Search Results (312)

Background/Objective: The high-shear granulator is considered an effective piece of equipment for layering pelletization because it enhances drug amorphization and improves drug dissolution. This study aimed to apply a high-shear granulator to prepare layered pellets containing a combination of hydrochlorothiazide and amlodipine besylate with improved physicochemical properties. Methods: Different molar ratios (2:1, 1:1, and 1:2) of the hydrochlorothiazide and amlodipine besylate mixture were deposited on the surface of the inert spheres of the microcrystalline cellulose (MCC) core by the mechanical effect of the high impeller speed. The resulting layered pellets were characterized using X-ray powder diffractometry (XRPD) and differential scanning calorimetry (DSC) to estimate the degree of the drug amorphization, and consequently a dissolution test was performed to determine the degree of the enhancement of the percentage of release. Additionally, micro-computed tomography (micro-CT) and a texture analyzer were used to determine the morphological characteristics and hardness of the resulting pellets, and then a stability study was performed. Results: On the basis of the micro-CT images, the MCC core was successfully loaded with a uniform layer of the drug combination at the pellet surface, which exhibited higher diameters than pure cellets. Furthermore, the drug combination in layered pellets was partially amorphized with a lower crystallinity percentage, a lower intensity, a broadening of the hydrochlorothiazide melting peak, and a higher cumulative release of both drugs with good stability, except pellets with a molar ratio of 1:2 that were recrystallized with a higher crystallinity percentage of 79.9%. Conclusions: Modifying the physical form and dissolution behavior of the hydrochlorothiazide and amlodipine besylate combination was achieved by single-step layering pelletization. Full article

Thermoplastic chitosan/microcrystalline cellulose (TPC/MCC) composite films were prepared by thermo-compression and are reported here for the first time. L-lactic acid (LLA) was used as a plasticizer in the formation of TPC. TPC films with varying LLA contents and the TPC/MCC composite films with different MCC contents were produced for evaluation. The physicochemical, mechanical, and antibacterial properties of the thermo-compressed TPC and TPC/MCC films were characterized. LLA enhanced thermal stability and crystallinity, improved film flexibility, and reduced the water solubility of the chitosan matrix. Incorporation of MCC further improved mechanical properties and decreased water dissolution. Tensile testing showed that the addition of 5 wt% MCC increased maximum tensile strength by 82% and Young’s modulus by 124%. All TPC and TPC/MCC films exhibited antibacterial activities against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Antibacterial efficacy decreased as MCC content increased to 20 wt%. These thermo-compressed TPC/MCC films can be tailored to display a range of properties by adjusting the contents of LLA and MCC, making them well suited for antibacterial food-packaging applications. Full article

This study aims to address the poor extensibility, brittleness, and limited hydration stability of pure sodium alginate (SA) hydrogels, which hinder their use in flexible, skin-adherent applications such as facial masks, by developing bio-based composites incorporating five representative functional additives: xanthan gum, guar gum, hydroxyethyl cellulose (HEC), poly(ethylene glycol)-240/hexamethylene diisocyanate copolymer bis-decyl tetradeceth-20 ether (GT-700), and Laponite^® XLG. Composite hydrogels were prepared by blending 1.5 wt% SA with 0.3 wt% of each additive in aqueous humectant solution, followed by ionic crosslinking using 3% (w/w) CaCl₂ solution. Physicochemical characterization included rotational viscometry, uniaxial tensile testing, ATR-FTIR spectroscopy, swelling ratio analysis, and pH measurement. Among them, the SA/XLG composite exhibited the most favorable performance, showing the highest viscosity, shear-thickening behavior, and markedly enhanced extensibility with an elongation at break of 14.8% (compared to 2.5% for neat SA). It also demonstrated a mean swelling ratio of 0.24 g/g and complete dissolution in water within one year. ATR-FTIR confirmed distinct non-covalent interactions between SA and XLG without covalent modification. The hydrogel also demonstrated excellent conformability to complex 3D surfaces, consistent hydration retention under centrifugal stress (+23.6% mass gain), and complete biodegradability in aqueous environments. Although its moderately alkaline pH (8.96) may require buffering for dermatological compatibility, its mechanical resilience and environmental responsiveness support its application as a sustainable, single-use skin-contact material. Notably, the SA/XLG composite hydrogel demonstrated compatibility with personalized fabrication strategies integrating 3D scanning and additive manufacturing, wherein facial topography is digitized and transformed into anatomically matched molds—highlighting its potential for customized cosmetic and biomedical applications. Full article

Objectives: Although 3D-printing has been identified as a promising technique for personalised medicine manufacturing, developing complex formulations that are suitable for the process can be challenging. This study evaluates the use of a mixture design for the targeted development of an optimised formulation designed for the 3D-printing of oral dosage forms containing the drug sertraline hydrochloride featuring immediate-release drug dissolution. Methods: The polymers Eudragit E PO, Kollidon 17 PF and hydroxypropyl cellulose were compared in simple screening experiments regarding their extrudability, printability and disintegration. A combination of Eudragit E PO and Kollidon 17 PF proved superior and therefore served as the basis for the mixture design. The resulting blends were processed via hot melt extrusion to produce filaments, which were then measured for bending stress using a 3-point-bending-test, and 3D-printed sample plates were used to determine the crystallinity index of sertraline hydrochloride using X-ray diffraction in a previously identified range with low interference from the other components. The formulation was optimised using statistically based models with the aim of minimising the bending stress to obtain flexible, process-robust filaments and simultaneously minimising the crystallinity index with the intention of improving the solubility of the drug by maximising its amorphous content. Results: The filaments made from the optimised formulation could be reliably printed, and the amorphous state of the active ingredient therein was confirmed. The oral dosage forms produced from these showed immediate release characteristics in an acidic medium. Conclusions: This study demonstrates the advantages of a mixture design for optimising complex formulations in a time- and resource-efficient way and could serve as a basis for other research groups to develop innovative, customisable drug delivery systems more effectively. Full article

Background/Objectives: To improve the therapeutic efficacy of albendazole (ABZ) for ileocolonic diseases, its low solubility at higher pH levels should be enhanced. Organic acids have been widely used as pH modifiers to improve the solubility of weakly basic drugs. To achieve an adequate effect of the acidic microenvironmental pH during the drug release, pH modifiers should not leach out from the formulation. In the present work, we aimed to demonstrate that 100% tartaric acid pellets (TAP) can be used as pH-modifier cores, providing an acidic microenvironmental pH to enhance the solubility of albendazole at a higher pH. Methods: This study develops multilayer-coated pellets using TAP as starter cores in a bottom-spray-configured fluidized bed apparatus. The drug-layered TAP were coated with time-dependent and pH-dependent layers. Results: The release of ABZ from tartaric acid-based coated pellets was enhanced compared to that from pellets with the same layering structure but with an inert core of sugar or microcrystalline cellulose (MCC). In vitro experiments showed that tartaric acid remained in the pellet core during the dissolution test at a pH 6.8 medium, which resulted in an enhanced release of albendazole at a higher pH. The application of a combination of time-dependent and pH-dependent polymers aimed not only to prevent the release of albendazole at lower pH levels but also to protect TAP from premature release from the formulation. Conclusions: The application of 100% ready-to-use tartaric acid pellets (TAP) with the applied combination of coatings enhanced the solubility of the weakly basic drug albendazole at higher intestinal pH. Full article

Background/Objectives: Hot-melt extrusion (HME) has gained prominence for the manufacture of sustained-release oral dosage forms, yet the application of wax-based matrices and their resilience to alcohol-induced dose dumping (AIDD) remains underexplored. This study aimed to develop and characterise wax-based sustained-release felodipine formulations, with a particular focus on excipient functionality and robustness against AIDD. Methods: Felodipine sustained-release formulations were prepared via HME using Syncrowax HGLC as a thermally processable wax matrix. Microcrystalline cellulose (MCC) and lactose monohydrate were incorporated as functional fillers and processing aids. The influence of wax content and filler type on mechanical properties, wettability, and drug release behaviour was systematically evaluated. Ethanol susceptibility testing was conducted under simulated co-ingestion conditions (4%, 20%, and 40% v/v ethanol) to assess AIDD risk. Results: MCC-containing tablets demonstrated superior sustained-release characteristics over 24 h, showing better wettability and disintegration. In contrast, tablets formulated with lactose monohydrate remained structurally intact during dissolution, overly restricting drug release. This limitation was effectively addressed through granulation, where reduced particle size significantly improved surface accessibility, with 0.5–1 mm granules achieving a satisfactory release profile. Ethanol susceptibility testing revealed divergent behaviours between the two filler systems. Unexpectedly, MCC-containing tablets showed suppressed drug release in ethanolic media, likely resulting from inhibitory effect of ethanol on filler swelling and disintegration. Conversely, formulations containing lactose monohydrate retained their release performance in up to 20% v/v ethanol, with only high concentrations (40% v/v) compromising matrix drug-retaining functionality and leading to remarkably increased drug release. Conclusions: This study highlights the pivotal role of excipient type and constitutional ratios in engineering wax-based sustained-release formulations. It further contributes to the understanding of AIDD risk through in vitro assessment and offers a rational design strategy for robust, alcohol-resistant oral delivery systems for felodipine. Full article

Cellulose nanocrystals possess unique properties such as high surface area and excellent biocompatibility. They can disrupt strong hydrogen bonds and other intermolecular forces that hinder the solubility of certain molecules thus enhancing the solubility of poorly soluble materials. The main challenge in formulating poorly soluble drugs lies in their limited therapeutic efficacy due to inadequate solubility and bioavailability. Therefore, an innovative approach such as using cellulose nanocrystals to enhance the solubility is highly needed. The aim of this research is to study the potential of ramie (Boehmeria nivea L. Gaud) as a source of cellulose nanocrystals in the development of microspheres for the solubility enhancement of poorly soluble drugs. Nanocrystalline cellulose was isolated from the ramie (Boehmeria nivea L. Gaud) by optimizing hydrolysis conditions with varying acid concentrations and reaction times. Characterizations were performed by measuring particle size, pH, and sulfate content, followed by morphological study by SEM, functional group analysis, and thermal analysis. The use of sulfuric acid in the hydrolysis process of flax cellulose at 45 °C, as the type of acid that gives the best results, at 50% acid concentration for 60 min produces cellulose nanocrystallines with a particle size of 120 nm, sulfate concentration density of 133.09 mmol/kg, crystallinity of 96.2%, and a yield of 63.24 ± 8.72%. Furosemide was used as the poorly soluble drug model and its solubility enhancement in the form of furosemide/RNCC microspheres was evaluated through saturated solubility testing and in vitro dissolution. This study demonstrated that RNCC could improve the solubility of furosemide, which contributes to developing sustainable drug formulations and eco-friendly delivery systems for poorly soluble drugs. Full article

To successfully prepare cellulose hydrogels through a dissolution–regeneration process, 60 wt% LiBr aqueous solution was used as a green solvent. Carboxyl groups were precisely introduced onto the surface of the cellulose hydrogels through a TEMPO-mediated oxidation reaction, while the three-dimensional network structure and open pore morphology were completely retained. This modification strategy significantly enhanced the loading capacity of the hydrogels with copper nanoparticles (Cu NPs). The experimental results show that the LiBr aqueous solution can efficiently dissolve cellulose, and the TEMPO oxidation introduces carboxyl groups without destroying the stability of the hydrogels. Cu NPs are uniformly dispersed and highly loaded on the surface of the hydrogel because of the anchoring effect of the carboxyl groups. Cu NP-loaded hydrogels exhibit excellent catalytic activity in the NaBH₄ reduction of 4-nitrophenol (4-NP). Cu NP-loaded hydrogels maintain their complete structure and good catalytic performance after five consecutive cycles. Moreover, Cu NP-loaded hydrogels demonstrate high efficiency in degrading organic dyes such as methyl orange and Congo red. This study successfully developed efficient, low-cost, and environmentally friendly Cu NP-loaded hydrogel catalysts through the synergistic effect of LiBr green solvent and TEMPO oxidation modification, providing a feasible alternative to noble metal catalysts. Full article

Ionic liquids (ILs) have attained considerable attention as cellulose solvents. Nevertheless, the detailed mechanism of cellulose dissolution in ILs is not clearly defined. It is crucial to recognize the role of the individual components of the ILs to fully understand this mechanism. During this study, the effect of alkyl chain length in imidazolium cation was examined using synthesized ILs which are composed of common acetate anion and imidazolium cations with different alkyl substituents. This study also aimed to investigate the odd–even effect of alkyl chain carbons. Furthermore, whereas most published investigations on cellulose dissolution in ILs used microcrystalline cellulose (MCC), which has a far lower degree of polymerization, in this study, cotton cellulose was used. During the dissolution experiments, cotton cellulose (5% w/w) was added to each IL, and the progress of the dissolution was monitored using polarized light microscopy (PLM). The regeneration of cellulose was performed by using water as the anti-solvent, and the regenerated cellulose was characterized by Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). During these experiments, it was noted that ILs with odd C3 and C5 carbon chains were less effective at dissolving cellulose than those with even C2 and C4 alkyl chains. Additionally, after regeneration, biomaterials for a variety of applications could be produced. Full article

Cellulose acetate butyrate (CAB) and cellulose acetate propionate (CAP) are biobased materials that are insoluble in water and present a potential alternative to fossil-based plastics. Solvent removal-induced in situ matrices are gaining attention as an innovative dosage form for localized drug delivery for periodontitis therapy. This study aims to develop levofloxacin hemihydrate (Lh)-loaded in situ matrices formed through solvent removal, incorporating various molecular weights (MWs) and concentrations of CAB and CAP. Increased MWs and higher concentrations of these cellulosic esters significantly improved formulation viscosity and injection force, contributing to enhanced phase inversion and greater matrix toughness. Microscopic analysis of interfacial phase changes revealed progressive thickening of the matrix over time, which was influenced by polymer concentration and limited solvent movement. The transformed matrices with high MW CAP and elevated CAB content demonstrated prolonged drug release, predominantly following first-order kinetics, suggesting drug dissolution and diffusion through the scaffold structure. CAB-based in situ matrices containing 15% and 20% polymer exhibited low viscosities suitable for injection, along with optimal gel formation for maintaining their shape, and adhered effectively to periodontal pockets. These matrices provided extended Lh release for up to 120 h and inhibited the growth of periodontopathic bacteria for over 15 days. Therefore, the developed Lh-loaded in situ matrices show promise as an effective treatment for periodontitis, warranting further research to explore their therapeutic potential. Full article

Activated carbon is a useful adsorbent for the removal of pollutants from the aqueous phase. In this study, an easy method to overcome the difficulty in separating activated carbon from a solution after adsorption has been developed. Cellulose-activated carbon gels with a high activated carbon content up to 70% in the total solids were successfully prepared via the dissolution–regeneration process of cellulose using a LiBr aqueous solution. Activated carbon suspended in a cellulose solution dissolved by heating with a LiBr aqueous solution was embedded into a gel directly formed by lowering the temperature of the cellulose solution. The cellulose-activated carbon gels exhibited large specific surface areas and sufficient mechanical properties. The adsorption capacity of methylene blue onto the cellulose-activated carbon gels proportionally increased with the increasing content of activated carbon. The cellulose-activated carbon gels maintained a high adsorption capacity even after repeated adsorption–desorption cycles, demonstrating their potential as reusable adsorbents. Full article

Bacterial cellulose (BC) is a highly pure and crystalline cellulose produced via bacterial fermentation. However, due to its chemical structure made of strong hydrogen bonds and its high molecular weight, BC can neither be melted nor dissolved by common solvents. Therefore, processing BC implies the use of very strong, often toxic and dangerous chemicals. In this study, we proved a green method to produce electrospun BC fibers by testing different ionic liquids (ILs), namely, 1-butyl-3-methylimidazolium acetate (BmimAc), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EmimTFSI) and 1-ethyl-3-methylimidazolium dicyanamide (EmimDCA), either individually or as binary mixtures. Moreover, γ-valerolactone (GVL) was tested as a co-solvent derived from renewable sources to replace dimethyl sulfoxide (DMSO), aimed at making the viscosity of the cellulose solutions suitable for electrospinning. A BmimAc and BmimAc/EmimTFSI (1:1 w/w) mixture could dissolve BC up to 3 w%. GVL was successfully applied in combination with BmimAc as an alternative to DMSO. By optimizing the electrospinning parameters, meshes of continuous BC fibers, with average diameters ~0.5 μm, were produced, showing well-defined pore structures and higher water absorption capacity than pristine BC. The results demonstrated that BC could be dissolved and electrospun via a BmimAc/GVL solvent system, obtaining ultrafine fibers with defined morphology, thus suggesting possible greener methods for cellulose processing. Full article

In seeking alternatives for reducing environmental damage, fabricating filtration membranes using biopolymers derived from agro-industrial residues, such as cellulose acetate (CA), partially dissolved with green solvents, represents an economical and sustainable option. However, dissolving CA in green solvents through mechanical agitation can take up to 48 h. An ultrasonic probe was proposed to accelerate mass transfer and polymer dissolution via pulsed interval cavitation. Additionally, ultrasound-assisted phase inversion (UAPI) on the external coagulation bath was assessed to determine its influence on the properties of flat sheet and hollow fiber membranes during phase inversion. Results indicated that the ultrasonic pulses reduced dissolution time by up to 98% without affecting viscosity (3.24 ± 0.06 Pa·s), thermal stability, or the rheological behavior of the polymeric blend. UAPI increased water permeability in flat sheet membranes by 26% while maintaining whey protein rejection above 90%. For hollow fiber membranes, UAPI (wavelength amplitude of 0 to 20%) improved permeability by 15.7% and reduced protein retention from 90% to 70%, with MWCO between 68 and 240 kDa. This report demonstrates the effectiveness of ultrasonic probes for decreasing the dissolution time of dope solution with green cosolvents and its potential to change the structure of polymeric membranes by ultrasound-assisted phase inversion. Full article

Cotton fiber, renewable natural cellulose, make up the largest portion of textile waste. The ionic liquid method has been successfully employed to regenerate waste colored cotton fabric in this study, offering a comprehensive approach to the recycling of waste cotton. The chemical recovery process for reclaimed cellulose materials is crucial for high-value recycling of waste cotton fabrics. In this study, waste and new, colored and white cotton fabrics were used as experimental subjects. The breaking strength, degree of polymerization, iodine adsorption equilibrium value, and crystallinity between old and new fabrics were investigated. Ionic liquid 1-allyl-3-methylimidazole chloride ([AMIM]Cl) and zinc chloride (ZnCl₂) were selected to dissolve decolorized waste cotton fabric. Optimal conditions for dissolving the fabric using [AMIM]Cl were investigated. The best dissolution conditions identified were DMSO at a ratio of 1:1 with a dissolution temperature of 110 °C over a duration of 120 min. Additionally, the optimal film formation parameters included a solution concentration of 6%, solidification time of 3 min, and solidification bath temperature of 0 °C. Regenerated cellulose films from both the ionic liquid system (A-film) and zinc chloride system (Z-film) were prepared. The characteristics of the film produced using the most advanced technology were systematically investigated and evaluated. The results of this study provide a crucial theoretical foundation for the recovery and regeneration of waste cotton fabrics. Full article

In this study, cellulose nanocrystals (CNs) were utilized to enhance the mechanical properties and sulfate corrosion resistance of engineered cementitious composites (ECCs). The results of compressive strength and uniaxial tensile tests demonstrated that the incorporation of CNs significantly improved the compressive strength, strain rate, tensile strength, and sulfate corrosion resistance of ECC specimens. Scanning electron microscopy (SEM) observations revealed that the addition of CNs facilitated the formation of increased amounts of ettringite and calcium silicate hydrate (C-S-H) in the matrix, enhancing the hydration degree of the cementitious system and increasing the overall density of the ECC structure. Molecular dynamics simulations were employed to investigate the interactions between CN, C-S-H, water molecules, and sulfate ions (SO₄²⁻) while also calculating the kinetic parameters of atoms at the interface. These simulations provided insights into the microstructural strengthening mechanism of CNs in improving the sulfate corrosion resistance of ECCs. The results indicated that CNs adsorb onto C-S-H via Ca-O and H-O coordination, forming a protective layer that inhibits the penetration of SO₄²⁻ and water molecules into the C-S-H structure. Additionally, CNs form hydrogen bonds with SO₄²⁻ and water molecules, which restricts their diffusion and reduces their coordination with the C-S-H interface and the dissolution of SO₄²⁻ and water to the hydration product, thereby enhancing the sulfate corrosion resistance of ECCs. Full article