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The Stöber method is one of the most important and fundamental processes for the synthesis of inorganic (nano)materials but has the drawback of using a large amount of organic solvent. Herein, ethanol was used as an example to explore if the organic solvent in a typical Stöber method can be omitted. It was found that ethanol increases the particle size of the obtained silica spheres and aids the formation of uniform silica particles rather than forming a gel. Nevertheless, the results indicated that an organic solvent in the initial synthesis mixture is not indispensable. An initially immiscible synthesis method was discovered, which can replace the organic solvent‐based Stöber method to successfully synthesize silica particles with the same size ranges as the original Stöber process without addition of organic solvents. Moreover, this process can be of further value for the extension to synthesis processes of other materials based on the Stöber process. [ABSTRACT FROM AUTHOR]

The low oral bioavailability of active pharmaceutical ingredients in aqueous media causes to partial absorption through the gastrointestinal tract. Increasing surface area by particle size reduction has been accomplished to overcome these challenges. In this study, Aprepitant (APT) nanoparticles were prepared using a green solvent anti-solvent precipitation method based on subcritical water (SW) technology. Effects of three different parameters such as SW temperature (368.15–388.15 K), anti-solvent temperature (273.15–293.15 K), and polyethylene glycol concentration (0.02–0.04 wt%) were studied on the size and morphology of the produced nanoparticles. As the next step, optimization of the process was performed using the response surface Box-Behnken design (BBD), and optimum operational conditions were obtained as follows: SW temperature (388.15 K), anti-solvent temperature (283.15 K), and polyethylene glycol concentration (0.04 wt%). The results revealed a significant decline in the size of the precipitated particle by subcritical water-based technologies (5.0 nm, on average), as compared to the unprocessed drug particles (30 μm, on average). Green SW-based technologies are proposed for the preparation of APT nanoparticles with no requirement for organic solvents and post-processing purification stages. [Display omitted] • Drug original particles were nanosized using subcritical water anti-solvent technology, for the first time. • Influences of solvent temperature, anti-solvent temperature and PEG concentration were investigated. • Optimization of the process was performed using the response surface Box-Behnken design (BBD). • Mean particle size of aprepitant has been reduced from its original 30 μm to 5 nm. [ABSTRACT FROM AUTHOR]

[Display omitted] • The molecular mechanism of TILLPS was proposed. • The TILLPS-based design strategy for spherical particles was constructed. • Four high-performance spherical particles were prepared in water. • The solid structure of particles was controlled using intermolecular interactions. • Spherical particles have excellent filtration properties and tableting performance. In the pharmaceutical and fine chemical industries, spherical particles are highly valuable due to their numerous applications; however, they are hindered by traditional methods requiring intricate devices, high energy consumption, and biohazardous solvents. In this study, we constructed a strategy for the design of spherical particles based on thermal-induced liquid–liquid phase separation at the microscopic molecular level. Based on this strategy, high-performance spherical particles were successfully prepared in water by a simple heating-quenching operation. Moreover, this strategy could also control the solid structure of particles by utilizing intermolecular interactions to meet the requirements of various application scenarios. In the case of fenofibrate, the equipment was simplified, the use of organic solvents was avoided, and the powder properties, filtration properties, and tableting performance of the product were significantly enhanced compared to those reported literature. This work elucidated the design and green production of new crystalline/amorphous materials with versatile functions. [ABSTRACT FROM AUTHOR]

Under organic solvent-free conditions, a quick, easy, small-scale sample preparation followed by an isocratic mobile phase HPLC for quantifying tetracycline (TC) and its 4-epimer, 4-epi-tetracycline (4eTC), in cow’s milk was described in this paper. The sample preparation could be made only homogenization using a handheld ultrasonic-homogenizer with deproteining aqueous solution followed by filtration with the disposable unit. For determination and identification of analyte, an Inertsil WP300 C4 and isocratic 100% aqueous mobile with photodiode array detector were used. The method validation data were well within the international analytical method acceptance criteria. The total time required for the analysis of one sample was less than 7 min. In all the process, no organic solvents were used. The present method may be proposed as an international harmonized analytical method for routine residue monitoring of TC and 4eTC in cow’s milk.

• Subcritical water is used as the solvent for processing of drug nanoparticles. • The use of organic solvents is eliminated by using cold water as anti-solvent. • The nanopharmaceuticals exhibit high dissolution rate. Nanonization of poorly water-soluble drugs offers an efficient approach for enhancing the bioavailability of drugs where the solubility and dissolution rate are the main limitations. The solvent anti-solvent precipitation methods have been the most straightforward technique for producing ultrasmall drug nanoparticles with narrow size distributions. By using subcritical water (SBCW) as the solvent, the use of organic solvents could be eliminated, providing a green route to nanopharmaceuticals. In this review, we aim to give a comprehensive overview and latest progress on SBCW processing for nanoparticles of poorly water-soluble drug compounds. The effects of processing parameters and stabilizers on the properties of the nanoparticles are summarized. Perspectives on existing challenges and opportunities for scale-up and commercialization of the SBCW technology are discussed. [ABSTRACT FROM AUTHOR]

We prepared microcapsules through an organic solvent‐free interfacial polymerization method, which avoids the release of volatile organic compounds arising from conventional interfacial polymerization methods for microencapsulation. These microcapsules have single and narrow particle size distribution and are spherical pellets with smooth and intact shell, and own excellent biodegradability. Additionally, these biodegradable microcapsules have a higher encapsulation efficiency compared with the microcapsules prepared through conventional interfacial polymerization method and possess sustained and controlled release of core materials. [ABSTRACT FROM AUTHOR]

Hollow fiber membranes are traditionally manufactured using the spinning process, which takes advantage of the phase separation/inversion for the creation of a porous structure. In this work, the use of melt extrusion led to the fabrication of hollow fiber membranes without the use of organic solvents. Following post-treatment, the fabricated partially dense fibers are transformed into porous fibers. In detail, ternary blends of polyethersulfone/poly(ethylene glycol)/poly(N -vinyl pyrrolidone) (PESU/PEG/PVP) were developed by combining a solvent-free liquid mixture of PEG/PVP into PESU. Using a single screw extruder, this blend was melted and extruded using an annular slit nozzle where PEG functioned as a plasticizer, i.e., decreased processing temperatures, while PVP aided in retaining the hollow fiber geometry. These hollow fibers were comprised of uniformly closed pores, occurring due to the expansion and formation of bubbles of evaporating PEG nucleated by PVP during extrusion. By immersing these fibers into an aqueous solution of sodium hypochlorite (NaOCl), PEG and PVP were removed, which led to an open porous structure with pore sizes between 100 nm and 1 μm throughout the membrane. The outer surfaces of the hollow fibers were found to contain a higher PVP content than the inner surface. As PVP and PESU are miscible, i.e., blended in a single phase, treatment with NaOCl led to the creation of open pores on the outer surface with pore sizes between 10 and 150 nm, thus deeming the outer surface functional as a separation layer. The effect of blend composition, extrusion settings, and post-treatment parameters on membrane morphology, water flux, thermal characteristics, and tensile strength was studied, while after the modification, near-pristine PESU membranes were pursued. A water-flux of 28 L/h m2 bar and a molecular weight cut-off (MWCO) of 90%, 75%, and 40% for poly(ethylene oxide) of an average of 1000 kDa, 400 kDa, and 100 kDa molecular weight, respectively, proved that via extrusion it is possible to produce hollow fiber membranes for ultrafiltration without the use of organic solvents. [Display omitted] • Porous hollow fiber membranes from polymer blend of PESU/PEG/PVP via melt extrusion without the use of organic solvent. • Melt extruded hollow fiber membranes capable to a water flux of 28 L/h m2. • Molecular weight cut-off of 90% for PEG 1000 kDa, 75% for PEG 400 kDa and 40% for PEG 100 kDa. • Methodology set an improvement towards sustainability due to the absence of organic solvents. [ABSTRACT FROM AUTHOR]

• A highly efficient Zr-MOF/H 2 O 2 catalytic system was developed for selective aniline oxidation. • The impact of metal, organic linker, and pore size on catalytic performance was studied. • Quantitative yield of azoxybenzene and high H 2 O 2 efficiency was achieved. • The H 2 O 2 activation mechanism based on bridging Zr-OH-Zr sites was proposed. A highly efficient and organic solvent-free synthetic strategy for the selective oxidation of anilines to azoxybenzenes was developed by employing porous Zr-MOFs as catalysts in aqueous hydrogen peroxide solution. The impact of cluster nodes, pore size, and linker functionalities on the catalytic performance of Zr-MOFs was fully evaluated and discussed. Featuring abundant bridging Zr-OH-Zr catalytic sites and confined microenvironments, the pristine UiO-66(Zr) could create abundant reactive oxygen species (ROS) with high H 2 O 2 efficiency, affording quantitative yield of azoxybenzene under mild conditions. Furthermore, the UiO-66(Zr)/H 2 O 2 heterogeneous catalytic system exhibited broad and size-selective substrate scope and excellent stability in consecutive catalytic cycles. Mechanism studies demonstrated that the azoxybenzenes were produced through radical pathway on bridging Zr-OH-Zr sites. This study provided alternative strategies exploiting green catalytic systems with porous MOFs, which might further expand the potential application of the MOFs family. [Display omitted] [ABSTRACT FROM AUTHOR]

Poly(2-methoxyethyl acrylate) (pMEA) microspheres are prepared through facile free-radical polymerization in water without additives and impurities, such as surfactants, other polymers, and organic solvents, which are usually used to synthesize pMEA chains. Clean and pure (non-factionalized and non-cross-linking) pMEA microspheres exhibit plasma–protein adsorption resistances on their surface regardless of their charged state. They are characterized in terms of the adsorbed amounts of proteins at pH 7. In addition, these soft and deformable pMEA microspheres are suitable for forming substrates coated with pMEA microspheres and free-standing films by injecting pMEA dispersion and evaporating the aqueous medium through fusion between the pMEA chains at the surface without the precoating agent and cross-linker. These pMEA coatings have been used till now in artificial heart/lung fabrication and metal products manufacturing by casting organic solvents such as 1,4-dioxane, toluene, and methanol and dissolving pMEA chains prepared using conventional solution polymerization. In this study, bioinert coatings and adhesive and transferable films are easily obtained due to the rubber-like properties of the pMEA microspheres and stable in mild and biocompatible conditions even when these impurities are not used completely, allowing us to provide a guideline for potential pMEA bioapplications such as coatings, films, barriers, and implant devices. [ABSTRACT FROM AUTHOR]

The use of biomaterial scaffolds has been an enormous field of research in tissue engineering, where the aim is to use graft materials for assisting the human body in recovering lost functions. Currently, there are many ways biomaterial scaffolds can be fabricated; however, many of these techniques involve the use of toxic organic solvents during the process. As biocompatibility is one of the mandatory requirements in designing a successful scaffold, there is an interest in fabricating scaffolds that are completely organic solvent-free. This paper describes the development and characterization of novel micro-/nano-fibrillar composites (MFC/NFC) that can produce scaffolds which are completely free from organic solvents. In this research, the cytocompatibility of these materials have been tested in vitro using mouse osteoblast-like cells and primary rat tenocytes, where cell numbers increase over the culture period, demonstrating the material viability. Gene expression analysis of primary rat tenocytes on MFC/NFC scaffolds demonstrate tenocytic behavior, and histology studies show an increase in cell formation on NFC scaffolds. This study establishes the potential of using the MFC/NFC technique to produce completely organic solvent-free scaffolds capable of hosting musculoskeletal cells, in the hope of providing a graft material for non-union skeletal fractures and rotator cuff repairs. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1393-1404, 2017. [ABSTRACT FROM AUTHOR]

A highly efficient catalytic method for aerobic oxyiodination of various phenols catalysed by copper(II) nitrate was achieved under mild conditions using I 2 as an iodinating reagent, molecular oxygen as an oxidant, and water as a solvent. The catalyst shows not only high activity for phenols with either electron-donating or electron-withdrawing groups, but also a remarkable selectivity for the formation of para -iodo substituted phenols. This study offers a green method for iodination of aromatic phenols with high atom economy. [ABSTRACT FROM AUTHOR]

With the development of surface science, surface with special wettability, such as reversible or gradient, gradually becomes the focus of the field of science now. Here, via a facile, green organic solvent-free route, we have fabricated superhydrophobic hybrid MWCNTs membrane on mixed cellulose ester filter with great flexibility and tailorability. Importantly, induced by acetic acid vapour and NH 3 vapour without external energy, wettability of it can be reversibly switched between superhydrophobic (low adhesion) to hydrophobic (high adhesion). Furthermore, hybrid MWCNTs membrane can achieve diverse range of gradient wettability. The principle of theory behind phenomenon also has been explained through surface chemical composition and microscopic surface topography by means of Field-emission scanning electron microscope (FESEM) images, X-ray photoelectron spectroscopy (XPS) and Fourier transformer infrared spectra (FTIR) spectroscopy. This work has solved some critical problems in this field. The limitations and potential application of our work also be summarized. [ABSTRACT FROM AUTHOR]

Poorly water-soluble drugs often suffer from limited or irreproducible clinical response due to their low solubility and dissolution rate. In this study, organic solvent-free solid dispersions (OSF-SDs) containing telmisartan (TEL) were prepared using polyvinylpyrrolidone K30 (PVP K30) and polyethylene glycol 6000 (PEG 6000) as hydrophilic polymers, sodium hydroxide (NaOH) as an alkalizer, and poloxamer 188 as a surfactant by a lyophilization method. In-vitro dissolution rate and physicochemical properties of the OSF-SDs were characterized using the USP I basket method, differential scanning calorimetry (DSC), X-ray diffractometry (XRD) and fourier transform-infrared (FT-IR) spectroscopy. In addition, the oral bioavailability of OSF-SDs in rats was evaluated by using TEL bulk powder as a reference. The dissolution rates of the OSF-SDs were significantly enhanced as compared to TEL bulk powder. The results from DSC, XRD showed that TEL was molecularly dispersed in the OSF-SDs as an amorphous form. The FT-IR results suggested that intermolecular hydrogen bonding had formed between TEL and its carriers. The OSF-SDs exhibited significantly higher AUC0-24 h and Cmax, but similar Tmax as compared to the reference. This study demonstrated that OSF-SDs can be a promising method to enhance the dissolution rate and oral bioavailability of TEL. [ABSTRACT FROM AUTHOR]

[Display omitted] • The intrinsic mechanism of ethyl vanillin oiling-out process is revealed. • A green and efficient spherical particles preparation technology is developed. • The spherical particles of ethyl vanillin present excellent powder properties. • The spherical products have sustained release and anti-caking function. Ethyl vanillin is an important synthetic flavor that occupies a large market share in food additives. However, the shortcomings in terms of too fast aroma release rate and poor powder properties have severely limited its further application. In this work, the intrinsic mechanism of ethyl vanillin oiling-out process is revealed with the help of process analytical technologies. Further, a green and efficient spherical particles preparation technology is developed by constructing the oiling-out phase diagram of ethyl vanillin in the aqueous solution of sodium chloride. The ethyl vanillin spherical product has excellent powder properties with high bulk density (0.74 g/cm3), good sphericity (93.4 %), high flowability (29°), high yield (>95 %) and adjustable particle size distribution. More importantly, the spherical product exhibits 57.9 % lower aroma release rate at 323.15 K and 1400 % higher critical caking cycle compared to irregularly shaped powder, which confirms its sustained release and anti-caking function. [ABSTRACT FROM AUTHOR]

Molybdenum complexes of type [MoO 2 L] n (L = tridentate ONO Schiff base ligands based on the salicylidene-2-aminophenolato structure) have been synthesized and used as catalysts for the solvent-free epoxidation of olefins. The effect of donor (diethylamino) and/or acceptor (nitro) substituents has been studied. [ABSTRACT FROM AUTHOR]

Highlights: [•] Organic solvent-free water-developable sugar resist was demonstrated. [•] Sugar resist led to the well-patterned 100nm lines for green lithography. [•] Sugar resist indicated acceptable CF4 etch selectivity with hardmask material. [ABSTRACT FROM AUTHOR]

Abstract: The expeditious and solvent-free approach that involves the exposure of neat reactants to microwave (MW) irradiation in conjunction with the use of supported catalysts was described. A simple one-pot and green reaction of methylpyridine derivatives and phthalic anhydride derivatives on the surface of a nano silica gel impregnated with BF3 as solid supported catalysts under microwave irradiation without any solvent according to green chemistry was developed. The salient features of these high yield protocols are the enhanced reaction rates, greater selectivity and the experimental ease of manipulation. [Copyright &y& Elsevier]

Abstract: A series of size-controllable hierarchically nanostructured magnetic hollow spheres (MHS) (250–2330nm) have been fabricated by using the hard-template method involving the coprecipitation of ferrite precursor over the pre-synthesized polystyrene spheres with varied sizes under organic solvent-free conditions followed calcinations. The SEM, TEM and HRTEM results indicate that the primary nanoparticles constructing hierarchically nanostructured MHS clearly show the template sphere size-dependent changes in morphologies and stacking modes from disorderly stacked globular and nanorodlike mixed particles, to orderly perpendicularly oriented nanorodlike particles, and to compact horizontally arranged nanospindle particles as the template size is increased. The N2 adsorption–desorption data reveal that the MHS spheres have a high BET surface area (48–83m2/g) and large pore volumes (0.37–0.66cc/g). The vibration sample magnetization analysis shows that the MHS spheres have moderate magnetization saturation of 24–37emu/g. The adsorption results show that the BSA adsorbance is greatly affected by the varied morphologies and stacking modes of primary nanoparticles constructing the MHS spheres and the maximum adsorption occurs on the MHS spheres mainly comprised of perpendicularly oriented nanorodlike primary particles. [Copyright &y& Elsevier]

Abstract: Silica sulfuric acid was found to be an efficient, reusable and environment-friendly catalyst for fast hydrolysis of various isobenzofuranone to corresponding 2-ketomethylquinoline derivatives in a high yield under solvent-free using microwave irradiation. As the activator of silica sulfuric acid the wet SiO2 was chosen. The reactions in conventional conditions were compared with the microwave assisted reactions. This approach can prove beneficial since the recovery of solvents from conventional reaction systems always results in some losses. [ABSTRACT FROM AUTHOR]

Abstract: All the works reported about oxidative cleavage of olefins by the RuCl3/NaIO4 catalytic system have been performed in biphasic water/organic solvent(s). The first organic solvent-free oxidation of Cbond by 2% RuCl3/4.1equiv NaIO4/H2O is described here using both the emulsifier Aliquat® 336 and 20kHz ultrasonic irradiation. [Copyright &y& Elsevier]

Abstract: Methyltrioxorhenium/3-methylpyrazole has proved to be an efficient catalytic system for epoxidation of alkenes with aqueous 35% H2O2 in excellent yields under organic solvent-free conditions. The yields of epoxides by the organic solvent-free epoxidation are comparable to those using CH2Cl2 as the organic solvent. The epoxidations of simple alkenes under organic solvent-free conditions are slower than those in CH2Cl2, while the epoxidations of alkenols such as citronellol are faster than those in CH2Cl2. [Copyright &y& Elsevier]

An efficient and reusable heterogeneous catalyst with oxime‐derived palladacycle immobilized in an ionic liquid brush has been synthesized and an environmentally‐friendly procedure have been developed for coupling aryl iodides and bromides with acrylic acid. These reactions were conducted in neat water under aerobic conditions with water‐insoluble or even solid aryl halides and they proceeded smoothly and cleanly without any organic co‐solvent or other additives. The ionic liquid brush could be easily recovered and reused at least five times without significant loss of activity. The protocol has the advantages of excellent yields, environmental friendliness, and catalyst recyclability. [ABSTRACT FROM AUTHOR]

• Novel Lip-PTX/BSA NPs were fabricated via modified thin-film method. • The fabrication process avoided direct contact of BSA with toxic organic solvents. • The fabrication process eliminated organic solvent residual. • The NPs exhibited excellent colloidal stability and sustained release manner. • The NPs showed effective in vitro/vivo antitumor efficacy. Organic solvents have been reported to exert certain influence on the structure and drug loading efficiency of albumin. It is urgent to develop organic solvent-free albumin-based paclitaxel nanoparticles for effective anticancer therapy. In this study, novel PTX liposome-albumin composite nanoparticles (Lip-PTX/BSA NPs) aimed at avoiding the direct contact of albumin with toxic organic solvents and enhancing the colloidal stability of the formulation were prepared. To methodically evaluate the impacts of multifarious factors on the critical characteristics of the nanoparticles, Box-Behnken design was applied in the formulation optimized process. Ratio of drug-phosphatidylcholine (EPC), ratio of drug-BSA and pH of the media were chosen as the independent variables, while particle size and drug-loading content (DLC) loss rate were applied as the selected response variables. A quadratic model fitted best to describe the data with maximal lack-of-fit p-value and minimum sequential p-value. Three-dimension surface figures were utilized to describe the correlation of independent variables with response variables. Optimized formulation of the nanoparticles with size of 116.2 ± 2.0 nm and zeta potential of -18.4 ± 1.01 mV were obtained with a high encapsulation efficiency of 99.8%. PTX was involved physical interaction with the excipient during the preparation process of the nanoparticles. The release of PTX from Lip-PTX/BSA NPs exhibited a sustained release manner compared to albumin-bound PTX (nab-PTX) and Taxol. Besides, Lip-PTX/BSA NPs presented enhanced in vitro cytotoxicity against 4T1 cells due to highly nonspecific internalization in the cytoplasm. Simultaneously, Lip-PTX/BSA NPs showed effective in vivo antitumor efficacy against 4T1 bearing BALB/c mice, while no apparent adverse effect was observed by histological section and blood biochemical analysis. In conclusion, the novel Lip-PTX/BSA NPs could be applied as a promising drug delivery system for PTX to exert efficient cancer curative effects in clinic. [ABSTRACT FROM AUTHOR]

Poorly water-soluble drugs often suffer from limited or irreproducible clinical response due to their low solubility and dissolution rate. In this study, organic solvent-free solid dispersions (OSF-SDs) containing telmisartan (TEL) were prepared using polyvinylpyrrolidone K30 (PVP K30) and polyethylene glycol 6000 (PEG 6000) as hydrophilic polymers, sodium hydroxide (NaOH) as an alkalizer, and poloxamer 188 as a surfactant by a lyophilization method. In-vitro dissolution rate and physicochemical properties of the OSF-SDs were characterized using the USP I basket method, differential scanning calorimetry (DSC), X-ray diffractometry (XRD) and fourier transform-infrared (FT-IR) spectroscopy. In addition, the oral bioavailability of OSF-SDs in rats was evaluated by using TEL bulk powder as a reference. The dissolution rates of the OSF-SDs were significantly enhanced as compared to TEL bulk powder. The results from DSC, XRD showed that TEL was molecularly dispersed in the OSF-SDs as an amorphous form. The FT-IR results suggested that intermolecular hydrogen bonding had formed between TEL and its carriers. The OSF-SDs exhibited significantly higher AUC0-24 h and Cmax, but similar Tmax as compared to the reference. This study demonstrated that OSF-SDs can be a promising method to enhance the dissolution rate and oral bioavailability of TEL.