Polyvinylpyrrolidone Concentration Research Articles

Enhanced photocatalytic reduction of p-nitrophenol by polyvinylpyrrolidone-modified MOF/porous MgO composite heterostructures

Catalysts derived from Metal-Organic Frameworks (MOF) present a compelling blend of cost-effectiveness and superior performance in reduction reactions. In this study, polymer-decorated MOF-Cobalt (MOF-Co) was deposited onto porous magnesium oxide (MgO) layers, acquired through surface modification of AZ31 Mg alloy via plasma-assisted oxidation, with the aim of fabricating novel catalysts for reduction reactions. Herein, this synthesis involved the utilization of Cobalt-benzene dicarboxylic acid (Co-BDC), where cobalt ions served as metal nodes and 1,4-benzene dicarboxylic acid (H2BDC) functioned as an organic linker, with and without the presence of polyvinylpyrrolidone (PVP) as an active site enhancer. The morphology of the prepared catalysts was affected by several factors such as pH, hydrothermal treatment duration, PVP content, and the presence of a MgO layer. The optimal catalyst, designated as metal-organic frameworks-cobalt at 80 °C temperature and 1 h of hydrothermal treatment at pH 4 (MOF-Co 1.4), was synthesized on the MgO layer using a solution containing 1.7 g of PVP, H2BDC, and Co(NO₃)₂.6H₂O. The paper-like morphology of the MOF-Co 1.4 catalyst facilitated exceptional performance, efficiently degrading p-nitrophenol (p-NP) under visible light irradiation with an impressive 99.74 % efficiency within just 5 min of exposure, while also demonstrating stability over five successive cycles. ·O2− species was found to drive the reduction reaction to p-aminophenol, with harmless compounds as byproducts, while GC-MS analysis identified intermediates in the reduction of p-NP. Density functional theory (DFT) calculations suggested that H2BDC and PVP jointly provided multi-active sites, enabling effective contact with reactants and rapid electron transfer, thus playing a synergistic role in the catalytic reduction process. This study pioneers a novel method for designing efficient bulk catalysts, achieving high efficiency and stability in pollutant degradation with fast, low-energy fabrication.

Rapid Fabrication of Tungsten Oxide-Based Electrochromic Devices through Femtosecond Laser Processing

The sol-gel method is a widely adopted technique for the preparation of tungsten trioxide (WO₃) materials, favored for its cost-effectiveness and straightforward production procedures. However, this method encounters challenges such as prolonged annealing periods and limited flexibility in fabricating patterned WO₃ films. This study introduces a novel approach that integrates femtosecond laser processing with the sol-gel method to enhance the fabrication of WO₃ films. By adjusting polyvinylpyrrolidone (PVP) concentrations during sol-gel synthesis, precise control over film thickness and optimized film properties were achieved. The innovative technique significantly reduced the annealing time required to achieve an 80% transmittance rate from 90 min to 40 min, marking a 56% decrease. Laser processing increased the surface roughness of the films from Sa = 0.032 to Sa = 0.119, facilitating enhanced volatilization of organics during heat treatment. Additionally, this method improved the transmittance modulation of the films by 22% at 550 nm compared to unprocessed counterparts. This approach not only simplifies the manufacturing process but also enhances the optical efficiency of electrochromic devices, potentially leading to broader applications and more effective energy conservation strategies.

Colyophilized Sugar-Polymer Dispersions for Enhanced Processing and Storage Stability.

Sucrose and trehalose pharmaceutical excipients are employed to stabilize protein therapeutics in a dried state. The mechanism of therapeutic protein stabilization is dependent on the sugars being present in an amorphous solid-state. Colyophilization of sugars with high glass transition polymers, polyvinylpyrrolidone (PVP), and poly(vinylpyrrolidone vinyl acetate) (PVPVA), enhances amorphous sugar stability. This study investigates the stability of colyophilized sugar-polymer systems in the frozen solution state, dried state postlyophilization, and upon exposure to elevated humidity. Binary systems of sucrose or trehalose with PVP or PVPVA were lyophilized with sugar/polymer ratios ranging from 2:8 to 8:2. Frozen sugar-PVPVA solutions exhibited a higher glass transition temperature of the maximally freeze-concentrated amorphous phase (Tg') compared to sugar-PVP solutions, despite the glass transition temperature (Tg) of PVPVA being lower than PVP. Tg values of all colyophilized systems were in a similar temperature range irrespective of polymer type. Greater hydrogen bonding between sugars and PVP and the lower hygroscopicity of PVPVA influenced polymer antiplasticization effects and the plasticization effects of residual water. Plasticization due to water sorption was investigated in a dynamic vapor sorption humidity ramping experiment. Lyophilized sucrose systems exhibited increased amorphous stability compared to trehalose upon exposure to the humidity. Recrystallization of trehalose was observed and stabilized by polymer addition. Lower concentrations of PVP inhibited trehalose recrystallization compared to PVPVA. These stabilizing effects were attributed to the increased hydrogen bonding between trehalose and PVP compared to trehalose and PVPVA. Overall, the study demonstrated how differences in polymer hygroscopicity and hydrogen bonding with sugars influence the stability of colyophilized amorphous dispersions. These insights into excipient solid-state stability are relevant to the development of stabilized biopharmaceutical solid-state formulations.

Boosting the photocatalytic activity of bismuth vanadate (BiVO4) via optimization of the internal polarization

Photocatalytic performance can be improved by optimizing the morphology and surface texture of the photocatalyst or forming different p-n and/or n-n heterojunctions. Although the heterojunction system enhances photocatalytic property; however, an internal spontaneous polarization electric field may be much more effective due to the separation of electron-hole pairs when the polarization field forces them to move in different directions. The present study demonstrated this insight where the BiVO4 synthesis condition and polarization field forces were controlled via homogeneous precipitation in the presence of polyvinylpyrrolidone (PVP). The as-synthesized BiVO4 photocatalysts' structure and morphology were investigated using XRD, SEM, Raman, DRS, and PL. The result revealed that the increase of PVP concentration reformed the shaping to the truncated bipyramid-like shape and creates a spontaneous internal polarization that enhanced BiVO4 photocatalytic performance. The photocatalytic activity of BiVO4 was evaluated by monitoring the photocurrent enhancement using chronoamperometry, electrochemical impedance spectra and the photodegrading of methylene blue (MB) aqueous solution to harmless compounds in the presence of light. The spontaneous polarization between the different facets of BiVO4 crystal enhances the e−/h+ separation during internal facets homojunction and leads to four times photocurrent enhancement and the MB photocatalytic degradation rate increased from 0.43 to 1.92 min−1.

Synergistic effects of polyvinylidene fluoride (PVDF) and polyvinylpyrrolidone (PVP) blends in gel electrolytes for efficient and long-term stability in dye-sensitized solar cells (DSSCs)

In this work, the stability issues associated with liquid electrolyte-based dye-sensitized solar cells (DSSC) have been addressed by introducing polymer gel electrolytes. The synergistic combination of polyvinylidene fluoride (PVDF) and polyvinylpyrrolidone (PVP) has been achieved through solution blending. Ionic conductivity measurements, scanning electron microscopy, X-ray diffraction analysis, and Fourier transform infrared spectroscopy have been employed for analysis. Optimal cohesiveness was observed at PVP concentrations exceeding 40 %, with the best outcomes achieved at a 50 % PVDF-PVP weight ratio. The electrolyte solution, comprising the polymer blend, suitable solvents, and iodine-based salts, exhibits peak conductivity (2.33 mScm⁻1) at a 10 % salt content. DSSCs utilizing the PVDF & PVP polymer blend gel electrolytes demonstrate enhanced durability and maintained efficiency at 5.43 %, exhibiting only a modest 12 % reduction compared to liquid electrolyte counterparts. Over two weeks, the fabricated DSSCs exhibited consistent photovoltaic performance, while conventional cells experienced significant declines in short-circuit current (36 %) and open-circuit voltage (33.33 %). This study signifies a promising advancement in solar cell technology, showcasing improved stability and performance in DSSCs using conductive polymer blend gel electrolytes.

Effect of polyvinylpyrrolidone concentration on optical properties of CuCrO2 thin films

In this study, CuCrO2 thin films were fabricated by spin-coating technique on alkali-free glass substrates and a two-step annealing process. The copper-based delafossite CuCrO2 is a p-type transparent conductive oxide that exhibits a wide energy bandgap and excellent stability. To improve the transmittance of CuCrO2 thin films, polyvinylpyrrolidone (PVP) was used as a porogen for preparing thin films with high transmittance and high haze values. The highest transmittance of 73.75% was achieved with 0.5 g of PVP. The bandgaps of prepared CuCrO2 thin films were estimated at 2.82 eV to 3.11 eV. The prepared CuCrO2 thin films had a porous structure and high transmittance. The high potential transmittance of porous CuCrO2 thin films makes them applicable to photovoltaic systems, transistors and touch screens or displays in the future.

Acceleration of the electron transfer for efficient photocatalytic hydrogen evolution via regulating the surfactant around the active center in 2D MOFs

Although surfactants have been proved to be effective in controlling the size and morphology to prepare high-quality two-dimensional (2D) MOF nanosheets, the impact of surfactants remaining on the 2D MOF nanosheets on their microenvironment is rarely reported. In this paper, polyvinylpyrrolidone (PVP) was used as surfactant to synthesize Co-TCPP(Pd) (abbreviated as Co-Pd) nanosheets, and the content of PVP attached to Co-Pd nanosheets was controlled by ethanol treatment, to regulate the microenvironment around Co-Pd nanosheets. The XRD, FT-IR, XPS, TEM, and TG were used to confirm that after ethanol ultrasonic treatment, the PVP content on Co-Pd nanosheets was gradually reduced without damaging the original structure and morphology of Co-Pd nanosheets. PVP attached to Co-Pd nanosheets will slow down the electron migration rate, affecting the microenvironment around co-catalyst Pd, which has been confirmed by EIS, PL and DFT etc. The results exhibited that the Co-Pd-6 obtained by ethanol ultrasonic treatment 6 times showed the more excellent photocatalytic hydrogen evolution activity (8284.25 umol·g−1·h−1), which was 4.02 times as that of Co-Pd-0 (2059.59 umol·g−1·h−1) without ethanol ultrasonic treatment), indicating that PVP will have a negative impact on the microenvironment around the co-catalyst, thereby affecting the photocatalytic hydrogen evolution performance. This study indicates that efficient photocatalytic hydrogen evolution can be achieved via adjusting the microenvironment around the co-catalyst to promote electron transfer.

Comparison of the Properties and Structure of Montmorillonites Modified with Polyvinylpyrrolidone

The modification method of aluminosilicate clays and the modifier content have a decisive influence on the structure and properties of the obtained nanocomposites. Therefore, the development and research of new techniques of nanoclays modification are of great importance for polymer nano-chemistry. The work studied the modification of montmorillonite (MMT) using polyvinylpyrrolidone (PVP) in an aqueous colloidal solution with the subsequent separation of three separate fractions of the solution according to the previously developed method. The influence of the initial mass ratio of components (MMT/PVP) on the structure and thermal properties of the modified MMT in each solution layer was determined. Scanning electron microscopy (SEM), X-ray diffraction (XRD), thermal gravimetry (TG), differential scanning calorimetry (DSC), and Fourier-transform infrared (FTIR) spectroscopy were used for research. It was established that the mass ratio of components in the initial solution has almost no effect on the structure of MMT in the top and middle solution layers, but significantly affects the yield of final products. Different structures can be obtained in the bottom layer of the solution. Still, intercalated MMT was obtained exclusively at the mass ratio of MMT/PVP = 1:2. In addition, the work investigated the structure and thermal properties of modified montmorillonites with the same PVP content, and it has been proven that such composites have dissimilar structures and properties when obtained by different methods.

A sub-10 nm polyamide nanofiltration membrane from polyvinylpyrrolidone-mediated interfacial polymerization

In conventional interfacial polymerization (IP) for thin-film composite nanofiltration membranes, the separation layer is typically thick (∼100 nm), which limits its water permeance. In this study, we successfully synthesized an ultrathin polyamide layer (∼8.6 nm) from polyvinylpyrrolidone (PVP)-mediated IP. With the surfactant concentration over its critical micelle concentration, PVP not only formed a monolayer at the water-heptane interface, but also stayed in the aqueous solution. The CO groups of PVP formed the N–H⋯O hydrogen bond interactions with N–H bonds of piperazine (PIP) monomers in the aqueous phase to slow down the diffusion of PIP monomers. Besides, PVP with amphiphilic groups minimized the interfacial tension at the water-heptane interface to regulate IP processes. By adjusting the concentration of PVP, we obtained a sub-10 nm polyamide nanofiltration membrane. Moreover, hydrophilic PVP macromolecules improved the membrane surface hydrophilicity. Due to the ultrathin thickness and improved hydrophilicity, the optimized polyamide membrane demonstrated a threefold increase in permeance compared to that of the pristine polyamide membrane without PVP addition, and maintained 98.4% rejection for 1000 ppm Na2SO4 solution. This study provides a new insight into fabricating sub-10 nm polyamide membranes for nanofiltration processes.

Refinement of Nanoporous Cu by Polyvinylpyrrolidone and Photodegradation of Methyl Orange by Cu2O Nanowires and Nanoporous Cu Photocatalysts

Refinement of nanoporous Cu (NP Cu) by the addition of Polyvinylpyrrolidone (PVP) in HF solution during dealloying of Ti40.6Zr9.4Cu40.6Ni6.3Sn3.1 amorphous ribbons and effect of the surface coverage of Cu2O nanowires obtained by immersing NP Cu in dehydrated ethanol on the photodegradation of methyl orange (MO) pollutants were investigated. The sizes of pores and ligaments of NP Cu decrease significantly with the increase of PVP concentration in the dealloying solutions, accompanied by a drastic decrease in the surface diffusivity and the dislocation defect densities. The surface coverage of Cu2O nanowires becomes higher with an increase of the PVP reagents. The Cu2O nanowires@nanoporous Cu (Cu2O@NP Cu) catalysts show excellent photocatalytic activity towards the degradation of MO under the sunlight due to the existence of large amounts of heterojunctions between Cu2O nanowires and Cu ligaments in nanoscale.

Formulation of Graphene Nanoplatelets Water-Based Nanofluids using Polyvinylpyrrolidone (PVP) as Surfactant

Graphene nanoplatelets (GNP) have garnered significant interest owing to their remarkable mechanical properties, making them ideal materials for enhancing the heat transfer properties of nanofluids. However, the agglomeration of GNP in water-based nanofluids remains a significant challenge, limiting their practical applications. In this study, a comprehensive investigation into the formulation of water-based nanofluids using GNP is presented, with a focus on the incorporation of polyvinylpyrrolidone (PVP) as a surfactant to enhance their stability and dispersion. The nanofluid formulations were systematically prepared with varying concentrations of GNP and PVP to optimize their thermal properties. Additionally, the thermal conductivity and viscosity of the nanofluids were examined over a range of temperatures and concentrations. The results show that the formulation of GNP with 0.6 wt.% shows great potential as a nanofluid with 0.6611 W/mK and 1.22 mPa.s for thermal conductivity and viscosity, respectively. The findings also demonstrate that the incorporation of PVP significantly improves the stability and dispersion of GNP in water, leading to enhanced thermal conductivity and manageable viscosity. These findings contribute to the application of this nanofluid in various industries, specifically solar energy.

Technology for Biobanking of Epididymal Spermatozoa from Patient with Obstructive Azoospermia: Case Report about Baby Born after Conventional Freezing Only with a Nonpermeable Cryoprotectant 360 kDa Polyvinylpyrrolidone.

This publication reports, for the first time, the birth of a healthy child after intracytoplasmic sperm injection (ICSI) of motile spermatozoa after conventional ("slow") freezing of epididymal spermatozoa using 5% polyvinylpyrrolidone (PVP) of high molecular weight (360 kDa). Cryopreservation solution with 10% PVP was added to 30 µL of spermatozoa suspension in a 1:1 ratio, with a final PVP concentration of 5%. Then, polycarbonate capillaries for oocyte denudation with a diameter of 170 µm were filled with 60 µL of the resulting sperm suspension. After that, the capillaries were placed for 10 minutes at a height of 15 cm above liquid nitrogen and immersed into liquid nitrogen. To warm the spermatozoa, the capillaries were immersed in a water bath at a temperature of 40°C for 30 seconds. Oocyte fertilization was performed by ICSI. Zygotes were cultured in vitro for 5 days to the blastocyst stage. More than 100 spermatozoa were obtained after percutaneous epidydimal sperm aspiration, of which 80% were motile. After cryopreservation, storage for 3 months in liquid nitrogen, and thawing, 72% of the total sperm cells remained motile. Ten oocyte-cumulus complexes were found after follicle puncture, and eight metaphase II stage oocytes were fertilized using ICSI. After 18 hours, two pronuclei were found in seven (88%) of the oocytes. An analysis of the morphological characteristics of 5-day-old embryos showed that four (57%) of them reached the blastocyst stage. One embryo was transferred, and the remaining embryos were cryopreserved (vitrified). The onset of pregnancy was detected on the 14th day after embryo transfer, and one healthy girl (3300 g) was born at term.

Evaluation of the physical properties of andaliman (Zanthoxylum acanthopodium DC) fruit extract tablets using polyvinylpyrrolidone as a binder agent

Background: Zanthoxylum acanthopodium DC, also known as andaliman, is a traditional herb utilized predominantly as a spice. It is rich in bioactive compounds such as alkaloids, flavonoids, tannins, saponins, and terpenoids, which exhibit analgesic activities.
 Objective: This study aims to develop a tablet formulation of andaliman fruit extract, employing polyvinyl pyrrolidone (PVP) K-30 as a binder, utilizing the wet granulation method.
 Method: The andaliman fruit was processed to extract its components using 96% ethanol. The extract, at a concentration of 100 mg, was then formulated into three different tablet formulations, varying in PVP K-30 concentration: F1 (1%), F2 (3%), and F3 (5%). These formulations were analyzed for granule characteristics and physical properties of the tablets.
 Results: Granule testing confirmed that all formulations met the requirements for quality granules. Among the formulations, F1 (1% PVP concentration) demonstrated superior physical properties: size uniformity of 1.22±0.00 cm, weight uniformity of 518.53±10.15 mg, friability of 0.45±0.01%, hardness of 6.34±0.05 kg, and disintegration time of 9.42±0.90 minutes.
 Conclusion: The tablet formulation of Andaliman fruit extract with 1% PVP K-30 exhibited the most favorable physical properties, suggesting its potential viability for further development and testing. This study lays the groundwork for exploring Andaliman fruit-based analgesic tablets.

FORMULATION, ANALYSIS AND VALIDATION OF NANOSUSPENSIONS-LOADED VORICONAZOLE TO ENHANCE SOLUBILITY

Objective: This study aimed to enhance the solubility of voriconazole (VRZ) via loading to nanosuspensions using solvent/anti-solvent technique. The optimisation of independent variables (polymer concentrations) was carried out to achieve the desired particle size and maximise the percentage of entrapment efficiency (EE %) and drug loading (DL %) using design-expert®software. Methods: Design-Expert® software, version 13, was used to design and optimise nanosuspensions-loaded VRZ using 23 factorial designs. Concentrations of polyvinylpyrrolidone, hydroxypropyl methylcellulose and poloxamers were selected as independent variables to achieve ideal particle size, polydispersity index (PDI), entrapment efficacy (EE %) and drug loading (DL %). Atomic force microscopy (AFM), differential scanning calorimetry (DSC) and saturated solubility were used to assess the lyophilized nanoparticles. The compatibility between the drug and the polymers was studied using Fourier transform infrared spectroscopy (FTIR). Results: The particle size, PDI, EE %, and DL % were in the range of 15.6–145.6 nm, 0.010-0.120, 55.9 %-91.9 %, and 6.68-36.76 %, respectively. The saturated solubility of nanosuspensions-loaded VRZ (NS-VRZ) relative to free VRZ was increased tenfold in DW and twelvefold in PBS (pH 7.4). DSC thermogram confirmed the incorporation of VRZ in the nanosuspensions. The AFM of NS-VRZ validated spherical tiny particle size with a smooth surface. There is no chemical interaction between VRZ and the polymers, according to an FTIR investigation. Conclusion: The solubility of VRZ was successfully enhanced by loading to nanosuspensions. The solvent/anti-solvent technique was proven to be cost-effective, easy to operate and suitable for the preparation of NS-VRZ using Design-Expert®software.

Three-dimensionally printable hollow silica nanoparticles for subambient passive cooling

Abstract Solar reflectance and thermal emissivity are critical benchmarks for evaluating the effectiveness of passive cooling strategies. The integration of three-dimensional (3D) printing techniques with passive cooling materials enables local thermal management of multifaceted objects, offering opportunities for unexplored energy-saving applications. For example, conformal printing of cooling materials can mitigate solar absorption caused by the top metal electrodes in solar cells, thereby improving their efficiency and lifetime. In this study, we report the synthesis of 3D printable hollow silica nanoparticles (HSNPs) designed to induce subambient cooling performance under daylight conditions. HSNPs with diameters of 400–700 nm and silica shell thicknesses of approximately 100 nm were synthesized using an in-situ sol–gel emulsion method. Subsequently, these HSNPs were formulated into printable pastes by carefully selecting the mixture concentration and molecular weight of polyvinylpyrrolidone (PVP). The PVP-linked HSNPs exhibited a solar (0.3–2.5 μm) reflectivity of 0.98 and a thermal (8–13 μm) emissivity of 0.93. In contrast to a single silica nanoparticle (NP), the scattering analysis of a single HSNP revealed a distinctive scattering distribution characterized by amplified backward scattering and suppressed forward scattering. In outdoor daytime experiments, the HSNP-printed sample led to the subambient cooling of a dielectric substrate, surpassing the cooling performance of reference materials such as silica NPs, silver pastes, and commercial white plastics and paints.

Determination of Morphine Using Carboxylated Multiwalled Carbon Nanotubes (MWCNTs) as the Label for an Immunochromatographic Assay (ICA)

This study evaluated the application of carboxylated multi-walled carbon nanotubes (MWCNTs) as a label in immunochromatographic assay for morphine detection. MWCNTs were carboxylated using nitric acid and characterized by Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, field emission scanning microscopy (FESEM), and dynamic light scattering (DLS). The optimum concentration of polyvinyl pyrrolidone (PVP) as a surfactant for homogenous dispersion of MWCNTs was determined by ultraviolet-visible spectroscopy to be 0.5 mg/mL. The zeta potential of MWCNTs before adding PVP was −41.9 ± 1.02 mV, and after adding PVP, −54.1 ± 0.25 mV. On the surface of MWCNTs, the anti-morphine antibody (AM antibody) had a binding effectiveness ranging from 91.1% to 95.5%. The AM antibody-MWCNTs were conjugated to create immunochromatographic test strips. The visual limit of detection (vLOD) was 1.0 ng/mL and the cutoff concentration (COC) was 10.0 ng/mL. Compared to previous study, carboxylated-MWCNTs as a one-dimensional nanomaterial improved the sensitivity of immunochromatographic assay strips and may be utilized to develop the sensitive immunochromatographic assays.

Ultrathin needle-like NiMoO4/MoO3 heterostructure for supercapacitor and overall water splitting applications

In this study, the morphology of NiMoO4/MoO3 heterostructure was adjusted by adding various amounts of polyvinylpyrrolidone (PVP) as soft-template agent during in-situ solvothermal growth on nickel foam. The electrochemical and physiochemical properties of the free-binder electrode were studied as a function of PVP contents. By adding a proper amount of PVP, the morphology of NiMoO4/MoO3 nanocomposites changed from the agglomerated spherical nanoparticles to the flower-like morphology with the well-distributed nanoneedle-like building blocks. The flower-like NiMoO4/MoO3 heterostructures showed the highest specific capacitance of 3626 Fg−1 at 1 A g−1 and a rate-capability of 76 % by the increase of current density from 1 to 5 A g−1. In alkaline water splitting application, the flower-like microstructure showed the excellent electrocatalytic activity including the low overpotentials of 169 and 318 mV for hydrogen and oxygen evolution reactions, respectively.

Chitosan-PVA-PVP/nano-clay composite: a promising tool for controlled drug delivery.

In this study, chitosan, polyvinyl alcohol (PVA), and polyvinyl pyrrolidone (PVP) were used to create ternary blends reinforced with organically modified montmorillonite nanoclay. Tramadol was used as a model drug to assess the efficacy of these ternary blends as drug delivery systems. The current work demonstrated the highly controlled release of tramadol via transdermal administration. The results of the FTIR investigation revealed the compatibility of the blending components. Among non-drug-loaded formulations, MC6 is the most stable with a 17.6% weight residue at 505 °C and MC11 is the most stable of all the drug-loaded and non-drug-loaded formulations with a weight residue of 22.0% at 505 °C. The XRD studies of the prepared formulations showed crystalline behavior. However, the SEM analysis revealed that no gaps or mixing components were uniformly dispersed in the nanocomposites. Pharmaceutical tests, such as swelling, dissolution, and permeation rates, revealed a strong influence of the PVA concentration. There was a uniform distribution of drug throughout the films with maximum encapsulation efficiency found for MC7 (96.09 ± 0.31) and minimum encapsulation efficiency for MC11 (90.56 ± 0.34)%. Compared to the sodium acetate (pH 4.5) and potassium phosphate buffers (pH 6.8) the swelling and erosion were higher in hydrochloric acid buffer (pH 1.2). An increase in PVA concentration (or decrease in PVP concentration) increases the swelling, dissolution, and permeation rates. In addition, erosion increased with increasing PVP concentration. Furthermore, the nanoclay-reinforced composite showed high permeation. Based on the obtained results, it can be concluded that the produced nanocomposite could be used as an efficient transdermal drug delivery system.

Solubility Enhancement of Poorly Water-Soluble Drug Ritonavir using Polyvinylpyrrolidone and Chitosan-based Platform Technique

The antiviral medication ritonavir (RTV) belongs to the biopharmaceutics classification system (BCS) class II drug category and is known for its high permeability and poor solubility. Therefore, the prime objective of this research was to increase the rate of dissolution and improve the solubility of RTV using a polymer system. Solid dispersions consisting of binary polymer components i.e., chitosan (CH) and polyvinylpyrrolidone (PVP) were prepared using microwave microwave-assisted physical mixing technique and optimization of solid dispersion was performed with 32 factorial designs. Dispersions were analyzed for their physicochemical characteristics by the use of X-ray diffraction (XRD), differential scanning calorimetry (DSC), and fourier transform infrared spectroscopy (FTIR). The polymeric dispersions prepared were evaluated for the release of RTV throughout 1 h in 0.1N sodium chloride in a USP class II dissolving device. The phase solubility study demonstrated a considerable improvement in the saturation solubility of RTV when CH and PVP K30 were present either individually or in combination. Virtual interaction studies between the drug and polymers revealed physical interactions driven by van der Waals and hydrophobic forces between RTV and excipients. Carbonyl, amine, and hydroxyl groups, among others, were probably present in both RTV and CH, which allowed for these interactions to take place. There was no discernible interaction between the RTV and the polymers included in the FTIR research. The dispersion strategies have improved the dissolving rate, according to the in-vitro drug release investigation. A formulation including a polymeric dispersion of the optimal concentration of PVP and chitosan may efficiently boost the release of RTV, according to the in-vitro release profile.

Technical note: hydrogel-based mimics of prostate cancer with matched relaxation, diffusion and kurtosis for validating multi-parametric MRI.

Protocol standardization and optimization for clinical translation of emerging quantitative multiparametric (mp)MRI biomarkers of high-risk prostate cancer requires imaging references that mimic realistic tissue value combinations for bias assessment in derived relaxation and diffusion parameters. This work aimed to develop a novel class of hydrogel-based synthetic materials with simultaneously controlled quantitative relaxation, diffusion, and kurtosis parameters that mimic in vivo prostate value combinations in the same spatial compartment and allow stable assemblies of adjacent structures. A set of materials with tunable T2, diffusion, and kurtosis were assembled to create quantitative biomimetic (mp)MRI references. T2 was controlled with variable agarose concentration, monoexponential diffusion by polyvinylpyrrolidone (PVP), and kurtosis by addition of lamellar vesicles. The materials were mechanically stabilized by UV cross-linked polyacrylamide gels (PAG) to allow biomimetic morphologies. The reference T2 were measured on a 3T scanner using multi-echo CPMG, and diffusion kurtosis-with multi-b DWI. Agarose concentration controls T2 values which are nominally independent of PVP or vesicle concentration. For agarose PVP hydrogels, monoexponential diffusion values are a function of PVP concentration and independent of agarose concentration. Compared to free vesicles, for agarose-PAG combined with vesicles, diffusion was predominantly controlled by vesicles and PAG, while kurtosis was affected by agarose and vesicle concentration. Both hydrogel classes achieved image voxel parameter values (T2, Da, Ka) for relaxation (T2: 65-255ms), apparent diffusion (Da: 0.8-1.7μm2/ms), and kurtosis (Ka: 0.5-1.25) within the target literature ranges for normal prostate zones and cancer lesions. Relaxation and diffusion parameters remained stable for over 6months for layered material assemblies. A stable biomimetic mpMR reference based on hydrogels has been developed with a range of multi-compartment diffusion and relaxation parameter combinations observed in cancerous and healthy prostate tissue.