Search Results (1,023)

Improving the dissolution and solubility of poorly water-soluble drugs remains a major challenge in drug development. Solid dispersion (SD) techniques offer an effective strategy by which to enhance the bioavailability of BCS Class II drugs such as ivermectin (IVM). This study aimed to develop and validate stability-indicating analytical methods for the quantification of IVM and to evaluate the performance of the formulated SDs. A novel RP-HPLC and a UV spectrophotometric method were developed and validated in accordance with ICH guidelines. IVM SDs were prepared via physical mixing (PM), solvent evaporation (SE), and melt fusion (MF) using Poloxamer 188, Kollicoat^® IR, and PEG 6000 at respective ratios of 1:1, 1:3, and 1:5. Dissolution studies showed a marked enhancement in drug release from SDs prepared by SE and MF methods compared with pure IVM. Among all formulations, the Poloxamer 188-based binary SD prepared by the SE method at a 1:5 ratio exhibited the highest dissolution (98.55% at 60 min), with release kinetics following anomalous (non-Fickian) transport (n = 0.681) according to the Korsmeyer–Peppas model. Solid-state characterization evidenced by FTIR, DSC, TGA, and SEM confirmed the transformation of IVM from its crystalline form to an amorphous state. Future studies will focus on the in vivo evaluation of the optimized IVM SD formulations. Full article

Controlling the microstructure of electroless nickel coatings is crucial for optimizing the interfacial properties of carbon fibers. However, a systematic understanding of how dispersants can effectively leverage the refining effect of nanoparticles in composite plating systems remains lacking. This paper proposes the use of a composite dispersant, comprising polyethylene glycol (PEG) and sodium methylene bis-naphthalene sulfonate (NNO) at a 1:1 mass ratio, for nano-Al₂O₃ to achieve microstructure refinement of nickel coatings on carbon fiber surfaces. The results demonstrate that the composite dispersant modifies the surface state and dispersion stability of Al₂O₃ particles through synergistic adsorption, thereby regulating the nucleation and growth behavior of the Ni-P alloy. At an optimal composite dispersant concentration of 3 g/L, the coating exhibits the most compact structure, with Ni-P particle size refined to approximately 181 nm. The coating consists of two phases: crystalline Ni₃P and amorphous Ni-P. The dual adsorption effect of the dispersant—inhibiting Al₂O₃ agglomeration while improving the surface wettability of carbon fibers—is key to enhancing the refinement efficiency. Conversely, excessive dispersant addition leads to deteriorated coating quality. This study provides experimental evidence for understanding the multiphase interfacial interaction mechanism involving organic additives, nanoparticles, and metal deposition, and offers a novel strategy for controlling the surface functionalization of carbon fibers. Full article

Background/Objectives: Cannabidiol (CBD) has emerged as a potential therapeutic agent for respiratory disorders, including asthma and chronic obstructive pulmonary disease. However, its clinical translation via pulmonary delivery is limited by poor aqueous solubility, chemical instability, and low local bioavailability. This study aimed to develop and optimize a sodium stearate (NaSt)-based spray-dried dry powder inhaler (DPI) formulation to enhance the aerosol performance, dissolution, and storage stability of CBD. Methods: CBD microparticles were prepared by spray drying using NaSt as the primary excipient. The feed preparation method, spray-drying parameters, and CBD:NaSt ratios were systematically optimized. The resulting powders were evaluated for aerodynamic properties using cascade impaction, dissolution behavior in simulated lung fluid, solid-state characteristics, and accelerated stability under stress conditions. Results: The optimized formulation, SD-4, a spray-dried CBD:NaSt formulation prepared at a 20:80 weight ratio using Process B, demonstrated excellent aerosolization performance, with a fine particle fraction (FPF) exceeding 50% and a mass median aerodynamic diameter (MMAD) of 5.08 ± 0.1 μm. Dissolution testing revealed more than a three-fold increase in drug release compared with raw CBD, attributed to amorphous dispersion within the NaSt matrix and surfactant-induced micellization. Accelerated stability studies confirmed improved retention of the amorphous state and drug content, while antioxidant incorporation further reduced oxidative degradation. Conclusions: The NaSt-based spray-dried formulation significantly improved aerosol deposition efficiency, dissolution rate, and physicochemical stability of CBD. This formulation strategy may provide a promising platform for pulmonary delivery of poorly water-soluble compounds. Full article

Soft magnetic composite materials have a low total loss and high magnetic conductivity and are highly desirable for high-frequency motors, semiconductors, and 5G communication technologies. However, these composites often contain a high-volume fraction of soft magnetic metallic powders and are difficult to process into complex shapes. Herein, iron-based amorphous powders were surface-modified with silane coupling agents (DTMS and KH570) and applied in 3D direct ink writing (DIW). The modified powders exhibit improved compatibility and dispersion in epoxy resin. The optimized 92.3 wt% FeSiB@3.35 wt% KH570/EP slurry shows favorable rheological properties and a dense interfacial microstructure. The printed composite achieves the best magnetic performance (M_s: 137.02 ± 1.2 emu/g, H_c: 6.63 ± 0.2 Oe) and stable permeability up to 1 GHz. The surface modification enhanced slurry fluidity, preventing nozzle blockage and increasing powder loading. Various shaped magnetic cores were successfully fabricated with excellent magnetic properties and printing quality. Our work paves a new way for realizing the high processibility of soft magnetic composites, which lays a foundation for a technique for the wide applications of these materials in various electronic devices. Full article

Background: Amorphous drug formulations are commonly used to improve the solubility and bioavailability of poorly soluble molecular pharmaceuticals, yet less is known about their molecular conformations and local bonding interactions than their crystalline phases. Methods: High-energy X-ray diffraction structure factor measurements have been made on liquid and glassy nifedipine (NIF), felodipine (FEL), NIF 1:3 polyvinylpyrrolidone (PVP), and FEL 1:3 PVP wt.% mixtures. The corresponding X-ray pair distribution functions have been interpreted using empirical potential structure refinement using different models and density functional theory conformer calculations. Results: In both NIF and FEL, the NH···O inter-molecular hydrogen bonds between the pyridyl nitrogen and ester carbonyls are found to be considerably weaker than those observed in the crystalline polymorphs. For nifedipine, it is proposed that either inter-molecular NH…ON nitro bonds are present and/or a fraction (<20%) of conformational changes, with the aryl ring flipped, occur in the liquid state. For felodipine, the models indicate significant disorder associated with the methyl and ethyl side chains in the liquid state, with the main peak intensity at 3.0 Å arising from intra-molecular Cl-Cl atom pairs. When nifedipine molecules are incorporated into PVP, our models show they possess stronger NH···O bonds to the PVP polymer than felodipine molecules, which have stronger affinity for bonding to the polymer than to other felodipine molecules. Conclusions: The amorphous forms of both NIF and FEL show much weaker hydrogen bonding than found in their crystalline phases. Liquid NIF also exhibits configurations which are not observed in the crystal phases. Full article

Selenium nanoparticles (SeNPs) represent promising bioactive agents due to their reduced toxicity and multifunctional biological properties. In this study, SeNPs were synthesized via an eco-friendly phytosynthesis approach using Curcuma longa extract, yielding curcumin-functionalized selenium nanoparticles (cur–SeNPs). The composites (cur–SeNPs), either in native extract form or isolated, were incorporated into siloxane hybrid matrices prepared by the sol–gel method from tetraethyl orthosilicate: dimethyldimethoxysilane precursors, with polyvinylpyrrolidone (PVP) as a structural modifier. The host matrices were differentiated by the ratios between the precursors of the siloxane network, 3:1 for CS0–CS4, respectively, 1:1 for CS5, modified with PVP in the case of CS2 and CS3. These were loaded with cur–SeNPs–T in the cases of CS1, CS2, CS5 or with cur–SeNPs for CS3 and CS4. FTIR, XRD, SEM, and EDX analyses confirmed the formation of amorphous siloxane networks with well-dispersed SeNPs (up to ~12 wt%). PVP incorporation generated ordered mesoporous structures, increasing total pore volume sixfold and enlarging the average pore diameter to 9.26 nm. Studies about selenium ion release demonstrate that mesoporosity significantly enhances diffusion-controlled release. Antimicrobial assays against Staphylococcus aureus, Escherichia coli, and Candida albicans reveal a synergistic effect between curcuminoids and SeNPs, particularly in matrices with higher nanoparticle loading. The sol–gel technique for obtaining hybrid materials is very versatile regarding the supports on which the resulting materials or the compounds hosted in these host networks can be deposited. The dynamics of the development of hybrid materials is also reflected in the multitude of applications in various fields such as bio-medical, electronics, agriculture or food. Results obtained in this work highlight the potential of the developed systems for antimicrobial coatings on glass substrates and targeted delivery applications. Full article

Background/Objectives: Fungal keratitis remains a vision-threatening infection, and current amphotericin B (AmphB) eye drops suffer from low corneal residence time, poor aqueous solubility, and the need for frequent dosing. This study develops electrospun nanofiber-based ophthalmic inserts combining polyvinyl alcohol (PVA), gamma-cyclodextrin (γ-CD), and sodium taurocholate (STC) to enhance AmphB solubility and provide a non-invasive, rapidly dissolving ophthalmic dosage form. Methods: γ-CD and STC-enhanced AmphB-loaded PVA nanofiber-based ophthalmic inserts with varying γ-CD and STC concentrations were prepared by electrospinning and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Drug content, in vitro release (Weibull modeling), antifungal activity against Candida albicans, Fusarium solani, and Aspergillus fumigatus, ocular cytocompatibility using the Hen’s Egg Test on Chorioallantoic Membrane (HET-CAM), and accelerated stability (40 ± 2 °C, 75 ± 5% relative humidity, 4 weeks) were evaluated. Results: Bead-free nanofibers with mean diameters between 216 ± 33 nm and 310 ± 35 nm were obtained, and XRD confirmed complete amorphization of AmphB within the PVA nanofiber matrix, forming an amorphous solid dispersion. All formulations showed rapid and nearly complete AmphB release (≈100% within 60 min), with Weibull β values < 0.75, indicating Fickian diffusion-controlled release. AmphB-loaded PVA nanofiber-based ophthalmic inserts produced inhibition zones and broth susceptibility profiles comparable to AmphB in dimethyl sulfoxide (DMSO), demonstrating preserved antifungal activity. HET-CAM scores (0–0.9) classified the inserts as practically non-irritant, and SEM/FTIR after accelerated storage showed no relevant morphological or physicochemical changes. Conclusions: These γ-CD and STC-enhanced AmphB-loaded PVA nanofiber-based ophthalmic inserts provide a non-invasive, rapidly dissolving ophthalmic dosage form that combines amorphous AmphB, immediate drug availability, and good ocular tolerance, supporting their further development as a patient-friendly treatment option for fungal keratitis. Full article

Polyphenols have attracted considerable scientific interest over recent years due to their broad spectrum of biological activities, including antioxidant, cardioprotective, anti-inflammatory, antidiabetic, and anticancer properties. However, their practical application is often limited by unfavorable physicochemical characteristics, particularly low aqueous solubility. Consequently, amorphous solid dispersions (ASDs) have been extensively investigated as a formulation strategy to overcome these limitations. This article represents the first part of a two-part review and presents the current state of the art in amorphous solid dispersions of polyphenols. The available literature is systematically summarized with respect to the investigated polyphenolic compounds, the employed carriers (with particular emphasis on polymeric systems), the preparation methods, and the solid-state characterization techniques used to confirm amorphization. Both single-component systems and binary combinations of polyphenols reported in the literature are considered. The collected data are presented in tabular form and complemented by a heat map illustrating the frequency of reported polyphenol–carrier combinations. The aim of this review is to organize the available knowledge, identify the most extensively studied systems, and highlight research areas that remain underexplored. A detailed discussion of the pharmaceutical benefits and mechanistic aspects of polyphenols in ASD systems will be provided in Part II. Full article

It is limited to use cellulose nanocrystals (CNCs) as green lubricant nanoadditives due to their high biodegradability. A promising solution is to convert CNCs into biocarbon. Herein, a multi-layer biocarbon (MLC) was prepared by carbonizing CNCs with an ionic liquids–thermal method. MLC was characterized comprehensively and then dispersed into rapeseed oil for use as a nanoadditive. The tribological performance of the MLC nanoadditive was evaluated using a ball-on-disc tribometer. The lubrication mechanism of the MLC nanoadditive was elucidated according to wear analysis of the worn surfaces and wear residues. It was found that MLC had a high carbon content of 77 at% and showed a two-dimensional multi-layered morphology. Each layer was composed of amorphous carbon nanosheets embedded with many crystalline carbon dots. The MLC nanoadditive was of excellent dispersibility and stability in rapeseed oil. Tribological experiments showed that the MLC nanoadditive, with a concentration of merely 0.04 wt%, led to a decrease in the frictional coefficient by 12.4% and the wear volume by 50.7%, having higher efficacy than the CNC nanoadditive. The exceptional lubrication effect of the MLC nanoadditive was mainly attributable to its interfacial deposition behavior and its subsequent fragmenting behavior. This work develops a novel method for biocarbon preparation and showcases its significant potential in lubrication applications. Full article

Recently, more sustainable and biodegradable packaging materials have begun to attract attention in food packaging due to major, rising concerns related to plastic usage. This study aims to develop and characterize biodegradable food packaging materials, namely poly(lactic acid) (PLA) and poly(ε-caprolactone) (PCL) enriched with pomegranate peel extract (PoPE). Firstly, the optimal extract selected was a 24 h maceration of PoPE with 60% ethanol, after production with different solvents and methods. PLA- and PCL-based films were produced via melt compounding with the addition of PoPE at different concentrations (1, 3, 5 and 10%, w/w). FTIR confirmed that the PoPE did not modify the chemical backbones of PLA or PCL, with only a more pronounced O–H band in PCL, suggesting mainly non-covalent/physical interactions. UV–Vis spectroscopy showed tunable warm coloration and strong UV shielding with reduced transparency; for PLA ~3–5 wt.%, PoPE enabled near-complete UV blocking, while PCL achieved very high UV protection even at low loadings. PoPE improved toughness in PLA (3–5 wt.%) and maintained ductility in PCL (1–10 wt.%). PoPE-added PLA and PCL films maintained thermal stability up to 10 wt.% according to TGA results. DSC/XRD indicated a matrix-dependent crystallization response. PLA remained largely amorphous, whereas PoPE promoted PCL crystallinity without changing polymer crystal polymorphs. SEM images revealed homogenous dispersion of PoPE in the films. Full article

High-speed laser cladding (HLC) technology can provide high cooling rates and low dilution rates for the preparation of metastable Fe-based amorphous phases. In this work, the effects of Ta content on the microstructure, mechanical properties, and soft magnetic performance of Fe-based amorphous alloys were systematically investigated. The results indicated that Ta remained uniformly dispersed within the FeSiB amorphous powder, and no new phases were formed after mechanical ball milling. The higher mixing enthalpy of Ta and its atomic radius difference from other elements (such as Fe, Si, B) were beneficial in improving glass-forming ability (GFA), and with an increase in Ta element content from 0% to 2%, 4% and 6%, the amorphous phase content was 48.6%, 51.5%, 60.4% and 54.8%, respectively. The average microhardness of the coating with a Ta content of 4% was 1310 HV_0.2, which was 50HV_0.2 higher than before; in addition, the wear rate reduced from 2.21 × 10⁻⁴ mg·N⁻¹·m⁻¹ to 2.06 × 10⁻⁴ mg·N⁻¹·m⁻¹. Also, corrosion tests showed that the coating with a Ta content of 4% displayed superior corrosion resistance compared to that before the Ta addition. However, because the element Ta could alter the local electronic environment and enhance the local magnetic anisotropy of FeSiB, the saturation magnetic flux density (Ms) decreased from 1.64 T to 1.56 T, and the coercivity (Hc) increased from 0.9 A/m to 1.3 A/m, which caused degradation of the soft magnetic properties. Full article

Second harmonic (SH) radiation can only be generated in non-centrosymmetric bulk crystals under electric dipole approximation. Nonlinear thin films made from bulk crystals are technologically challenging because of complex and high-temperature fabrication processes. In this work, heterostructures made of two distinct amorphous materials, namely SiO₂ and TiO₂, were prepared through plasma-enhanced atomic layer deposition (PEALD) with deposition temperature of 100 °C. By using the uniaxial dispersion model, we characterized the form birefringence of the deposited films, which can play a crucial role for the phase-matching condition in nonlinear waveguides or other nonlinear optical applications. By applying a fringe-based technique, we determined the largest diagonal component of the effective bulk second-order susceptibility, ${\chi }_{zzz}^{\left(2\right)}$ = 1.30 ± 0.13 pm/V, at a wavelength of 1032 nm. Noteworthy, we observed strong SHG signals from two-component nanolaminates, which are several orders of magnitude larger than those from single layers. The SHG signals from our samples only require the broken inversion symmetry at the interface. Here, optical properties of nanocomposites can be precisely engineered using the promising PEALD technology. Full article

This work explores the influence of two preparation methods, solvent casting and melt mixing, on the structure–property relationships of poly-L-lactic acid (PLLA) composites reinforced with char derived from different waste feedstocks. Three types of char were produced by slow pyrolysis at 550 °C: olive pruning waste biochar (OC), tyre-derived char (TC), and a 1:1 hybrid co-pyrolyzed char (OTC). Each filler was incorporated into PLLA at 1 and 2 wt.% loadings, and the resulting composites were characterized through physicochemical, thermal, mechanical, and electrical analyses. Raman, FTIR, and SEM analyses revealed distinct structural characteristics for each char, with the hybrid OTC exhibiting the highest structural order due to synergistic interactions during co-pyrolysis. The preparation method affected filler dispersion. Solvent-cast films displayed micrometric agglomerates and interfacial voids, whereas melt mixing ensured a more homogeneous distribution. Thermal characterization showed that char addition did not significantly alter the crystallization or melting behavior of PLLA, although melt-mixed samples exhibited restricted chain mobility. Mechanical tests revealed opposing effects of filler loading depending on processing: in solvent-cast materials, stiffness increased while strength remained nearly unaffected, whereas melt-mixed composites exhibited reduced modulus and strength, attributed to the disruption of the denser amorphous structure generated during melt processing. Electrical resistivity depended on the preparation method. Solvent-cast composites remained insulating, while melt mixing, with OTC at 2 wt.%, led to a resistivity drop (down to 0.02 × 10¹⁵ Ω·cm from 20 × 10¹⁵ Ω·cm for unfilled PLLA), although all materials remained within the insulating regime. Overall, this work provides insight into the role of sustainable char fillers in improving the performance of PLLA composites and highlights the interplay between processing method and material properties. The developed PLLA/char composites are promising candidates for applications in flexible electronics, sensors, and antistatic components, as well as in lightweight structural materials and energy devices. Full article

Background/Objectives: Amorphous solid dispersions (ASDs) produced via hot-melt extrusion (HME) and fused deposition modeling (FDM) 3D printing represent a promising strategy for improving the performance of poorly water-soluble drugs. However, the integrated HME-FDM workflow is inherently energy-intensive, and sustainability considerations are rarely incorporated into formulation and process optimization. The present study aimed to develop and optimize indomethacin (IND) ASDs using a systematic Design of Experiment (DoE) framework that integrates electrical energy consumption as a quantitative response alongside pharmaceutical performance attributes. Methods: Polymer–plasticizer miscibility was screened using hot-stage microscopy, followed by filament preparation via HME. A factorial DoE was applied to optimize drug loading and extrusion temperature considering electrical energy consumption, extrusion yield, encapsulation efficiency, and residual crystallinity. Solid-state characterization was performed using DSC and XRD. The optimized filament was subsequently subjected to geometry screening and a second DoE to optimize platform temperature, nozzle temperature, and printing speed with respect to printing time, electrical energy consumption, and drug assay. Results: Complete drug amorphization was achieved within a defined thermal window, with residual crystallinity governed by kinetic dissolution constraints at lower extrusion temperatures. Electrical energy demand during both HME and FDM was strongly influenced by thermal setpoints and process duration. Multi-response overlay analysis identified sustainability-oriented operating windows for both stages. Experimental validation confirmed close agreement between predicted and observed responses, demonstrating simultaneous reduction in electrical demand and maintenance of dose accuracy and solid-state stability. Conclusions: This study demonstrates that electrical energy consumption can be systematically embedded as a quantitative design variable in pharmaceutical process optimization. The proposed dual-stage DoE strategy establishes a rational framework for developing 3D-printed ASD dosage forms that balance molecular performance and environmental efficiency. Full article

Background/Objectives: Hot-melt injection molding (HMIM) was evaluated as a solvent-free process for the preparation of glibenclamide (GLB), a poorly soluble BCS Class II drug, glassy solutions with the objective of improving dissolution and bioavailability for diabetes. Methods: GLB was blended at a concentration of 10% w/w with PVP K25, PVP VA64, and Soluplus^® (SOL) matrices. The miscibility of the GLB–polymer systems (matrices) was calculated based on the Hansen solubility parameters and validated using differential scanning calorimetry (DSC) analysis. The HMIM extrudates were milled into granules and analysed for their solid-state properties (DSC, XRPD, FTIR, and SEM studies), and flow properties. The produced granules were compressed into immediate release tablets and assessed for in vitro performance, stability, and in vivo bioavailability using 20 healthy male Sprague Dawley rats. Results: Findings revealed the formation of single-phase glassy solutions, specifically for PVP VA64 and SOL, which also exhibited advantageous manufacturing and extrudate clarity. The glassy solution formulations showed considerably improved dissolution characteristics compared with the crystalline GLB and the commercial product. The glassy solution formulations displayed fast drug release for PVP K25 and PVP VA64, and biphasic drug release for SOL. Stability testing confirmed the capability of PVP VA64 and SOL to maintain GLB in a molecularly dispersed, amorphous state for 12 months. The in vivo assessment revealed an increase in relative bioavailability to 246.3% and 124.5% for the SOL and PVP VA64 formulations when compared to the commercial formulation. Conclusions: Overall, the findings demonstrate the potential of HMIM-processed glassy solutions, especially those prepared using SOL, as promising platforms for promoting oral delivery of the poorly soluble antidiabetic GLB. Full article