Enhanced Dissolution of Sildenafil Citrate Using Solid Dispersion with Hydrophilic Polymers: Physicochemical Characterization and In Vivo Sexual Behavior Studies in Male Rats

Abstract

Sildenafil citrate (SLC) is a frequently used medication (Viagra®) for the treatment of erectile dysfunction (ED). Due to its poor solubility, SLC suffers from a delayed onset of action and poor bioavailability. Hence, the aim of the proposed work was to prepare and evaluate solid dispersions (SDs) with hydrophilic polymers (Kolliphor® P188, Kollidon® 30, and Kollidon®-VA64), in order to enhance the dissolution and efficacy of SLC. The SLC-SDs were prepared using a solvent evaporation method (at the ratio drug/polymer, 1:1, w/w) and characterized by Differential Scanning Calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscope (SEM), drug content, yield, and in vitro release studies. Based on this evaluation, SDs (SLC-KVA64) were optimized, with a maximum release of drug (99.74%) after 2 h for all the developed formulas. The SDs (SLC-KVA64) were further tested for sexual behavior activity in male rats, and significant enhancements in copulatory efficiency (81.6%) and inter-copulatory efficiency (44.9%) were noted in comparison to the pure SLC drug, when exposed to the optimized SLC-KVA64 formulae. Therefore, SD using Kollidon®-VA64 could be regarded as a potential strategy for improving the solubility, in vitro dissolution, and therapeutic efficacy of SLC.

Green Synthesized Silver Nanoparticles Using Tridax Procumbens for Topical Application: Excision Wound Model and Histopathological Studies

“…The sample under investigation was coated with a thin layer of gold-palladium by sputter. The image was zoomed and particles were analyzed to determine the morphology of the synthesized AgNPs [25].…”

“…TGA study of AgNPs represents thermal stability and composition. [25]. "Netzsch analyzing thermomicro balance" was used to measure the change of mass for AgNPs (sample) as a function of temperature under the controlled environment of heating rate 10 • C/min), gas atmosphere (nitrogen).…”

Application of hydrophilic polymers for the preparation of tadalafil solid dispersions: micromeritics properties, release and erectile dysfunction studies in male rats

“…The most significant improvement in dissolution rate was observed in TK188 SD, which demonstrated a 2.96 fold increase in the dissolution percentage compared to pure TFL. The highest dissolution percentage of TK188 could be due to Kolliphor ® P188 wetting property, micelle formation at critical micelle concentration with hydrophilic surfaces and lipophilic core dramatically improved the solubility of hydrophobic TFL drug ( Aldawsari et al, 2021 ). Model dependent kinetic equations were fitted with the dissolution data, and the regression parameters were calculated to analyze the type of drug release from binary SDs.…”

“…In previous studies, the polymers used to develop solid dispersions of tadalafil were polyvinylpyrrolidone (PVP) ( Al-Shdefat et al, 2019 ), methylcellulose (MC), Hydroxypropyl methylcellulose (HPMC), PVP-vinyl acetate (PVP-VA) copolymer, Kollicoat IR and Soluplus ® ( Wlodarski et al, 2015 ), tartaric acid and Soluplus ® ( Aldawsari et al, 2021 ), tartaric acid and PVP/VA S-630 ( Choi et al, 2017b ), malic acid and PVP/VA S-630 ( Choi & Park, 2017 ) and Kollidon ® 12 PF, Kollidon ® VA 64, and Soluplus ® ( Slámová et al, 2020 ) were used to prepare SDs of TFL. The use of Kollidon ® 12 PF, Kollidon ® VA 64, and Soluplus ® to develop SDs of TFL using solvent evaporation, hot-melt extrusion, and spray drying revealed an enhanced dissolution profile exhibited by a formulation containing both Kollidons and the drug release was retarded due to the presence of soluplus ® due to increased swelling of hydrophilic polymers with an increase in molecular weight during the dissolution ( Slámová et al, 2020 ).…”

Special Issue on “Function of Polymers in Encapsulation Process”

“…In the last study, three hydrophilic polymers, namely Kolliphor ® P188, Kollidon ® 30, and Kollidon ® -VA 64 (obtained from BASF Co., Ludwigshafen, Germany) were employed as drug carriers through solid dispersion (SD) approach to encapsulate Sildenafil citrate, a frequently used medication (under the brand name Viagra) for the treatment of erectile dysfunction (ED). The authors concluded that the optimized SD system exhibited superior activity and was a promising strategy for improving solubility, dissolution rate, and aphrodisiac effects on male rats [ 5 ].…”