Polyvinylpyrrolidone Research Articles

DEVELOPMENT AND OPTIMIZATION OF A DOLUTEGRAVIR NANOSUSPENSION USING BOX BEHNKEN DESIGN

Objective: This study aimed to develop and optimize a nanosuspension of Dolutegravir, an integrase inhibitor with low aqueous solubility, using the sonoprecipitation technique. The objective was to enhance the drug's solubility and oral bioavailability by preparing nanosuspension. Methods: A box-behnken design was employed to systematically investigate the impact of stabilizer concentration, sonication amplitude, and time on the particle size and polydispersibility of the nanosuspension formulations. Various stabilizers, including Soluplus®, Poloxamer 188, Poly Vinyl Pyrrolidone (PVP) K90, Hydroxy Propyl Methyl Cellulose (HPMC), and Tween 80, were evaluated. Fourier transform infrared spectroscopy confirmed drug-polymer interactions, while differential scanning calorimetry and X-ray diffraction revealed partial amorphization. Scanning electron microscopy confirmed nanoscale particle size and morphology. Results: The optimized formulation (NS6) with 1% Soluplus®, 65 W amplitude, and 10 min sonication exhibited nanoparticles of 75.3 nm with low polydispersity. NS6 demonstrated enhanced drug release compared to the pure drug, attributed to particle size reduction and amorphization. In vitro tests indicated acceptable stability over time and temperature. Conclusion: The application of Box-Behnken design resulted in an optimized nanosuspension formulation capable of improving the oral bioavailability of poorly soluble Dolutegravir. The formulation exhibited favorable characteristics, including reduced particle size, amorphization, and enhanced drug release, highlighting its potential as an effective delivery system for Dolutegravir in Human Immuno Deficiency Virus (HIV) treatment.

Implications of Low-concentration Polymer on the Physical Stability of Glassy Griseofulvin: Role of the Segmental Mobility.

Crystallization of amorphous pharmaceutical solids are widely reported to be affected by the addition of polymer, while the underlying mechanism require deep study. Herein, crystal growth behaviors of glassy griseofulvin (GSF) doped with various 1% w/w polymer were systematically studied. From the molecular structure, GSF cannot form the hydrogen bonding interactions with the selected polymer poly(vinyl acetate), polyvinyl pyrrolidone (PVP), 60:40 vinyl pyrrolidone-vinyl acetate copolymer (PVP/VA 64), and poly(ethylene oxide) (PEO). 1% w/w polymer exhibited weak or no detectable effects on the glass transition temperature (Tg) of GSF. However, crystal growth rates of GSF was altered from 4.27-fold increase to 2.57-fold decrease at 8 ℃ below Tg of GSF. Interestingly, the ability to accelerate and inhibit the growth rates of GSF crystals correlated well with Tg of polymer, indicating the controlling role of segmental mobility of polymer. Moreover, ring-banded growth of GSF was observed in the polymer-doped systems. Normal compact bulk and ring-banded crystals of GSF were both characterized as the thermodynamically stable form I. More importantly, formation of ring-banded crystals of GSF can significantly weaken the inhibitory effects of polymer on the crystallization of glassy GSF.

DEVELOPMENT, OPTIMIZATION AND IN VITRO CHARACTERIZATION OF HALOPERIDOL NANOCRYSTALS USING 32 FACTORIAL DESIGN

Objective: The main aim of the present study was to improve the dissolution rate of Haloperidol nanocrystals and thereby increase their bioavailability. Haloperidol is a typical antipsychotic drug and it is used to treat schizophrenia as well as acute mania and mixed states associated with bipolar disorder. Haloperidol falls into the Biopharmaceutics Classification System (BCS-II) class of drugs (poorly soluble aqueous and highly permeable) and has poor bioavailability. Methods: The present study involves the preparation and optimization of Haloperidol nanocrystals by the anti-solvent precipitation method using Polaxomer407 and polyvinyl pyrrolidone K30 (PVP K30). The prepared nanocrystals were evaluated for various parameters like particle size, zeta potential, % drug content, % yield, surface morphology, drug-excipient compatibility studies (Fourier-transform infrared spectroscopy (FT-IR) and Differential Scanning Calorimetry (DSC)), and in vitro dissolution studies. Results: Nine preparations were done and the best preparation amongst them was selected for further studies. F7 preparation containingpolaxomer407 and PVP K30 was selected as optimized preparation based on their evaluation parameters. 32 factorial design was used in the preparation. The particle size of the F7 nanocrystals was 300.2±2.7 nm and the zeta potential-36.3±3.2 mV. The % yield was in the range of 63.62±0.3%-98.21±0.8 %. The drug content of various preparations was found to be in the range of 58.46±0.8%-93.54±0.5 %. In vitro dissolution studies showed the highest % drug release for F7(91.54±0.03%) in 10 h. Conclusion: F7 preparation was found to be having acceptable characteristics and thus selected as optimized preparation.

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.

Superior antibacterial performance of surfactant-assisted ZnO nanoflakes produced via Co-precipitation method

Microbiological infections are one of the major problems that modern people encounter. Zinc oxide (ZnO) nanoflakes are excellent antimicrobial agents. The objective of this work was to synthesize ZnO nanoflakes with the assistance of surfactants and investigate the processes behind their antibacterial properties. The experiment involved the synthesis of ZnO using several surfactants, including cetyl trimethyl ammonium bromide (CTAB), polyvinyl pyrrolidone (PVP), and polyethylene glycol (PEG), and its analysis using XRD, FT-IR, SEM, EDAX, and BET methods. Both Gram-positive and Gram-negative bacterial strains were used in these investigations. ZnO nanoflakes aided by CTAB (R-2) had the most promising action against the tested bacterial strains like Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Bacillus cereus. These ZnO nanoflakes with CTAB assistance consistently had greater inhibitory zones than other samples. The R-2 sample’s enhanced surface area and particle size, which result in improved antibacterial activity. The investigation’s outcomes show that the produced nanoflakes have the potential to be useful in antibacterial and other medicinal applications.

Incorporation of efavirenz inclusion complex In Dissolvable Microneedle for enhanced effectiveness of intravaginal drug delivery: A proof of concept study

Efavirenz (EFV) is one of the first line treatments of HIV infection. EFV is one of non-nucleoside reverse transcriptase inhibitors (NNRTIs) that can inhibit the responsible of reverse transcriptase enzyme for HIV replication. In oral administration, EFV exhibits low bioavailability (30–56 %) problem owing to its poor solubility (0.9 μg/mL). In this research, the poor solubility was overcome by formulating EFV as a complex inclusion (IC)with β-cyclodextrin (β-CD). Furthermore, considering the benefits of vaginal delivery, IC was further incorporated into dissolving microneedle systems (DMN) using polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) as biocompatible and biodegradable polymes. The results showed that EFV successfully formed IC by the change of the molecular shape with β-CD polymer, confirmed by FTIR and XRD. Importantly, the results showed that the formulation did not cause lysis and irritation on erythrocytes and blood vessels, showing the safety of this approach. Following its incorporation into DMN, IC-DMN could permeate the skin ex vivo as 78.70 ± 14.22 μg/cm3, which was about 3-times higher compared to DMN containing pure EFV and patch control. The in vivo pharmacokinetic study showed that the maximum plasma concentration of IC-DMN was 13.74 ± 2.48 μg/cm3, EFV-oral 6.27 ± 1,13 μg/cm3, vaginal gel 14.83 ± 3.65 μg/cm3. AUC values for each treatment was 147.33 ± 26.62 h μg/mL, 22.33 ± 4.03 h μg/mL, 63.33 ± 11.44 h μg/mL, respectively, indicating that the purpose of this study which was to increase the bioavailability of EFV was succefully achieved. Therefore, this combibation approach could be new alternative to HIV treatment using EFV in woman.

Design, synthesis, and characterization of stable copper nanofluid with enhanced thermal conductivity

Nanofluids, which are liquids that contain small particles with dimensions in the nanometer range, have gained significant attention in recent years due to their enhanced thermal properties in various applications such as thermal management and energy conversion. This article aims to provide insights into the design and optimization of copper nanofluid synthesis and it investigates the thermal and rheological properties at varying concentrations of nanoparticles and temperature. The method involves simultaneous use of fructose as reducing agent and polyvinyl pyrrolidone as stabilizing agent to enable synthesis of copper nanofluid from copper sulphate. The resulting Newtonian nanofluid had a stability of 3 months with enhanced thermal conductivity of up to ∼500 % compared to 1:1 mixture of water and ethylene glycol which served as the base fluid. The approach is suitable for producing large volume of nanofluid using cost effective materials.

MOF-derived porous carbon microspheres Ni@C-acid as solid-phase microextraction coating for extraction of polycyclic aromatic hydrocarbons from tea infusions

The improvement of the stability and adsorption properties of materials on targets in sample pre-treatment has long been an objective. Extensive efforts have been made to achieve this goal. In this work, metal-organic framework Ni-MOF precursors were first synthesized by solvothermal method using polyvinylpyrrolidone (PVP) as an ideal templating agent, stabiliser and nanoparticle dispersant. After carbonization and acid washing, the nanoporous carbon microspheres material (Ni@C-acid) was obtained. Compared with the material without acid treatment (Ni@C), the specific surface area, pore volume, adsorption performance of Ni@C-acid were increased. Thanks to its excellent characteristics (high stability, abundant benzene rings), Ni@C-acid was used as fiber coatings in headspace solid-phase microextraction (HS-SPME) technology for extraction and preconcentration of polycyclic aromatic hydrocarbons (PAHs) prior to gas chromatography-flame ionization detector (GC-FID) analysis. The experimental parameters of extraction temperature, extraction time, agitation speed, desorption temperature, desorption time and sodium chloride (NaCl) concentration were studied. Under optimal experimental conditions, the wide linear range (0.01-30 ng mL−1), the good correlation coefficient (0.9916-0.9984), the low detection limit (0.003-0.011 ng mL−1), and the high enrichment factor (5273-13793) were obtained. The established method was successfully used for the detection of trace PAHs in actual tea infusions samples and satisfied recoveries ranging from 80.94-118.62 % were achieved. The present work provides a simple method for the preparation of highly stable and adsorbable porous carbon microsphere materials with potential applications in the extraction of environmental pollutants.

Breaking hydrogen bond in metal free carbon nitride to induce peroxymonosulfate nonradical activation: Surface-mediated electron transfer

Breaking hydrogen bond in metal free carbon nitride (CN) to increase peroxymonosulfate (PMS) adsorption for surface-mediated electron transfer has been challenging. Herein, we incorporated N−CN monomer into CN to break hydrogen bond by the introduction of polyvinylpyrrolidone (PVP). The developed nonradical oxidation system achieved selective decomposition of highly hydrophilic contaminants and efficient removal of chemical oxygen demand (58.0%), total phosphorus (88.1%), ammonia nitrogen (100.0%) and total nitrogen (67.8%) from the secondary effluent in a continuous flow reactor. This was attributed to that the breakage of hydrogen bond accelerated the redistribution of electron densities at C and N sites, leading to an increase in the adsorption energy of N site to PMS. This promoted the formation of PVP/CN-PMS* complex for the selective and efficient removal of organics and inorganics. This work provided a new perspective for the selective and long-term treatment of practical wastewater.

3D printing of multi-unit gastro-retentive tablets for the pulsatile release of artesunate

Pulsatile drug delivery is hardly achieved by conventional gastro-retentive dosage forms. Artesunate as a typical anti-malaria medicine needs oral pulsatile release. Here, artesunate-loaded pulsatile-release multi-unit gastro-retentive tablets (APGTs) were prepared with a semi-solid extrusion three-dimensional (3D) printing method. An APGT was composed of three units: artesunate-loaded immediate and delayed release units and a block unit. The matrix of the immediate/delayed release units consisted of polyvinylpyrrolidone (PVP) K30 and croscarmellose sodium, which improved the rapid release of artesunate when contacting water. The block unit consisted of octadecanol, hydroxypropyl methyl cellulose K15M, PVP K30, and poloxamer F68. APGTs showed multi-phase release in simulated gastric liquids (SGLs). The first immediate release phase continued for 1 h followed by a long block phase for 7 h. The second rapid release phase was initiated when the eroded holes in the block unit extended to the inner delayed release unit, and this phase continued for about 14 h. Low-density APGTs could ensure their long-term floating in the stomach. Oral APGTs remained in the rabbit stomach for about 20 h. 3D printing provides a new strategy for the preparation of oral pulsatile-release tablets.

Integrated Janus nanofibers enabled by a co-shell solvent for enhancing icariin delivery efficiency

During the past several decades, nanostructures have played their increasing influences on the developments of novel nano drug delivery systems, among which, double-chamber Janus nanostructure is a popular one. In this study, a new tri-channel spinneret was developed, in which two parallel metal capillaries were nested into another metal capillary in a core–shell manner. A tri-fluid electrospinning was conducted with a solvent mixture as the shell working fluid for ensuring the formation of an integrated Janus nanostructure. The scanning electronic microscopic results demonstrated that the resultant nanofibers had a linear morphology and two distinct compartments within them, as indicated by the image of a cross-section. Fourier Transformation Infra-Red spectra and X-Ray Diffraction patterns verified that the loaded poorly water-soluble drug, i.e. icariin, presented in the Janus medicated nanofibers in an amorphous state, which should be attributed to the favorable secondary interactions between icariin and the two soluble polymeric matrices, i.e. hydroxypropyl methyl cellulose (HPMC) and polyvinylpyrrolidone (PVP). The in vitro dissolution tests revealed that icariin, when encapsulated within the Janus nanofibers, exhibited complete release within a duration of 5 min, which was over 11 times faster compared to the raw drug particles. Furthermore, the ex vivo permeation tests demonstrated that the permeation rate of icariin was 16.2 times higher than that of the drug powders. This improvement was attributed to both the rapid dissolution of the drug and the pre-release of the trans-membrane enhancer sodium lauryl sulfate from the PVP side of the nanofibers. Mechanisms for microformation, drug release, and permeation were proposed. Based on the methodologies outlined in this study, numerous novel Janus nanostructure-based nano drug delivery systems can be developed for poorly water-soluble drugs in the future.

Potensi Pewarna Alami untuk Pengembangan Kemajuan Teknologi Sel Surya Organik

Electrospinning is a modified technology to produce nano-sized fibers which can be used in making thin layers of semiconductor dye sensitized solar cells. Flourate – doped tin oxide (FTO) substrate was placed as a target for deposition of TiO2 nanofiber synthesized from TiO2 solution. The deposition process of a thin layer of TiO2 nanofiber was carried out for 15 minutes. The TiO2 solution synthesized is a mixture of acetic acid, ethanol, polyvinylpyrrolidone (PVP), and titanium tetra – isopropoxide (TTIP). Mixing the synthesis solution was carried out for 24 hours, to obtain a homogeneous TiO2 synthesis solution. The TiO2 nanofiber thin layer deposition process was applied under an electrospinning voltage of 25 kV, the distance of the FTO substrate as the collector layer to the solution syringe was 25 cm to avoid too large solution droplets. Before the deposition stage, the surface of the FTO substrate is first formed using the etching method by coating Zn and removing the conductive layer using HCl, so that a customized conductive layer is obtained. The annealing process of the deposited TiO2 nanofiber layer was carried out for 3 hours at a temperature of 450°C. The spin coating method was carried out to deposit a layer of Poly [2- methoxy- 5- (2- ethyl hexyloxy)- 1,4- phenylene venylene] (MEH-PPV). Coating variations are carried out with 4 different layer thicknesses. MEH – PPV was prepared by mixing chlorobenzene and stirring for 18 hours. Testing and characterization was carried out using current and voltage characterization (I – V meter), as well as image characterization using Scanning Electron Microscopy (SEM) as an analysis of the influence of layers on organic solar cells.

Electrodeposition of Ru on Nanoscale Trench Patterns

Ru deposition in advanced technology nodes can improve performance by providing low resistance in nanoscale features. In this study, we reported the electrochemical reactions of Ru3+ on an Ru surface using multi-cyclic voltammetry (CV) and behavior of additives during Ru electrodeposition using linear sweep voltammetry (LSV) and potentiostatic measurements. Disodium 3,3’-dithiobis(1-propanesulfonate) (SPS), polyvinylpyrrolidone (PVP), and a bromide ion (Br−) were added for bottom-up filling. We investigated the suppression behavior of PVP. The current density and the onset potential of suppressor breakdown were affected by the suppressor concentration. PVP interacted synergistically with Br− and showed additional suppression. PVP formed a suppressing layer with Br− after formation of a bromide layer. SPS could reduce roughness during electrodeposition of Ru. Based on these results, nano-trenches were filled with Ru using the optimized additive condition.

Multimode gradient-index fiber coated with a blend of PEG and PVP as a humidity sensor

A novel humidity sensor based on a multimode graded index unclad fiber optic coated with polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) was proposed. During synthesis process, the fiber diameter underwent optical control resulting in an enhanced repeatability. The achieved sensitivity was found to be 0.219 microwatts per relative humidity percent (µW/%RH), equivalent to 0.212 dB per relative humidity (dB/RH) within a humidity range of 65–95% RH. The response time was 0.02 s per relative humidity percent (s/%RH), indicating rapid detection capabilities. Therefore, this sensor could be used for respiration monitoring. The new sensor has low hysteresis and good repeatability and linearity.

Structural and optical properties of polymer blend nanocomposites based on PVP/PVA incorporated AgNO3

In this study, polymer nanocomposite based on polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), and silver nitrate (AgNO3) has been prepared through chemical reduction rate and casting method for varying concentrations of AgNO3. The PVP/PVA blend consisted of 0.6 wt% PVP and 0.4 wt% PVA. Following that, polymer nanocomposites were prepared by incorporating different concentrations of AgNO3 (0, 10, 20, 30, 40, and 50 wt%) into the polymer blend. The effects of different concentrations of AgNO3 on the structural and optical properties of the PVP/PVA blend were investigated using x-ray diffraction (XRD) and UV–vis absorption spectroscopy. The XRD analysis demonstrated that increasing the concentration of AgNO3 results in a decrease in the degree of crystallinity from 53.73 in the PVP/PVA blend to 15.77 in the PVP/PVA nanocomposite containing 50 wt% AgNO3. UV–vis absorbance spectra were examined to determine optical properties such as the absorption coefficient, absorption edge, optical band gap, and tails of localized states. The results revealed that the increase in AgNO3 concentrations caused a reduction in the absorption edge and optical band gap, alongside an increase in Urbach energy.

Miscibility of Amorphous Solid Dispersions: A Rheological and Solid-State NMR Spectroscopy Study

Miscibility is critical in the prediction of stability against crystallization of amorphous solid dispersions (ASDs) in the solid state. However, currently available approaches for its determination are limited by both theoretical and practical considerations. Recently, a rheological approach guided by the polymer overlap concentration (c*) has been proposed for miscibility quantification of ASDs [J. Pharm. Sci., 112 (2023) 204−212] and shown to be useful in predicting both accelerated and long term physical stability in the absence of moisture. However, this approach can only be performed at high temperatures (slightly above the melting temperature, Tm, of drugs), and little is known about the difference in miscibility between high and low temperatures (e.g., below the glass transition temperature, Tg). Here we compare the miscibility of nifedipine (NIF)/polyvinylpyrrolidone (PVP) ASDs as determined by the rheological approach at 175°C (∼3°C above Tm of NIF) and solid state NMR (ssNMR) 1H T1 and T1ρ relaxation times at -20°C (∼66°C below Tg of NIF). Our results indicate agreement between the two methods. For low molecular weight (Mw) PVP, T1ρ measurements are more consistent with the rheological approach, while T1 measurements are closer for relatively high Mw PVP. Our findings support the use of the c* based rheological approach for inferring miscibility of deeply cooled ASDs.

Targeting TGFβ receptor-mediated snail and twist: WSG, a polysaccharide from Ganoderma lucidum, and it-based dissolvable microneedle patch suppress melanoma cells

Cutaneous melanoma is a lethal skin cancer variant with pronounced aggressiveness and metastatic potential. However, few targeted medications inhibit the progression of melanoma. Ganoderma lucidum, which is a type of mushroom, is widely used as a non-toxic alternative adjunct therapy for cancer patients. This study determines the effect of WSG, which is a water-soluble glucan that is derived from G. lucidum, on melanoma cells. The results show that WSG inhibits cell viability and the mobility of melanoma cells. WSG induces changes in the expression of epithelial-to-mesenchymal transition (EMT)-related markers. WSG also downregulates EMT-related transcription factors, Snail and Twist. Signal transduction assays show that WSG reduces the protein levels in transforming growth factor β receptors (TGFβRs) and consequently inhibits the phosphorylation of intracellular signaling molecules, such as FAK, ERK1/2 and Smad2. An In vivo study shows that WSG suppresses melanoma growth in B16F10-bearing mice. To enhance transdermal drug delivery and prevent oxidation, two highly biocompatible compounds, polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP), are used to synthesize a dissolvable microneedle patch that is loaded with WSG (MN-WSG). A functional assay shows that MN-WSG has an effect that is comparable to that of WSG alone. These results show that WSG has significant potential as a therapeutic agent for melanoma treatment. MN-WSG may allow groundbreaking therapeutic approaches and offers a novel method for delivering this potent compound effectively.

Polyvinylpyrrolidone Assisted One-Pot Synthesis of Size-Tunable Cocktail Nanodrug for Multifunctional Combat of Cancer.

The in vivo barriers and multidrug resistance (MDR) are well recognized as great challenges for the fulfillment of antitumor effects of current drugs, which calls for the development of novel therapeutic agents and innovative drug delivery strategies. Nanodrug (ND) combining multiple drugs with distinct modes of action holes the potential to circumvent these challenges, while the introduction of photothermal therapy (PTT) can give further significantly enhanced efficacy in cancer therapy. However, facile preparation of ND which contains dual drugs and photothermal capability with effective cancer treatment ability has rarely been reported. In this study, we selected curcumin (Cur) and doxorubicin (Dox) as two model drugs for the creation of a cocktail ND (Cur-Dox ND). We utilized polyvinylpyrrolidone (PVP) as a stabilizer and regulator to prepare Cur-Dox ND in a straightforward one-pot method. The size of the resulting Cur-Dox ND can be easily adjusted by tuning the charged ratios. It was noted that both loaded drugs in Cur-Dox ND can realize their functions in the same target cell. Especially, the P-glycoprotein inhibition effect of Cur can synergistically cooperate with Dox, leading to enhanced inhibition of 4T1 cancer cells. Furthermore, Cur-Dox ND exhibited pH-responsive dissociation of loaded drugs and a robust photothermal translation capacity to realize multifunctional combat of cancer for photothermal enhanced anticancer performance. We further demonstrated that this effect can also be realized in 3D multicellular model, which possibly attributed to its superior drug penetration as well as photothermal-enhanced cellular uptake and drug release. In summary, Cur-Dox ND might be a promising ND for better cancer therapy.

Fabrication and evaluation of stable amorphous polymer-drug composite particles via a nozzle-free ultrasonic nebulizer

We present a promising method for producing amorphous drug particles using a nozzle-free ultrasonic nebulizer with polymers, specifically polyvinylpyrrolidone (PVP), poly(acrylic acid) (PAA), and Eudragit® S 100 (EUD). Model crystalline phase drugs–Empagliflozin, Furosemide, and Ilaprazole–are selected. This technique efficiently produces spherical polymer-drug composite particles and demonstrates enhanced stability against humidity and thermal conditions, compared to the drug-only amorphous particles. The composite particles exhibit improved water dissolution compared to the original crystalline drugs, indicating potential bioavailability enhancements. While there are challenges, including the need for continuous water supply for ultrasonic component cooling, dependency on the solubility of polymers and drugs in volatile organic solvents, and mildly elevated temperatures for solvent evaporation, our method offers significant advantages over traditional approaches. It provides a straightforward, flexible process adaptable to various drug-polymer combinations and consistently yields spherical amorphous solid dispersion (ASD) particles with a narrow size distribution. These attributes make our method a valuable advancement in pharmaceutical drug formulation and delivery.

Effect of polyvinylpyrrolidone and lithium chloride composite desiccant-coated heat exchangers on dehumidification studies

Cooling systems are necessities that remain energy intensive, particularly in tropical regions with elevated humidities and temperatures. Conventional vapor-compression air-conditioners are often inefficient because the sensible and latent heat loads are intrinsically coupled. To realize more energy-efficient cooling, solid desiccant-coated devices can be introduced to mitigate the latent heat load. Among such devices, desiccant-coated heat exchangers (DCHEs) are attractive for enabling nearly isothermal dehumidification. Hence, desiccants with high sorption capacity and rapid kinetics are essential. Solid polymeric desiccants are well-positioned to meet these requirements but comprehensive studies on the dehumidification performance of solid polymeric desiccant-coated heat exchangers are currently lacking. In this study, we investigated the potential of polyvinylpyrrolidone (PVP) and lithium chloride (LiCl) composites as desiccant materials at both material and system levels in terms of gravimetric water uptake. Specifically, LiCl is a hygroscopic salt bound by the moisture-sorbing PVP matrix. This work also demonstrates how the Elovich model accurately predicted the PVP-LiCl composite’s sorption kinetics. The results show that the optimum PVP-LiCl composite ratio is 66.7 wt%, with an equilibrium sorption capacity of 280 % at 75 % RH and 25 °C, compared to 29 % for silica gel under the same condition. With much superior sorption kinetics and capacity, the PVP-LiCl-coated prototype heat exchanger demonstrated a moisture removal capacity eight times higher than a silica gel-coated one under dynamic flow towards energy savings in air-conditioning systems.