitamin D3 25000 I.U. ODF or the Reference oral solution under fed conditions or the vitamin D3 ODF under fasting conditions.

RESULTS

Forty-eight healthy subjects were randomised and completed the study. Overall, the pharmacokinetic profile was very similar across the three treatment groups, and bioavailability did not significantly differ among treatments. Under fed conditions, mean 25(OH)D3 plasma values for C_max were 6.68 ± 2.03 versus 6.61 ± 2.62 ng/mL for the Test versus Reference formulations. Corresponding values for AUC_0-t were 2364.80 ± 1336.97 versus 2150.52 ± 1622.76 ng/mL × h. Mean C_max was slightly lower (6.68 ± 2.03 vs 7.23 ± 1.48 ng/mL) and the time to reach peak concentration was delayed (144 h [36-312] versus 42 h (2-480]) with the ODF under fed versus fasting conditions (p = 0.0371). The point estimates and 90 % CIs of the Test_fed/Reference_fed ratios of the geometric means showed that the bioavailability of exogenous 25(OH)D3 was, both in rate and extent of absorption, slightly higher with the vitamin D3 ODF than the vitamin D3 oral solution under the administration conditions recommended for the vitamin D3 oral solution. Palatability and ease of use of the ODF were satisfactory.

CONCLUSION

The new ODF 25000 I.U. formulation provided a valuable alternative to the marketed oral solution for therapeutic vitamin D supplementation, with a bioavailability that was slightly higher than that of the vitamin D3 oral solution administered under the same conditions.

TRIAL REGISTRATION

The study was retrospectively registered with the ISRCTN Registry (Registry code: ISRCTN13208948) on 27 November 2020.

Efficacy of the Orally Disintegrating Strip Sildenafil for the Treatment of Erectile Dysfunction: A Prospective, Randomized Trial

Introduction

Phosphodiesterase 5 inhibitors are the predominant treatment option for erectile dysfunction.

Aim

This study evaluates the efficacy and safety of sildenafil orally disintegrating strips for the treatment of erectile dysfunction.

Methods

One hundred twenty erectile dysfunction patients were enrolled in a prospective, randomized, controlled crossover study and allocated into 2 groups of 60 participants. Patients were either treated with sildenafil strips or tablets for 8 weeks after which they crossed over into the alternate treatment formulation for another 8 weeks following a 4-week wash-out period. Each participant was assessed 8 times throughout the study period and their formulation preference registered at the end of the study.

Main outcomes and measures

Changes in the abridged International Index of Erectile Function (IIEF-5) score and Erection Hardness Score (EHS) resulting from sildenafil orally disintegrating strip or tablet treatments were the primary end points, with differences in onset of action, duration of action, and incidence of adverse events between the 2 formulations included as secondary end points.

Results

Both sildenafil formulations were effective in treating patients with erectile dysfunction. There was significant improvement of erectile function in term of IIEF-5 score and EHS from both formulations. The number and type of adverse events were also comparable. Likewise, there were no statistically significant differences between the earliest onset of action times and longest duration of action times. However, the results showed a 7.1-minute earlier onset of action time for orally disintegrating strips that may be considered as clinically meaningful by some patients.

Conclusion

Sildenafil orally disintegrating strips are a safe and effective alternative to the conventional tablet formulation for the treatment of erectile dysfunction. Sangkum P, Sirisopana K, Matang W, et al. Efficacy of the Orally Disintegrating Strip Sildenafil for the Treatment of Erectile Dysfunction: A Prospective, Randomized Trial. Sex Med 2021;9:100453.

Facing Counterfeit Medications in Sexual Medicine. A Systematic Scoping Review on Social Strategies and Technological Solutions

Introduction

The counterfeit phenomenon is a largely under-reported issue, with potentially large burden for healthcare. The market for counterfeit drugs used in sexual medicine, most notably type 5 phosphodiesterase inhibitors (PDE5i), is rapidly growing.

Aims

To report the health risks associated with the use of counterfeit medications, the reasons driving their use, and the strategies enacted to contain this phenomenon.

Methods

A systematic scoping review of the literature regarding counterfeit PDE5i was carried between January and June 2021, then updated in August 2021.

Main Outcome Measure

We primarily aimed to clarify the main drivers for counterfeit PDE5i use, the health risks associated, and the currently available strategies to fight counterfeiters.

Results

One hundred thirty-one records were considered for the present scoping review. Production of fake PDE5i is highly lucrative and the lacking awareness of the potential health risks makes it a largely exploitable market by counterfeiters. Adulteration with other drugs, microbial contamination and unreliable dosages make counterfeit medications a cause of worry also outside of the sexual medicine scope. Several laboratory techniques have been devised to identify and quantify the presence of other compounds in counterfeit medications. Strategies aimed at improving awareness, providing antitampering packaging and producing non-falsifiable products, such as the orodispersible formulations, are also described.

Clinical implications

Improving our understanding of the PDE5i counterfeit phenomenon can be helpful to promote awareness of this issue and to improve patient care.

Strengths & Limitations

Despite the systematic approach, few clinical studies were retrieved, and data concerning the prevalence of counterfeit PDE5i use is not available on a global scale.

Conclusion

The counterfeit phenomenon is a steadily growing issue, with PDE5i being the most counterfeited medication with potentially large harmful effects on unaware consumers.

Sansone A, Cuzin B, and Jannini EA. Facing Counterfeit Medications in Sexual Medicine. A Systematic Scoping Review on Social Strategies and Technological Solutions. Sex Med 2021;9:100437.

Development and In Vitro Evaluation of Controlled Release Viagra® Containing Poloxamer-188 Using Gastroplus™ PBPK Modeling Software for In Vivo Predictions and Pharmacokinetic Assessments

Sildenafil is the active substance in Viagra^® tablets, which is approved by the FDA to treat sexual dysfunction in men. Poor solubility and short half-life, however, can limit the span of its effectiveness. Therefore, this study focused on an oral controlled release matrix system with the aim to improve solubility, control the drug release, and sustain the duration of drug activity. The controlled release matrices were prepared with poloxamer-188, hydroxypropyl methylcellulose, and magnesium stearate. Various formulations of different ratios were developed, evaluated in vitro, and assessed in silico. Poloxamer-188 appeared to have a remarkable influence on the release profile of sildenafil citrate. In general, the rate of drug release decreased as the amount of polymer was gradually increased in the matrix system, achieving a maximum release period over 12 h. The in silico assessment by using the GastroPlus™ PBPK modeling software predicted a significant variation in C_max, t_max, t_1/2, and AUC_0-t among the formulations. In conclusion, the combination of polymers in matrix systems can have substantial impact on controlling and modifying the drug release pattern.

Sildenafil 4.0-Integrated Synthetic Chemistry, Formulation and Analytical Strategies Effecting Immense Therapeutic and Societal Impact in the Fourth Industrial Era

Sildenafil is a potent selective, reversible inhibitor of phosphodiesterase type 5 (PDE5) approved for the treatment of erectile dysfunction and pulmonary arterial hypertension. Whilst twenty years have passed since its original approval by the US Food and Drug Administration (USFDA), sildenafil enters the fourth industrial era catalyzing the treatment advances against erectile dysfunction and pulmonary hypertension. The plethora of detailed clinical data accumulated and the two sildenafil analogues marketed, namely tadalafil and vardenafil, signify the relevant therapeutic and commercial achievements. The pharmacokinetic and pharmacodynamic behavior of the drug appears complex, interdependent and of critical importance whereas the treatment of special population cohorts is considered. The diversity of the available formulation strategies and their compatible administration routes, extend from tablets to bolus suspensions and from per os to intravenous, respectively, inheriting the associated strengths and weaknesses. In this comprehensive review, we attempt to elucidate the multi-disciplinary elements spanning the knowledge fields of chemical synthesis, physicochemical properties, pharmacology, clinical applications, biopharmaceutical profile, formulation approaches for different routes of administration and analytical strategies, currently employed to guide the development of sildenafil-based compositions.

Efficacy and Safety of Mirodenafil Oro-Dispersible Film in Korean Patients with Erectile Dysfunction: A Double-Blind, Randomized, Placebo-Controlled, Parallel-Group, Multicenter, Phase IV Study

Purpose

To investigate the efficacy, safety, and tolerability of oro-dispersible film (ODF) formulation of mirodenafil 50 mg and 100 mg for the treatment of patients with erectile dysfunction (ED) in Korea.

Materials and Methods

A multicenter, randomized, double-blind, placebo-controlled, parallel-group study of 129 subjects was performed. Subjects were randomized to either placebo or mirodenafil ODF 50 mg or 100 mg to be taken in an “on demand” manner for 8 weeks. The primary efficacy variable was the International Index of Erectile Dysfunction (IIEF)-5 questionnaire. The secondary efficacy variables comprised Sexual Encounter Profile questions 2 and 3 (SEP2 and SEP3), the Global Assessment Question (GAQ), and the Life Satisfaction Checklist (LSC).

Results

IIEF-5 was significantly increased in all groups after treatment. However, compared to the placebo group, only the mirodenafil ODF 100 mg group showed a significant difference. SEP2 and SEP3 were increased in both mirodenafil groups; however, the increase was not statistically significant for SEP2. In terms of GAQ and LSC, the mirodenafil ODF groups showed significant increases compared with the baseline. Most treatment-associated adverse events were mild and resolved spontaneously.

Conclusions

Mirodenafil ODF is an effective and well-tolerated agent for the treatment of patients with ED in Korea.

Development and Characterization of an Orodispersible Film for Vitamin D3 Supplementation

Vitamin D plays a crucial and very well-known role in regulation of calcium homeostasis and bone metabolism and mineralization. However, a huge and more recent body of evidence supports the positive influence of vitamin D on the regulation of immune response, ranging from protection against respiratory tract infections to prevention and management of asthma. Nevertheless, vitamin D deficiency is a very common condition and there is an increasing need for suitable products for proper supplementation, allowing good compliance also in specific populations. Orally disintegrating tablets (ODT) were first developed to overcome the difficulty experienced by pediatric and geriatric patients of swallowing traditional oral dosage forms and, recently, orodispersible films (ODF) are gaining popularity as novel dosage form for assuming active pharmaceutical ingredients, vitamins, and ingredients for food supplements. This study describes a 2000 IU Vitamin D3 ODF for daily intake, consisting of hydrophilic polymers and suitable excipients, manufactured by film-casting process. Elongation-at-break (E%), Young’s modulus (Y), and tensile strength (TS) were investigated using a dynamometer. Chemical stability was evaluated assaying the vitamin D3 in the films stored at different environmental conditions. In addition, in vitro disintegration and dissolution studies were performed. Correlation existed between the mechanical properties of the film and the residual water, acting as plasticizer. The stability study showed that vitamin D3 assay was ≥90% also after 3 months at 40 °C. The film disintegrated in less than 1 min and the vitamin D3 released was ≥75% after 15 min. An ODF with suitable properties can be manufactured and used as innovative dosage form for vitamin D3 food supplements.

Drug delivery options and therapeutic advances in the management of erectile dysfunction

INTRODUCTION

Erectile dysfunction (ED) is defined as the inability to achieve or maintain an erection sufficient for satisfactory sexual performance. It is estimated that 20-30% of adult men will have at least one episode of ED during their lifetime and the prevalence increases with age. ED is known to have significant negative psychological implications for men, resulting in impaired functional status and a greater prevalence of anxiety and depression.

AREAS COVERED

Medications for the treatment of erectile dysfunction largely revolve around oral, injection, and topical therapies. Though all three modalities are widely used, each delivery option has its own advantages and specific indications. Likewise, there are several new developing treatments for ED that may change the landscape of treatment. The goal of this review is to summarize contemporary drug delivery options used in the treatment of ED and highlight future promising pharmacological developments.

EXPERT OPINION

There are a myriad of new developments on the horizon including new PDE5Is and drug targets, nanotechnology enhancements, stem cell and gene therapy, shockwave therapy, and platelet-rich plasma injections. These are all promising new methods to not only treat ED but also to address the pathology and prevent or eliminate further damage.

Sildenafil orodispersible film in the treatment of erectile dysfunction after radical prostatectomy: A single-centre open-label uncontrolled trial

Phosphodiesterase-5 inhibitors are the first-line therapy for erectile dysfunction (ED) after radical prostatectomy (RP). This single-centre open-label uncontrolled study evaluated the efficacy and safety of the new sildenafil orodispersible film (ODF) in ED treatment after RP. Sildenafil 100 mg ODF was administered twice a week for 3 months to patients under 75 years of age, with a Framingham cardiovascular risk score < 20% and a pre-operative International Index of Erectile Function (IIEF)-5 score ≥ 17, who had undergone open RP between 2016 and 2018. Erectile function was assessed pre-operatively, post-operatively and after treatment through the IIEF-5 score, the Sexual Encounter Profile Question (SEP-Q) 2 and SEP-Q3; adverse events (AE) were also investigated after 3 months. A total of 65 patients with a median (25th-75th percentile) post-operative IIEF-5 score of 8 (7-9) were treated. Nine (13.8%) patients reported AE of mild/moderate grade and discontinued treatment. A significant IIEF-5 score median (25th-75th percentile) increase of 10 (0-12) was found after treatment in the other 56 patients (p < .001). Sildenafil 100 mg ODF was effective in ED after RP in terms of improved IIEF-5 score and improved SEP-Q2 and SEP-Q3 in 67.9% of patients. It could represent a valid alternative for those patients with low compliance to tablet intake.

The Effect of Liver and Kidney Disease on the Pharmacokinetics of Clozapine and Sildenafil: A Physiologically Based Pharmacokinetic Modeling

Background and Objectives

Physiologically based pharmacokinetic (PBPK) modeling permits clinical scientists to reduce practical constraints for clinical trials on patients with special diseases. In this study, simulations were carried out to validate the pharmacokinetic parameters of clozapine and sildenafil using Simcyp^® simulator in young male adults and compare the effect of renal or hepatic impairment on the pharmacokinetic parameters of clozapine and sildenafil. Also, the effect of age on pharmacokinetic parameters of both drugs was investigated in healthy population and in patients with renal and hepatic impairment.

Methods

A full PBPK model was built in the simulator for clozapine and sildenafil based on physicochemical properties and observed clinical results. The model used was Advanced, Dissolution, Absorption and Metabolism (ADAM) for both drugs.

Results

The PBPK model adequately predicted the pharmacokinetic parameters of clozapine and sildenafil for the healthy adult population. In the simulation results, the bioavailability of both drugs was remarkably raised in both renal and hepatic impairment in young and elderly populations.

Conclusion

PBPK modeling could be helpful in the investigation and comparison of the pharmacokinetics in populations with specific disease conditions.

Physiologically Based Pharmacokinetic Modeling to Understand the Absorption of Risperidone Orodispersible Film

Objective

The aim of the present study was to investigate the absorption routes as well as the potential application of the oral transmucosal delivery of risperidone orodispersible film (ODF) using physiologically based pharmacokinetic modeling.

Methods

The pharmacokinetic study after intragastric (i.g.), supralingual, and sublingual administration of risperidone ODF was conducted in Beagle dogs. Then a mechanic absorption model which combined Oral Cavity Compartment Absorption and Transit (OCCAT) model with Advanced Compartment Absorption and Transit (ACAT) model for predicting the absorption routes of risperidone ODF in vivo was constructed using GastroPlus™. A sensitivity analysis was performed to investigate the impact of oral residence time on the in vivo absorption of risperidone ODF. Based on the fraction of intraoral absorption, the potential of the oral transmucosal delivery of risperidone were predicted.

Results

There were no statistical differences in the AUC_0-t (P = 0.4327), AUC_0-∞ (P = 0.3278), C_max (P = 0.0531), and T_max (P = 0.2775) values among i.g., supralingual, and sublingual administration of risperidone ODF in Beagle dogs. The predicted absorption percentage via oral mucosa at oral residence time of 2 min, 5 min, and 10 min was 7.0%, 11.4%, and 19.5%, respectively. No obvious difference was observed for the bioavailability of risperidone ODF within 10 min of oral residence time. The PBPK absorption model for risperidone could be simplified to include ACAT model solely.

Conclusion

The main absorption route for risperidone ODF was the gastrointestine. The absorption percentage via oral mucosa was almost negligible due to the physicochemical properties of risperidone although ODF dissolved completely in the oral cavity of Beagle dogs within 2 min.

Sample size determination in bioequivalence studies using statistical assurance

AIMS

Bioequivalence (BE) trials aim to demonstrate that the 90% confidence interval of the T/R-ratio of the pharmacokinetic metrics between two formulations (test [T] and reference [R]) of a drug is fully included in the acceptance interval [0.80, 1.25]. Traditionally, the sample size of BE trials is based on a power calculation based on the intrasubject variability coefficient of variation (CV) and the T/R-ratio of the metrics. Since the exact value of the T/R-ratio is not known prior to the trial, it is often assumed that the difference between the treatments does not exceed 5%. Hence, uncertainty about the T/R-ratio is expressed by using a fixed value for the sample size calculation. We propose to characterise the uncertainty about the T/R-ratio by a (normal) distribution for the log(T/R-ratio), with an assumed mean of  log θ = 0.00 (i.e. θ = 1.00) and a standard deviation σ_u , which quantifies the uncertainty. Evaluating this distribution leads to the statistical assurance of the BE trial.

METHODS

The assurance of a clinical trial can be derived by integrating the power over the distribution of the input parameters, in this case, the assumed distribution of the log(T/R)-ratio. Because it is an average power, the assurance can be interpreted as a measure of the probability of success that does not depend on a specific assumed value for the log(T/R)-ratio. The relationship between power and assurance will be analysed by comparing the numerical outcomes.

RESULTS

Using the assurance concept, values of the standard deviation for the distribution of potential log(T/R)-ratios can be chosen to reflect the magnitude of uncertainty. For most practical cases (i.e. when 0.95 ≤ θ ≤ 1.05), the sample size is not, or only slightly, changed when σ = |log(θ)|.

CONCLUSION

The advantage of deriving the assurance for BE trials is that uncertainty is directly expressed as a parameter of variability.

Needs and Expectations of Patients with Erectile Dysfunction: An Update on Pharmacological Innovations in Phosphodiesterase Type 5 Inhibition with Focus on Sildenafil

INTRODUCTION

Phosphodiesterase type 5 inhibitors (PDE5-Is) have an excellent efficacy and tolerability profile and remain the first-line choice for the treatment of erectile dysfunction (ED). However, ED is still an underdiagnosed and undertreated condition, and many men prematurely discontinue therapy with conventional dosage formulations despite successful intercourse.

AIM

To review the unmet needs and expectations of patients with ED and describe the latest pharmaceutical innovations in the field of PDE5-I formulations designed to address these needs, with particular reference to a new orodispersible film (ODF) formulation of the PDE5-I, sildenafil.

METHODS

Online literature search in PubMed and the Cochrane Library.

MAIN OUTCOME MEASURE

To identify English-language publications relevant to the aims of the present review.

RESULTS

Improved recognition and management of ED would enable the early diagnosis of underlying and comorbid conditions that contribute to ED, leading to improved patient health and health-related quality of life. To ensure successful outcomes and patient and partner satisfaction, the complex and personal issues that influence the patient's needs and expectations regarding treatment for ED must be considered along with their personal experiences and preferences. Innovative drug delivery systems, including orally disintegrating formulations, have been developed as alternatives to conventional dosage forms with the aim of improving patient convenience and acceptability and enhancing compliance. These alternative formulations include the sildenafil ODF, which is designed to improve acceptance and compliance over conventional solid dosage forms and extend the treatment options for men with ED by offering a convenient and discrete dosage form of a drug with proven efficacy.

CONCLUSION

The sildenafil ODF is an example of an innovative dosage formulation for ED that can be used interchangeably with the conventional film-coated formulation to better address the needs and expectations of men with ED. Jannini EA, Droupy S. Needs and Expectations of Patients with Erectile Dysfunction: An Update on Pharmacological Innovations in Phosphodiesterase Type 5 Inhibition with Focus on Sildenafil. Sex Med 2019;7:1-10.

Pharmacokinetics of a Novel Sildenafil Orodispersible Film Administered by the Supralingual and the Sublingual Route to Healthy Men

Background

Sildenafil was the first selective drug available on the market as oral therapy for erectile dysfunction (ED). A novel sildenafil orodispersible film (ODF) for ED treatment, containing sildenafil citrate, has recently been marketed.

Objectives

Study objective was to investigate sildenafil bioavailability of the novel ODF formulation after sublingual and supralingual administration.

Methods

In this randomised, two-way cross-over study, 12 healthy male volunteers received a single 50 mg sildenafil dose by the sublingual and supralingual administration routes. Plasma sildenafil was determined up to 12 h post-dose. Peak concentration (C_max) and area under concentration-time curve (AUC_0–t) were calculated and compared between the two administration routes by analysis of variance (ANOVA).

Results

Sublingual and supralingual administration can be claimed equivalent regarding the extent of sildenafil exposure since AUC_0–t 90 % CIs corresponded to 94.90–110.58% and were within the pre-specified acceptance range. C_max 90% CIs (79.92–125.57%) were only slightly outside the 80.00–125.00% limits, due to the small sample size, while the time to achieve C_max did not differ between treatments (p = 0.9277). Rate of exposure of the two administration routes was therefore similar. Reported treatment-related adverse events were mild to moderate headache (33.3% of subjects) and vomiting (8.3%).

Conclusions

In healthy men, sublingual and supralingual administration of sildenafil ODF resulted in a remarkably similar pharmacokinetic profile and confirmed the safety of both study treatments. The recently marketed sildenafil ODF, administered by both investigated routes, can provide a valuable alternative to the marketed solid oral forms (tablets) in ED treatment.

Enhanced Bioavailability of Tadalafil after Intranasal Administration in Beagle Dogs

Tadalafil is an oral selective phosphodiesterase type-5 inhibitor with demonstrated efficacy and safety that is used to treat erectile dysfunction. The purpose of this study is to compare the pharmacokinetic properties of tadalafil after conventional oral tablet administration and novel intranasal administration in beagle dogs. Fourteen 13-month-old male beagle dogs were randomly divided into two groups, and were given 5 mg tadalafil orally or intranasally in a parallel design. Blood samples were collected before and 0.5, 1, 1.5, 2, 4, 6, 8, 12, 24, and 36 h after administration. The plasma concentration of tadalafil was determined via liquid chromatography-tandem mass spectrometry (LC-MS/MS). The systemic exposure and absorption rate of tadalafil were significantly greater in the intranasal administration group than in the oral administration group. A one-compartment model with first-order absorption and elimination was sufficient to explain the pharmacokinetic characteristics observed after both oral and intranasal administration. This study indicates that the development of tadalafil nasal delivery systems is feasible and may lead to better results than the conventional oral route.

Comparative single-dose pharmacokinetics of sildenafil after oral and rectal administration in healthy beagle dogs

BACKGROUND

Sildenafil citrate, a highly selective phosphodiesterase type 5 inhibitor, is used to treat pulmonary hypertension (PH) in veterinary medicine. The objective of this study was to investigate pharmacokinetic profiles by oral administration of orally disintegrating film (ODF) and film coated tablet (FCT) formulations and rectal administration of ODF formulation in healthy dogs. Twelve healthy beagle dogs were administered four separate doses of sildenafil: FCT formulation 2 mg/kg orally, ODF formulation 2 mg/kg orally, ODF formulation 2 mg/kg rectally, and ODF formulation 10 mg/kg rectally. For 24 hours following administration, blood samples were collected and the plasma concentrations of sildenafil were assayed by liquid chromatography-tandem mass spectrometry.

RESULTS

There were no significant differences in all the pharmacokinetic parameters between FCT and ODF formulations when administrated orally. C_max at the time of rectal administration was lower when the same dose was given as that orally administered. No serious systemic adverse events (AEs) were observed.

CONCLUSIONS

These findings suggest that sildenafil ODF formulation can be used as an alternative to FCT formulation in the treatment of canine PH patients; additionally, rectal administration of sildenafil ODF may be a beneficial treatment option for canine patients who are unable to receive medication orally.

Comparison of tadalafil pharmacokinetics after administration of a new orodispersible film versus a film-coated tablet

Background

An orodispersible film (ODF) of tadalafil may provide increased convenience for erectile dysfunction (ED) patients as compared to conventional tablet formulations. In this study, we aimed to compare the pharmacokinetic, safety, and tolerability profiles of a newly developed ODF formulation of tadalafil to those of a film-coated tablet (FCT) of tadalafil.

Materials and methods

This study was conducted in healthy male subjects using an open-label, randomized sequence, two-period, two-formulation, single-dose, crossover design. The subjects were randomly assigned to one of two sequences of the two formulations: both the test drug (ODF) and the reference drug (FCT) contained 20 mg of tadalafil. Blood samples were collected up to 72 h after administration. Plasma concentrations of tadalafil were analyzed using liquid chromatography-tandem mass spectrometry. Geometric mean ratios (GMRs) of the ODF to FCT formulations and their 90% CIs for the pharmacokinetic parameters were estimated. Safety and tolerability were assessed throughout the study.

Results

Forty healthy male subjects were enrolled, and 36 of these completed the study. The GMRs (90% CIs) of the maximum plasma concentration and the area under the plasma concentration-time curve from time zero to the time of the last quantifiable concentration for tadalafil were 0.927 (0.882-0.974) and 0.972 (0.918-1.029), respectively. Both ODF and FCT formulations were well tolerated, and no clinically significant changes from the baseline were observed after dosing.

Conclusion

The pharmacokinetics of the tadalafil ODF formulation did not differ significantly from those of the FCT formulation. Furthermore, the safety and tolerability profiles of the ODF formulation were comparable to those of the FCT formulation. Therefore, this tadalafil ODF formulation offers a convenient treatment option for patients with erectile dysfunction.