Search Results (106)

Background/Objectives: Enhancing excipient functionality through environmentally friendly and scalable processing methods is essential for improving the manufacturability and performance of orally disintegrating tablets (ODTs). Microwave-assisted wet granulation enables controlled microstructural modification without chemical alteration of excipient components. This study aimed to develop and evaluate a rice starch (RS)–mannitol co-processed excipient using microwave-assisted wet granulation for direct compression of ODTs. Methods: RS and mannitol were co-processed by wet granulation followed by microwave treatment under varying power levels and irradiation times. The effects of processing conditions on granule morphology, solid-state properties, porosity, powder flow, compressibility, wettability, and disintegration behavior were systematically investigated. The optimized excipient was further evaluated in ODT formulations containing chlorpheniramine maleate and piroxicam and benchmarked against a commercial co-processed excipient (Starlac^®). Results: Microwave treatment generated internal vapor pressure that promoted pore formation and particle agglomeration, resulting in enhanced powder flowability (compressibility index 8.4–10.8%). Partial crystallinity reduction and microstructural modification improved compressibility and surface wettability compared with non-microwave-treated materials. The optimized formulation (MW-RM-H-30) exhibited rapid wetting (25 s), high water absorption (90.5%), low contact angle (42°), and fast tablet disintegration (31 s). ODTs prepared with MW-RM-H-30 showed rapid disintegration (42 s for chlorpheniramine maleate and 32 s for piroxicam) and dissolution behavior comparable to Starlac^®. Conclusions: Microwave-assisted wet granulation provides an efficient, scalable, and environmentally friendly strategy for engineering starch-based co-processed excipients with enhanced functionality for direct compression ODT applications. The developed excipient demonstrates strong potential for solid dosage form manufacturing. Full article

Paediatric formulations are pharmaceutical dosage forms specifically designed to meet the physiological, developmental, pharmacokinetic, and practical needs of patients from birth to adolescence. Developing safe, effective, and age-appropriate medicines for children remains a significant challenge due to their age-dependent variability in physiological development, pharmacokinetic profiles, and therapeutic needs. These differences, combined with practical barriers such as poor palatability, limited swallowability, inappropriate dosage form size, and instability, often lead to the modification of adult medicines—practices that can cause dosing inaccuracies, contamination risks, and reduced therapeutic efficacy. Three-dimensional printing has emerged as a promising solution to address these limitations by creating personalised paediatric dosage forms with adjustable strengths, multilayer structures for controlled release, and child-friendly shapes that may improve acceptability and adherence. This review offers an overview of the physiological, technological, and regulatory factors involved in developing 3D-printed paediatric medicines. The Critical Quality and Performance Attributes relevant to this field—including dose accuracy and flexibility, release kinetics, palatability, product dimensions, material choice, safety, stability, cost-effectiveness, production time, scalability, and reproducibility—are discussed in the article. Additionally, the review discusses the evolving Good Manufacturing Practice and regulatory landscape necessary to ensure the quality, safety, and consistency of 3D-printed medicinal products. Overall, these insights underline the transformative potential of 3D printing as a pathway towards safer, more effective, and truly personalised pharmacotherapy for paediatric patients. Full article

This paper focuses on the resource utilization of phosphogypsum, a major industrial by-product from phosphate fertilizer production, in highway engineering materials, exploring its performance optimization and collaborative modification mechanisms. Phosphogypsum, primarily composed of CaSO₄·2H₂O, faces challenges such as acidity (pH ≈ 3.56), poor water resistance, and strength limitations, which hinder its engineering application. This study investigates pretreatment methods (e.g., lime neutralization, physical grinding) and the synergistic effects of additives like metakaolin, steel slag, slag powder, and stone powder. The results show that adjusting phosphogypsum’s pH to 10 via lime neutralization significantly improves its mechanical properties, with its 28-day compressive strength increasing by 21%. The optimal dosage of cement as an alkaline activator is 4%, while steel slag performs best at 10%. Metakaolin (11% dosage) enhances the 28-day strength of 30% phosphogypsum-containing systems by 89–114% through pozzolanic reactions, forming a high-strength aluminosilicate network, enabling the preparation of C35 concrete with a 28-day strength of 44.5 MPa. Additionally, stone powder exhibits the most effective strength improvement, with the 56-day strength increasing by 12.5 MPa compared with the reference group. Economically, utilizing 30% phosphogypsum and 11% metakaolin reduces C35 concrete costs by 15–20%. This research provides theoretical and technical support for the large-scale application of phosphogypsum in highway engineering, addressing environmental and economic challenges. Full article

This study systematically investigates the synergistic modification effects of two high-modulus additives on SBS-modified asphalt through microstructural characterization and performance evaluation. Fluorescence microscopic analysis reveals that the additive particles undergo swelling over time and form an interconnected network structure via phase separation dynamics. Rheological tests demonstrate a significant enhancement in high-temperature performance: at the optimal dosage of 10 wt%, the complex modulus increases by approximately 215%, and the rutting factor improves by about 300% compared to the control group. The results from multiple stress creep recovery (MSCR) tests confirm the material’s superior elastic recovery capability and reduced non-recoverable creep compliance. However, the incorporation of the additives adversely affects low-temperature ductility. The penetration of (two distinct high-modulus agents, designated as HMA-A and HMA-B) HMA-B decreases by approximately 36.8% more than that of HMA-A, accompanied by significantly lower low-temperature toughness. A dosage of 10% is identified as the critical threshold, which maximizes rutting resistance while minimizing low-temperature performance degradation. Based on these findings, this paper proposes an integrated design paradigm of “microstructure–performance–dosage,” recommending HMA-B for high-stress pavement channels and HMA-A for regions with substantial temperature variations. Full article

Polyurethane (PU), owing to its superior physicochemical properties, is considered an ideal modifier for asphalt. To improve the mechanical performance and service durability of asphalt pavements, PU-modified asphalts with varying dosages were prepared and evaluated through laboratory experiments and molecular dynamics simulations. Rheological, thermodynamic, and mechanical tests, as well as asphalt–aggregate adhesion energy calculations, were conducted to elucidate the modification mechanism, aging resistance, and interfacial behavior. The results showed that PU incorporation significantly enhanced rutting resistance at high temperatures, flexibility at low temperatures, and overall load-bearing capacity. Under ultraviolet and long-term aging, PU-modified asphalts exhibited notably lower performance degradation than base asphalt. At the molecular level, PU absorbed light fractions and formed a cross-linked network, reducing the free volume fraction and strengthening resistance to deformation. Moreover, PU substantially improved asphalt–aggregate adhesion energy, thereby reinforcing interfacial bonding. These findings provide theoretical insights and practical guidance for the optimal design and engineering application of PU-modified asphalt. Full article

Asiatic acid is an ursane-type pentacyclic triterpenoid compound extracted from the Umbelliferae plant Centella asiatica. Studies have shown that asiatic acid exhibits a wide range of pharmacological activities, including anti-tumor, anti-inflammatory, hypoglycemic, antimicrobial, neuroprotective, and wound healing effects. Asiatic acid is currently used in clinical settings in the form of tablets, capsules, and ointments, primarily for treating inflammation as well as burns, keloids, and other skin disorders. However, its poor water solubility, rapid metabolism, and low oral bioavailability have limited its clinical application for other diseases. Therefore, improving its water solubility and bioavailability is a prerequisite for addressing the limitations of asiatic acid in clinical use. This review summarizes the pharmacological mechanisms of action of asiatic acid and explains the reasons for its limited clinical application. This review describes methods to improve bioavailability through structural modifications of asiatic acid and the development of new formulations. It also focuses on enhancing the pharmacological effects of asiatic acid through the development and utilization of novel formulations such as nanoformulations and hydrogel formulations, providing a theoretical basis for the clinical translation of asiatic acid and the further research and development of asiatic acid-based drugs. Full article

The mitigation of early-age shrinkage and thermal cracking remains a pressing challenge in mass concrete structures. This study introduces a novel temperature-control admixture (TCA), formulated with gel-forming inorganic compounds, designed to suppress internal temperature rise while improving the mechanical stability of fly ash concrete. Four concrete mixes with TCA dosages of 0, 0.05, 0.10, and 0.15% were experimentally evaluated under controlled environmental conditions. Results show that the optimal dosage of 0.10% achieved a 27.3% reduction in shrinkage and a 12.2% increase in compressive strength at 28 days compared to the control. Furthermore, existing shrinkage models (Eurocode 2, fib Model Code 2010, AS 3600, Bazant B4) consistently overestimated shrinkage by up to 294% due to their inability to capture TCA-induced modifications in hydration and moisture transport. To address this, a modified prediction model incorporating admixture and fly ash–dependent correction factors was proposed, reducing the mean prediction error to just 10% and achieving a coefficient of variation as low as 0.08. This work provides a semi-empirical modeling approach that captures the influence of microencapsulated TCAs on concrete shrinkage and offers useful insights for the design and optimization of advanced concrete systems. Full article

To study the mechanical properties and modification mechanism of thermosetting polyurethane (PU)-modified asphalt, the effects of polyurethane dosage on the workability of polyurethane-modified asphalt were analyzed by means of rotational viscosity tests. The mechanical properties of polyurethane-modified asphalt with different polyurethane dosages were explored using tensile tests and dynamic mechanical analysis (DMA). In addition, the thermodynamic behavior and micromorphology of polyurethane-modified asphalt were also thoroughly investigated using the test results of differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The results showed that PU obtained the optimum workability when the polyurethane dose was 50%: at 120 min, its rotational viscosity was 1005 cp, which was lower than 2800 cp (40% PU) and 760 cp (60% PU). Additionally, the results of fracture elongation and fracture strength indicated that the PU-modified asphalt had good flexibility and strength. Compared with base asphalt, the tensile strength of 50% PU-modified asphalt increased by 509%, which was significantly higher than 157% (40% PU) and more balanced than 897% (60% PU) in terms of strength and flexibility. Added PU can significantly improve the elasticity of asphalt at high temperatures, while increasing the proportion of asphalt adhesive components, enhancing the deformation ability and temperature stability of asphalt. As the dose of PU increases, the interface between asphalt and PU blended more fully, and the surface became smoother. When the dose of PU was 50% or more, the interface between asphalt and PU was well integrated with a smooth and flat surface, forming a more uniform and stable cross-linked network structure. Full article

This paper evaluates the synergistic effect of polyvinyl alcohol (PVA) fibers and nanosilica (nS) on the mechanical behavior and deformation properties of engineered cementitious composites (ECCs). ECCs have gained a reputation for high ductility, crack control, and strain-hardening behavior. Nevertheless, the next step is to improve their performance even more through nano-modification and fine-tuning of fiber dosage—one of the major research directions. In the experiment, six types of ECC mixtures were made by maintaining constant PVA fiber content (0.5, 1.0, 1.5, and 2.0%), while the nanosilica contents were varied (0, 1, 2, 3, and 5%). Stress–strain tests carried out in the form of compression, together with unrestrained shrinkage measurement, were conducted to test strength, strain capacity, and resistance to deformation, which was highest at 80 MPa, recorded in the concrete with 2% nS and 0.5% PVA. On the other hand, the mixture of 1.5% PVA and 3% nS had the highest strain result of 2750 µm/m, which indicates higher ductility. This is seen to be influenced by refined microstructures, improved fiber dispersion, and better fiber–matrix interfacial bonding through nS. In addition to these mechanical modifications, the use of nanosilica, obtained from industrial byproducts, provided the possibility to partially replace Portland cement, resulting in a decrease in the amount of CO₂ emissions. In addition, the enhanced crack resistance implies higher durability and reduced long-term maintenance. Such results demonstrate that optimized ECC compositions, including nS and PVA, offer high performance in terms of strength and flexibility as well as contribute to the sustainability goals—features that will define future eco-efficient infrastructure. Full article

The number of newly developed substances with poor water solubility continually increases. Therefore, specialized formulation strategies are required to overcome the low bioavailability often associated with this property. This review provides an overview of novel physical modification strategies discussed in the literature over the past decades and focuses on oral dosage forms. A distinction is made between ‘brick-dust’ molecules, which are characterized by high melting points due to the solid-state properties of the substances, and ‘grease-ball’ molecules with high lipophilicity. In general, the discussed strategies are divided into the following three main categories: drug nanoparticles, solid dispersions, and lipid-based formulations. Full article

Waste cooking oil (WCO) plays different roles in modified asphalt and significantly affects the performance of the binder. However, a systematic comparative study is still lacking in the existing research. This study investigates the effects of WCO used as a swelling agent for rubber powder (RP) and as a compatibilizer in rubber powder-modified asphalt (RPMA) on the performance of modified asphalt. Specifically, the microstructure and functional groups of WCO-coated RP were first characterized. Then, RPMAs with different RP dosages were prepared, and the storage stability and rheological properties of RPMAs were thoroughly investigated. Finally, the flue gas emission characteristics of different RPMAs at 30% RP dosing were further analyzed, and the corresponding inhibition mechanisms were proposed. The results showed that the RP coated by WCO was fully solubilized internally, and the WCO formed a uniform and continuous coating film on the RP surface. Comparative analysis revealed that when WCO was used as a swelling agent, the prepared S-RPMA exhibited superior storage stability. At a 30% RP content, the softening point difference value of S-RPMA was only 1.8 °C, and the reduction rate of the segregation index reached 40.91%. Surprisingly, after WCO was used to coat the RP, the average concentrations of VOCs and H₂S in S-RPMA30 were reduced to 146.7 mg/m³ and 10.6 ppm, respectively, representing decreases of 20.8% and 22.1% compared with the original RPMA30. These findings demonstrate that using WCO as a swelling agent enhances both the physical stability and environmental performance of RPMA, offering valuable insights for the rational application and optimization of WCO incorporation methods in asphalt modification. It also makes meaningful contributions to the fields of coating science and sustainable materials engineering. Full article

The efficient depolymerization of lignin has become a key challenge in the preparation of high-value-added chemicals. Graphitic carbon nitride (g-C₃N₄)-based photocatalytic system shows potential due to its mild and green characteristics over other depolymerization methods. However, its inherent defects, such as a wide band gap and rapid carrier recombination, severely limit its catalytic performance. In this paper, a g-C₃N₄ modification strategy of K⁺ doping and surface alkalinization is proposed, which is firstly applied to the photocatalytic depolymerization of the lignin β-O-4 model compound (2-phenoxy-1-phenylethanol). K⁺ doping is achieved by introducing KCl in the precursor thermal polymerization stage to weaken the edge structure strength of g-C₃N₄, and post-treatment with KOH solution is combined to optimize the surface basic groups. The structural/compositional evolution of the materials was analyzed by XRD, FTIR, and XPS. The morphology/element distribution was visualized by SEM-EDS, and the optoelectronic properties were evaluated by UV–vis DRS, PL, EIS, and transient photocurrent (TPC). K⁺ doping and surface alkalinization synergistically regulate the layered structure of the material, significantly increase the specific surface area, introduce nitrogen vacancies and hydroxyl functional groups, effectively narrow the band gap (optimized to 2.35 eV), and inhibit the recombination of photogenerated carriers by forming electron capture centers. Photocatalytic experiments show that the alkalinized g-C₃N₄ can completely depolymerize 2-phenoxy-1-phenylethanol with tunable product selectivity. By adjusting reaction time and catalyst dosage, the dominant product can be shifted from benzaldehyde (up to 77.28% selectivity) to benzoic acid, demonstrating precise control over oxidation degree. Mechanistic analysis shows that the surface alkaline sites synergistically optimize the C_β-O bond breakage path by enhancing substrate adsorption and promoting the generation of active oxygen species (·OH, ·O₂⁻). This study provides a new idea for the efficient photocatalytic depolymerization of lignin and lays an experimental foundation for the interface engineering and band regulation strategies of g-C₃N₄-based catalysts. Full article

The utilization of steel slag (SS), fly ash (FA), and ground granulated blast furnace slag (GGBFS) as soil additives in construction represents a critical approach to achieving resource recycling of these industrial by-products. This study aims to activate the SS-FA-GGBFS composite with a NaOH solution and Na₂CO₃ and employ the activated solid waste blend as an admixture for lateritic clay modification. By varying the concentration of the NaOH solution and the dosage of Na₂CO₃ relative to the SS-FA-GGBFS composite, the effects of these parameters on the activation efficiency of the composite as a lateritic clay additive were investigated. Results indicate that the NaOH solution activates the SS-FA-GGBFS composite more effectively than Na₂CO₃. The NaOH solution significantly promotes the depolymerization of aluminosilicates in the solid waste materials and the generation of Calcium-Silicate-Hydrate and Calcium-Aluminate-Hydrate gels. In contrast, Na₂CO₃ relies on its carbonate ions to react with calcium ions in the materials, forming calcium carbonate precipitates. As a rigid cementing phase, calcium carbonate exhibits a weaker cementing effect on soil compared to Calcium-Silicate-Hydrate and Calcium-Aluminate-Hydrate gels. However, excessive NaOH leads to inefficient dissolution of the solid waste and induces a transformation of hydration products in the modified lateritic clay from Calcium-Silicate-Hydrate and Calcium-Aluminate-Hydrate to Sodium-Silicate-Hydrate and Sodium-Aluminate-Hydrate, which negatively impacts the strength and microstructural compactness of the alkali-activated solid waste composite-modified lateritic clay. Full article

The construction industry’s escalating environmental footprint, coupled with the underutilization of construction waste streams, necessitates innovative approaches to sustainable material design. This study investigates the dual functionality of recycled clay brick powder (RCBP) as both a supplementary cementitious material (SCM) and an alkali–silica reaction (ASR) inhibitor in hybrid mortar systems incorporating recycled glass (RG) and recycled clay brick (RCB) aggregates. Leveraging the pozzolanic activity of RCBP’s residual aluminosilicate phases, the research quantifies its influence on mortar durability and mechanical performance under varying substitution scenarios. Experimental findings reveal a nonlinear relationship between RCBP dosage and mortar properties. A 30% cement replacement with RCBP yields a 28-day activity index of 96.95%, confirming significant pozzolanic contributions. Critically, RCBP substitution ≥20% effectively mitigates ASRs induced by RG aggregates, with optimal suppression observed at 25% replacement. This threshold aligns with microstructural analyses showing RCBP’s Al³⁺ ions preferentially reacting with alkali hydroxides to form non-expansive gels, reducing pore solution pH and silica dissolution rates. Mechanical characterization reveals trade-offs between workability and strength development. Increasing RCBP substitution decreases mortar consistency and fluidity, which is more pronounced in RG-RCBS blends due to glass aggregates’ smooth texture. Compressively, both SS-RCBS and RG-RCBS mortars exhibit strength reduction with higher RCBP content, yet all specimens show accelerated compressive strength gain relative to flexural strength over curing time. Notably, 28-day water absorption increases with RCBP substitution, correlating with microstructural porosity modifications. These findings position recycled construction wastes and glass as valuable resources in circular economy frameworks, offering municipalities a pathway to meet recycled content mandates without sacrificing structural integrity. The study underscores the importance of waste synergy in advancing sustainable mortar technology, with implications for net-zero building practices and industrial waste valorization. Full article

To address the deficiencies of traditional emulsified asphalt-pavement maintenance material in cohesive strength, high-temperature rutting resistance, as well as adhesion to aggregates, this study developed waterborne epoxy resin-modified emulsified asphalt (WEA) binders using a two-component waterborne epoxy resin (WER) and systematically investigated their modification mechanisms and pavement performance. The results indicated that WER emulsions and curing agents could polymerize to form epoxy resin within the emulsified asphalt dispersion medium, with the modification process dominated by physical interactions. When the WER content exceeded 12%, a continuous modifier network structure was established within the emulsified asphalt. The epoxy resin formed after curing could significantly increase the polarity component of the binder, thereby increasing the surface free energy. The linear viscoelastic range of the WEA binder exhibited a negative correlation with the dosage of the WER modifier. Notably, when the WER content exceeded 6%, the high-temperature stability (rutting resistance and elastic recovery performance) of the binder was significantly enhanced. Concurrently, stress sensitivity and frequency dependence gradually decrease, demonstrating superior thermomechanical stability. Furthermore, WER significantly enhanced the interfacial interaction and adhesion between the binder and aggregates. However, the incorporation of WER adversely affects the low-temperature cracking resistance of the binder, necessitating strict control over its dosage in practical applications. Full article