Formulation and Optimization of Avanafil Biodegradable Polymeric Nanoparticles: A Single-Dose Clinical Pharmacokinetic Evaluation

From Oral to Sublingual: A Redefined Avanafil Tablet with a Breakthrough in Bioavailability and First-Pass Metabolism Avoidance

Introduction

Avanafil (AVA) is a very efficient phosphodiesterase type 5 inhibitor for the treatment of erectile dysfunction. However, it has limited bioavailability when taken orally and considerable first-pass metabolism. Enhancing its solubility and choosing an alternative delivery route may enhance its effectiveness and duration of action.

Methods

Eight complex formulations were elaborated and analyzed at various ratios using different polyethylene glycols and hydroxypropyl-beta-cyclodextrin (HP-β-CD). Sublingual tablets containing AVA were designed and optimized using the Quality-by-design approach. The tablets' pre-compression and post-compression properties were evaluated. The in-vivo pharmacokinetic behavior of the optimized tablet was assessed and compared with that of the commercial oral tablets in human volunteers.

Results

The HP-β-CD-AVA inclusion complex (1:1 molar ratio) showed an optimum solubilization capacity with an amount suitable for incorporation into sublingual tablets. The total amounts of superdisintegrants and Plasdone XL and the percentage of starch significantly influenced the length of time it took for 80% of the AVA to be released from the sublingual tablets, the tablet hardness, and the length of time for tablet disintegration. The optimized AVA sublingual tablet exhibited a 5.98-fold increase in the AVA mean residence time over the commercial tablet, with greater plasma exposure over 72 hours and 1356.42% relative bioavailability.

Conclusion

The sublingual tablets of the solubility-enhanced HP-β-CD-AVA inclusion complex represent a promising strategy to improve AVA bioavailability and bypass the first-pass effect. Furthermore, their extended activity offers potential clinical benefits, particularly for ED patients, such as ease of administration and reduced side effects.

Nanotechnology-based drug delivery platforms for erectile dysfunction: addressing efficacy, safety, and bioavailability concerns

Erectile dysfunction (ED), is a common and multidimensional sexual disorder, which comprises changes among any of the processes of the erectile response such as organic, relational, and psychological. However, both endocrine and nonendocrine causes of ED produce substantial health implications including depression and anxiety due to poor sexual performance, eventually affecting man's life eminence. Marginally invasive interventions following ED consist of lifestyle modifications, oral drugs, injections, vacuum erection devices, etc. Nevertheless, these conventional treatment regimens follow certain drawbacks such as efficacy and safety issues, and navigate to the development of novel therapeutic approaches such as nanomedicine for ED management. Nanotechnology-centred drug delivery platforms are being explored to minimize these limitations with better in vitro and in vivo effectiveness. Moreover, nanomedicine and nanocarrier-linked approaches are rapidly developing science in the nanoscale range, which contributes to site-specific delivery in a controlled manner and has generated considerable interest prominent to their potential to enhance bioavailability, decrease side effects, and avoidance of first-pass metabolism. This review provides an overview of recent discoveries regarding various nanocarriers and nano-delivery methods, along with current trends in the clinical aspects of ED. Additionally, strategies for clinical translation have been incorporated.

Incorporating sodium deoxycholate endorsed the buccal administration of avanafil to heighten the bioavailability and duration of action

The highly effective phosphodiesterase type 5 inhibitor (avanafil; AVA) is routinely prescribed to treat erectile dysfunction. The drug has poor oral bioavailability and undergoes a significant first-pass metabolism. Therefore, altering AVA's solubility and choosing a different delivery method may boost its effectiveness. Nine different solid dispersion formulations utilizing polyvinylpyrrolidone (PVP) at three different ratios were prepared and characterized. The Box-Behnken design was employed to optimize AVA-buccal tablets. The pre-compression and post-compression characteristics of the tablets were assessed. The mucoadhesion strength of the optimized tablet was investigated using cow buccal mucosal tissue. In vivo performance of the optimized tablets was examined on human volunteers compared to the commercial tablets. PVP K90 at 2:1 drug to polymer ratio showed the highest solubilization capacity. The mucoadhesive polymer type and percentage and the mucopenetration enhancer percentage were significantly affect the mucoadhesion strength, tablet hardness, and the initial and cumulative AVA released from the prepared tablets. The optimized AVA-buccal tablet showed 4.96 folds increase in the mean residence time, higher plasma exposure, and an improvement in the relative bioavailability of AVA by 1076.27% compared with the commercial tablet. Therefore, a successful approach to deal with AVA first-pass metabolism and low bioavailability could be to employ buccal tablets containing a solubility-enhanced form of AVA.

Advances in Nanoparticle Delivery System for Erectile Dysfunction: An Updated Review

INTRODUCTION

The use of current available treatment for male erectile dysfunction (ED) has some limitations that are related to efficacy and adverse effects. Nanotechnology has been used as a new tool in medicine to improve these limitations and new medications potentially to alleviate and cure ED.

AIM

To review the currently literature on new nano medications for ED based on scientific and clinical studies, efficacy, safety, mechanisms of action, and to identify gaps for future research.

METHODS

A comprehensive literature review was conducted via Google Scholar, Science Direct, and PubMed on English publications using different keywords such as "erectile dysfunction", "emerging treatments", "nanotechnology", and "herbal medicine". The retrieved papers were organized into groups according to the sections covered in this review paper.

MAIN OUTCOMES MEASURES

We reviewed novel ED treatments such as nanotechnological phosphodiesterase inhibitors, papaverine hydrochloride, sialorphin, adipose tissue-derived stem cells, sonic hedgehog, and herbal medicine.

RESULTS

Numerous preclinical studies have addressed novel phosphodiesterase 5 inhibitors nanoparticle, and their recent delivery systems. Nitric oxide, sialorphin, sonic hedgehog, and herbal medicine loaded nanoparticles and nano adipose tissue-derived stem cells as a potential new treatment for ED. In addition, papaverine-containing nanoparticles have been reported. A limited number of randomized clinical studies have determined the mechanism of these treatments.

CONCLUSION

A literature review on the application of nanotechnology in ED therapy was successfully conducted. New nano medications are promising to treat ED. However, further studies are warranted to further assess their efficacy and safety. Masuku NP, Unuofin JO, Lebelo SL. Advances in Nanoparticle Delivery System for Erectile Dysfunction: An Updated Review. Sex Med 2021;XX:XXXXXX.

Investigating the Potential of Transdermal Delivery of Avanafil Using Vitamin E-TPGS Based Mixed Micelles Loaded Films

To avoid the first-pass metabolism of avanafil (AVA) and its altered absorption in the presence of food after oral administration, this study aimed to investigate the potential of TPGS-based mixed micelle (MM)-loaded film for transdermal delivery and the enhancement of bioavailability. A Box-Behnken design was employed to optimize the permeation behavior of AVA from the transdermal film across the skin. The variables were the hydrophile-lipophile balance (HLB) of the surfactant (X₁), the concentration of mixed micelles (MMs) in the film (X₂), and the concentration of the permeation enhancer (X₃). The initial permeation of AVA after 1 h (Y₁), and the cumulative permeation of AVA after 24 h (Y₂) were the dependent variables. Ex vivo studies were carried out on freshly isolated rat skin to investigate the drug's permeation potential and results were visualized using a fluorescence laser microscope. Moreover, the pharmacokinetic behavior after a single application on male Wistar rats, in comparison with films loaded with raw AVA, was evaluated. The results showed that the optimum factor levels were 9.4% for the HLB of the surfactant used, and 5.12% MMs and 2.99% penetration enhancer in the film. Imaging with a fluorescence laser microscope indicated the ability of the optimized film to deliver the payload to deeper skin layers. Furthermore, optimized AVA-loaded TPGS-micelles film showed a significant increase (p < 0.05) in the C_max of AVA and the area under the AVA plasma curve (approximately three-fold). The optimized AVA-loaded TPGS-MM film thus represents a successful delivery system for enhancing the bioavailability of AVA.

Repurposing of Sitagliptin- Melittin Optimized Nanoformula against SARS-CoV-2: Antiviral Screening and Molecular Docking Studies

The outbreak of the COVID-19 pandemic in China has become an urgent health and economic challenge. The objective of the current work was to evaluate the efficacy of the combined complex of Sitagliptin (SIT) with melittin (MEL) against SARS-CoV-2 virus. SIT-MEL nano-conjugates were optimized by a full three-factor bi-level (23) factorial design. In addition, SIT concentration (mM, X1), MEL concentration (mM, X2), and pH (X3) were selected as the critical factors. Particle size (nm, Y1) and zeta potential (mV, Y2) were assessed as responses. Characterization of the optimized formula for Fourier-transformed infrared (FTIR) was carried out. The optimized formula showed particle size and zeta potential values of 77.42 nm and 27.67 mV, respectively. When compared with SIT and MEL, the combination of SIT-MEL complex has shown anti-viral potential against isolate of SARS-CoV-2 with IC50 values of 8.439 μM with significant improvement (p < 0.001). In addition, the complex showed IC50 in vitro 3CL-protease inhibition with IC50 7.216 µM. Molecular docking has revealed that formula components have good predicted pocket accommodation of the SARS-CoV-2 3-CL protease. An optimized formulation of SIT-MEL could guarantee both enhanced delivery to the target cells and the enhanced cellular uptake with promising activities against SARS-CoV-2.