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This work reports the synthesis method and various properties of four rod-like antiferroelectric (R) laterally substituted enantiomers, with or without fluorine atoms used as substituents in the benzene ring. The influence of fluorine substitution on the mesophase temperature range was determined. The synthesized compounds are three-ring rod-like smectics with a chiral center based on (R)-(−)-2-octanol. Their chemical and optical purity was checked using high-performance liquid chromatography (HPLC). Two newly synthesized enantiomers and three previously reported (R) enantiomers were used to formulate two antiferroelectric mixtures. The mesomorphic behavior was characterized by polarizing optical microscopy, differential scanning calorimetry, and X-ray diffraction (XRD). The helical pitch and tilt angle measurements were done using the selective light reflection phenomenon and the electro-optical method, respectively. All the enantiomers exhibit a wide temperature range of the antiferroelectric phase, with a high tilt angle. Furthermore, the enantiomer with lateral fluorine substitution in the ortho position has a very long helical pitch (more than 2.0 µm), relatively low enthalpy of melting point, and a tilt angle close to 45 degrees. The designed (R) enantiomers can be useful for formulating eutectic mixtures for further use in various devices, including photonics and optoelectronics. [ABSTRACT FROM AUTHOR]

Traditionally, rechargeable lithium metal battery systems relied on simple metal cationic species to enable metal nucleation and deposition. However, this mechanism is less applicable to room‐temperature rechargeable aluminum batteries (RABs), which utilize complex ionic species. This work takes advantage of two different MXenes, Mo2Ti2C3Tx and Ti3C2Tx, which have different metal‐termination group bond strengths, interlayer spacings, and surface termination compositions, to amplify and visualize the differences between two promising RAB electrolytes (i.e., urea/AlCl3 and EMImCl/AlCl3). This work allowed us to deduce the following: 1) despite lower coulombic efficiencies, smoother Al deposits are observed when the urea/AlCl3 electrolyte is used; 2) unknown side reactions occur in all the different scenarios, however, they are likely less reversible in the EMImCl/AlCl3 electrolyte; 3) metal‐halogen exchange reactions can occur in all scenarios, forming Al(OF)x and AlFx species; 4) the free urea in urea/AlCl3 electrolyte behaves differently from the urea in aqueous solutions. Overall, due to the characteristics of aluminum, RABs involve vastly different internal mechanisms, resulting in the need for audacious attempts toward system understanding. [ABSTRACT FROM AUTHOR]

Three different devices: ball mill, hot stage melting, and magic angle spinning (MAS) NMR rotor were used for the preparation of ethenzamide (ET) cocrystals with glutaric acid (GLU), ethylmalonic acid (EMA) and maleic acid (MAL) as coformers. In each case, well‐defined binary systems (ET:EMA, ET:GLU, ET:MAL) were obtained. The common features of the two solvent free methods of cocrystal formation (grinding, melting) are presented on the basis of arguments obtained by solid state NMR spectroscopy. Thermal analysis (Differential Scanning Calorimetry) proved that the eutectic phase arises over a wide range of molar ratios of components for each of the binary systems. NMR techniques, supported by theoretical calculations, allowed to provide details about the pathway of the reaction mechanism with atomic accuracy. It was found that the formation of ET cocrystals is a complex process that requires five steps. Each step has been recognized and described. Variable temperature 1D and 2D MAS NMR experiments allowed to track physicochemical processes taking place in a molten state. Moreover, it was found that in a multicomponent mixture consisting of all four components, ET, EMA, GLU, and MAL, ET in the molten phase behaves as a specific selector choosing only one partner to form binary cocrystals according to energy preferences. The process of exchange of coformers in binary systems during grinding, melting, and NMR measurements is described. The stabilization energies (Estab) and molecular electrostatic potential (MEP) maps computed for the cocrystals under discussion and their individual components rationalize the selection rules and explain the relationships between individual species. [ABSTRACT FROM AUTHOR]

The dissolution rate of the anti-HIV drug saquinavir base (SQV), a poorly water-soluble and extremely low absolute bioavailability drug, was improved through a eutectic mixture formation approach. A screening based on a liquid-assisted grinding technique was performed using a 1:1 molar ratio of the drug and the coformers sodium saccharinate, theobromine, nicotinic acid, nicotinamide, vanillin, vanillic acid, and piperine (PIP), followed by differential scanning calorimetry (DSC). Given that SQV-PIP was the only resulting eutectic system from the screening, both the binary phase and the Tammann diagrams were adapted to this system using DSC data of mixtures prepared from 0.1 to 1.0 molar ratios in order to determine the exact eutectic composition. The SQV-PIP system formed a eutectic at a composition of 0.6 and 0.40, respectively. Then, a solid-state characterization through DSC, powder X-ray diffraction (PXRD), including small-angle X-ray scattering (SAXS) measurements to explore the small-angle region in detail, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and a powder dissolution test were performed. The conventional PXRD analyses suggested that the eutectic mixture did not exhibit structural changes; however, the small-angle region explored through the SAXS instrument revealed a change in the crystal structure of one of their components. FT-IR spectra showed no molecular interaction in the solid state. Finally, the dissolution profile of SQV in the eutectic mixture was different from the dissolution of pure SQV. After 45 min, approximately 55% of the drug in the eutectic mixture was dissolved, while, for pure SQV, 42% dissolved within this time. Hence, this study concludes that the dissolution rate of SQV can be effectively improved through the approach of using PIP as a coformer. [ABSTRACT FROM AUTHOR]

Antiferroelectricity is a desirable property of liquid crystalline materials. Therefore, we synthesised and studied two new chiral rod-like mesogens with a molecular core based on two biphenyls connected via ester linkage, with the phenyl substituted by a fluorine atom. The studied mesogens are characterised by nuclear magnetic resonance spectroscopy and mass spectrometry analysis. They have methyl heptyl in the chiral chain and exhibit an antiferroelectric phase in a very broad temperature range. We investigated their mesomorphic properties and confirmed the phase identification by differential scanning calorimetry and broad-frequency dielectric spectroscopy measurements. Additionally, we compared the studied mesogens with previously synthesised analogous materials. Two mixtures were formulated using a base mixture and new mesogens. The helical pitch of the synthesised mesogens and formulated mixtures was estimated using the selective reflection method. [ABSTRACT FROM AUTHOR]

Functionalized porous carbons are central to various important applications such as energy storage and conversion. Here, a simple synthetic route to prepare oxygen‐rich carbon nitrides (CNOs) decorated with stable Ni and Fe‐nanosites is demonstrated. The CNOs are prepared via a salt templating method using ribose and adenine as precursors and CaCl2·2H2O as a template. The formation of supramolecular eutectic complexes between CaCl2·2H2O and ribose at relatively low temperatures facilitates the formation of a homogeneous starting mixture, promotes the condensation of ribose through the dehydrating effect of CaCl2·2H2O to covalent frameworks, and finally generates homogeneous CNOs. As a specific of the recipe, the condensation of the precursors at higher temperatures and the removal of water promotes the recrystallization of CaCl2 (T < Tm = 772 °C), which then acts as a hard porogen. Due to salt catalysis, CNOs with oxygen and nitrogen contents as high as 12 and 20 wt%, respectively, can be obtained, while heteroatom content stayed about unchanged even at higher temperatures of synthesis, pointing to the extraordinarily high stability of the materials. After decorating Ni and Fe‐nanosites onto the CNOs, the materials exhibit high activity and stability for electrochemical oxygen evolution reaction with an overpotential of 351 mV. [ABSTRACT FROM AUTHOR]

The major issue with active pharmaceutical ingredients (APIs) is their slow dissolution rate and solubility. This makes them less likely to get into the body and less bioavailable. About 40 % of the drugs already on the market and 90 % being made have APIs that do not dissolve well in water. To deal with this problem, authors have designed eutectic mixture (EMs) of different drugs (danazol, griseofulvin, mefenamic acid, tolfenamic acid and tadalafil) with zinc chloride; studied their interaction and thermodynamic parameters using Density Functional Theory (DFT) computation. DFT calculations confirm an increase in the dipole moment of their EMs in comparison of APIs alone which increases the solubility. The change in Gibbs free energy of formation of EMs in the gaseous phase shows their feasibility ans stability. [ABSTRACT FROM AUTHOR]

Abstract Functionalized porous carbons are central to various important applications such as energy storage and conversion. Here, a simple synthetic route to prepare oxygen‐rich carbon nitrides (CNOs) decorated with stable Ni and Fe‐nanosites is demonstrated. The CNOs are prepared via a salt templating method using ribose and adenine as precursors and CaCl2·2H2O as a template. The formation of supramolecular eutectic complexes between CaCl2·2H2O and ribose at relatively low temperatures facilitates the formation of a homogeneous starting mixture, promotes the condensation of ribose through the dehydrating effect of CaCl2·2H2O to covalent frameworks, and finally generates homogeneous CNOs. As a specific of the recipe, the condensation of the precursors at higher temperatures and the removal of water promotes the recrystallization of CaCl2 (T < Tm = 772 °C), which then acts as a hard porogen. Due to salt catalysis, CNOs with oxygen and nitrogen contents as high as 12 and 20 wt%, respectively, can be obtained, while heteroatom content stayed about unchanged even at higher temperatures of synthesis, pointing to the extraordinarily high stability of the materials. After decorating Ni and Fe‐nanosites onto the CNOs, the materials exhibit high activity and stability for electrochemical oxygen evolution reaction with an overpotential of 351 mV.

Interheteromolecular hyperconjugation is ubiquitous in organic systems, affecting bond length, dipole moments, conformations and so on, while its effect on (de)hydrogenation reactivity in a heterogeneous thermo‐catalytic system has rarely been explored. Herein, the N‐heterocycles containing a benzene ring and aliphatic chain [N‐ethylcarbazole (NEC) and N‐propylcarbazole (NPC)] were utilized to study the correlation between interheteromolecular hyperconjugation and catalytic (de)hydrogenation. Density functional theory calculations, variable‐temperature 1H nuclear magnetic resonance spectroscopy, and catalytic experiments showed that the presented hyperconjugation between NEC and NPC weakened the electron cloud density of aromatic rings and thus facilitated the reactivity with hydrogen featuring unpaired electrons. Therefore, an extremely low temperature of 80 °C was enough for the hydrogenation. Moreover, this interheteromolecular hyperconjugation was general in other N‐heterocycles (e. g. N‐methyindole and NPC) and was also effective to (de)deuterate as revealed by isotope experiments. This work expands the application of interheteromolecular hyperconjugation to heterogeneous thermocatalysis for reversible H2 storage. [ABSTRACT FROM AUTHOR]

A series of fatty acid binary eutectic mixtures were prepared by using capric acid, lauric acid, myristic acid, palmitic acid, and stearic acid (CA, LA, MA, PA, and SA) as raw materials. The phase diagrams of these fatty acid binary eutectic mixtures were drawn using the Schrader equation. The thermal properties and structure were determined using differential scanning calorimetry (DSC). The thermal stability was assessed using thermogravimetric analysis (TGA) and thermal cycling tests. DSC analysis results showed that the phase change temperature of these fatty acid binary eutectic mixtures is between 17.7 °C and 57.1 °C, and the phase change latent heat is between 145.2 J/g and 193.0 J/g. The results of TGA and thermal cycle tests showed that these fatty acid binary eutectic mixtures have good thermal stability and long-term cycle thermal reliability. These results indicated that these binary eutectic mixtures of fatty acids were suitable as thermal energy storage materials for low-temperature systems. [ABSTRACT FROM AUTHOR]

The dissolution rate of the anti-HIV drug saquinavir base (SQV), a poorly water-soluble and extremely low absolute bioavailability drug, was improved through a eutectic mixture formation approach. A screening based on a liquid-assisted grinding technique was performed using a 1:1 molar ratio of the drug and the coformers sodium saccharinate, theobromine, nicotinic acid, nicotinamide, vanillin, vanillic acid, and piperine (PIP), followed by differential scanning calorimetry (DSC). Given that SQV-PIP was the only resulting eutectic system from the screening, both the binary phase and the Tammann diagrams were adapted to this system using DSC data of mixtures prepared from 0.1 to 1.0 molar ratios in order to determine the exact eutectic composition. The SQV-PIP system formed a eutectic at a composition of 0.6 and 0.40, respectively. Then, a solid-state characterization through DSC, powder X-ray diffraction (PXRD), including small-angle X-ray scattering (SAXS) measurements to explore the small-angle region in detail, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and a powder dissolution test were performed. The conventional PXRD analyses suggested that the eutectic mixture did not exhibit structural changes; however, the small-angle region explored through the SAXS instrument revealed a change in the crystal structure of one of their components. FT-IR spectra showed no molecular interaction in the solid state. Finally, the dissolution profile of SQV in the eutectic mixture was different from the dissolution of pure SQV. After 45 min, approximately 55% of the drug in the eutectic mixture was dissolved, while, for pure SQV, 42% dissolved within this time. Hence, this study concludes that the dissolution rate of SQV can be effectively improved through the approach of using PIP as a coformer.

Nematic phase at room temperature with wide stability and high birefringence is particularly desirable for functional devices. Two thermotropic liquid crystals (tolane and the 4-pentyl-4-biphenylcarbonitrile nematic also known as 5CB) are mixed by varying the weight fraction (wt%) in order to investigate the phase sequences and their physical properties using differential scanning calorimetry (DSC), polarised optical microscopy (POM) and dielectric spectroscopy techniques. Phase coexistence was observed for a concentrations 20 ≤ C ≤ 60 wt% of tolane in 5CB and the phase diagram was established. In addition, the nematic-isotropic temperature TNI increases with increasing the concentration of tolane LCs. A eutectic mixture at room temperature with large nematic range and high birefringence is obtained for C = 10 wt%. The increase in the nematic range is due to an enhancement of the nematic order induced by the LCs. It is found that the electro optical parameters like the threshold voltage, the response time were relatively increased. This increment can be attributed to an increase in the viscoelastic properties of the mixture. [ABSTRACT FROM AUTHOR]

A series of fatty acid binary eutectic mixtures were prepared by using capric acid, lauric acid, myristic acid, palmitic acid, and stearic acid (CA, LA, MA, PA, and SA) as raw materials. The phase diagrams of these fatty acid binary eutectic mixtures were drawn using the Schrader equation. The thermal properties and structure were determined using differential scanning calorimetry (DSC). The thermal stability was assessed using thermogravimetric analysis (TGA) and thermal cycling tests. DSC analysis results showed that the phase change temperature of these fatty acid binary eutectic mixtures is between 17.7 °C and 57.1 °C, and the phase change latent heat is between 145.2 J/g and 193.0 J/g. The results of TGA and thermal cycle tests showed that these fatty acid binary eutectic mixtures have good thermal stability and long-term cycle thermal reliability. These results indicated that these binary eutectic mixtures of fatty acids were suitable as thermal energy storage materials for low-temperature systems.

During the last decades, many efforts have been devoted to the adaptation of sample preparation techniques and methods to the principles of Green Analytical Chemistry. Among them, this article review focusses on those aimed to green the solvents involved in sample treatment. Research in this field started in the late 1990s with the synthesis of room temperature ionic liquids, which were later replaced by the deep eutectic solvents (DESs). During the last years, a subclass of DESs, the so-called hydrophobic deep eutectic solvents (HDESs) have attracted attention. HDESs have contributed to circumventing some of the limitations of early-synthesised hydrophilic DESs regarding the cost of raw materials, the simplicity of synthesis, and the biocompatibility and, apparently, the biodegradability of the mixtures. In addition, these mixtures allowed the treatment of aqueous samples and the extraction of non-polar analytes. This article discusses fundamental aspects regarding the nomenclature used concerning HDESs, summarises the main physicochemical properties of these mixtures, and through discussion of key application studies, describes current progress in the use of these green solvents for the extraction of trace organic contaminants from a variety of matrices. Remaining gaps and possible lines of future development in this emerging, active and attractive research area are also identified and critically discussed. [Display omitted] • Current use of hydrophobic (deep) eutectic solvents for sample preparation reviewed. • Applications dealing with the determination of organic pollutants are discussed. • A critical overview of the several methodologies in use is provided. • Remaining issues and possible future developments are identified. [ABSTRACT FROM AUTHOR]

Complexity and heterogeneous nature of most diseases have posed greater challenges in the modern healthcare system. Fixed-dose combination can offer an ideal way to improve patient compliance and higher therapeutic efficacy. However, biopharmaceutical issues associated with the drug combinations remain unaddressed. Multidrug eutectics (MDE) have demonstrated significant promise in improving the biopharmaceutical attributes with synergistic therapeutic action. Eutectic mixtures are the multicomponent solid forms that possess lesser melting point than the individual components at a fixed composition. Non-covalent linking of drug combinations as MDE is an innovative strategy with enhanced solubility, dissolution, and mechanical and potential therapeutic efficacy. This review provides a comprehensive overview of the design of MDE, rational selection of drugs, characterization tools, and their therapeutic potential. Besides, the futuristic perspective where MDE could make a significant impact on combination therapy is briefly outlined. [ABSTRACT FROM AUTHOR]

This paper reports for the first time the possible formation of a novel room temperature therapeutic deep eutectic solvent (THEDES) of risperidone (RIS) with some fatty acids, namely capric acid (C10; CA), lauric acid (C12; LA), and myristic acid (C14; MA). All mixtures of RIS and MA yielded a solid or pasty-like solid and were readily discarded. Some of the prepared THEDESs from RIS and CA or LA have spontaneously transformed into a transparent liquid, without any precipitate at room temperature by simple physical mixing of the components. From the DSC thermograms, phase diagrams of the eutectic systems were constructed and the lowest obtained melting point for a RIS:CA mixture was 17°C at 40:60% w/w ratio. While 22°C was recorded as the lowest melting point for RIS:LA at a ratio of 30:70% w/w, solubility improvement of RIS was up to 70,000-fold compared with water. Freeze-drying microscopy provided valuable information regarding the phase change and transitions the drug undergoes as a function of temperature and it clarifies the interpretation of the DSC results and provides valuable evidence of drug crystals co-melting within the fatty acid base. The presence of natural fatty acid as one component of THEDES and the depression in the melting point significantly (P < 0.05) enhanced RIS skin permeation. Rheological studies showed a viscosity temperature dependency of the DES and well fitted to the Arrhenius equation. Application of the obtained THEDES on the shaved skin of rats revealed the absence of any irritation or edema effects. [ABSTRACT FROM AUTHOR]

Pain management is one of the most commonly faced problem for dentists while handling of pediatric patients. A positive dental attitude can be instilled in a child if pain is handled properly. In recent times, various advancements and research have been made in the field of local anesthesia. These techniques along with the conventional ones can be utilized for better handling of pain and to get better apprehension from patients. This review article is to discuss recent advancements in painless anesthetic techniques and to improve the quality of treatment regarding pain in pediatric dentistry. As management of pain is of paramount importance to instill a positive attitude about dentistry in children. [ABSTRACT FROM AUTHOR]

Summary: In the present work, we describe the chemical synthesis of 3‐HFAs as prominent derivatives of fatty acids and assess if they could be applied as phase change materials (PCM). In addition, 3‐HFAs were obtained by depolymerization of a bacterial biopolymeric material, polyhydroxyalkanoate. Thermal properties of 3‐hydoxyoctanoic, decanoic, and dodecanoic acids are reported for the first time. These materials showed the potential to be applied as PCM in temperature range from 33°C to 66°C. In order to expand the temperature range for application of 3‐HFAs as PCM, eutectic mass ratios of three kinds of binary mixtures of 3‐HFAs were calculated, and their properties were predicted using the Schröder‐van Laar equation. Thermal properties of these mixtures were validated by differential scanning calorimetry (DSC) analysis. These results showed that eutectics considerably expanded the scope of applications of 3‐HFAs as PCMs. 3‐HFAs originating from biotechnologically obtained polyhydroxyalkanoates also showed potential to be applied in development of PCMs. [ABSTRACT FROM AUTHOR]

Novel chiral three-ring (R) enantiomers were synthesised using optically active (R)-(−)-2-octanol. Properties, such as the sequence of phases, the transition temperatures and enthalpies, were tested by a polarising optical microscope and differential scanning calorimeter. An antiferroelectric smectic phase (SmCA*) with a direct transition from the antiferroelectric to the isotropic phase (SmCA*-Iso) was observed for three esters with an achiral C3F7CH2O(CH2)3O– terminal chain. Bi- and multicomponent mixtures with a broad temperature range of the antiferroelectric phase and good electro-optical properties were formulated. Helical pitch of pure esters and mixtures was measured by spectrophotometry method. [ABSTRACT FROM AUTHOR]

Crystal engineering approach was utilized for the development of different multicomponent solid forms of telmisartan (TEL) to improve its oral bioavailability. In this context, two cocrystals, gentisic acid (GA) and maleic acid (MA), while two eutectic mixtures, para-aminobenzoic acid (PABA) and adipic acid (AA), were successfully prepared and characterized by different analytical tools. Both the cocrystals exhibited characteristic heterosynthons, viz. OHacid⋯Narom and OHacid⋯O, to propagate new network. Structural features of coformers has been correlated with the outcomes of cocrystallization approach. Coformers having auxiliary functionality in addition to complementary functional groups have high propensity to generate cocrystals. However, multicomponent where auxiliary functionality is lacking, such combinations, is shown to form eutectic mixtures owing to strong homomeric interaction. Besides, the developed cocrystals and eutectic mixtures showed higher aqueous solubility (3–5.5-fold) and intrinsic dissolution rate (1–2.6-fold) over pure TEL. In vivo studies also revealed significant improvement in relative bioavailability (2–2.6-fold). The study also shed light on the implications of eutectic mixtures in mitigating the solubility issues of drugs which are often considered negative results of cocrystallization strategy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis and characterisation of new N -alkylisoquinolinium bromides. • Determined solid–liquid phase diagrams of isoquinolinium ILs with α,ω -alkanediols. • Discovery of supramolecular self-organisation phenomena leading to interesting co-crystalline IL/ α,ω -diol structures. • Designation and examination of eutectic mixtures as promising eutectic PCMs. • Conclusions drawn from the structure – property relationship: the effect of aliphatic chain length of IL and α,ω -diol. This research focuses on ionic liquids (ILs), specifically N -alkylisoquinolinium bromides with various chain lengths: octyl, decyl, dodecyl, and hexadecyl. The study covers the synthesis and thermophysical characterisation of these compounds, as well as crystal structure determination for all excluding N -decylisoquinolinium bromide ([i-QuinC 10 ][Br]). The obtained thermophysical parameters were compared with the literature data and also within the extended homologous series. The solid–liquid phase equilibria (SLE) in mixtures of ILs with certain α,ω -alkanediols (1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol) were investigated. As a result of SLE studies, eutectic mixtures capable of acting as eutectic phase-change materials - ePCMs - were determined. Additionally, a self-organization phenomenon was observed between specific pairs, leading to the formation of co-crystals (solid-complex phase). All binary mixtures with [i-QuinC 8 ][Br] formed a simple eutectic system, while in the case of [i-QuinC 10 ][Br], the formation of a non-congruent melting compound was observed in the systems with 1,8-octanediol and 1,10-decanediol. Among the systems with [i-QuinC 12 ][Br], congruent melting compounds were observed for mixtures with 1,8-octanediol, 1,10-decanediol and 1,12-dodecanediol, while a simple eutectic was recorded for 1,6-hexanediol. IL [i-QuinC 16 ][Br] co-crystalised only with 1,12-dodecanediol, while with other diols formed simple eutectic systems. Calorimetric analysis (DSC) and crystal structure determination (X-ray diffraction) were used to characterize the obtained supramolecular compounds. As a result, a series of ePCMs with melting points ranging from 295 K to 343 K are presented, with the {[i-QuinC 12 ][Br] + 1,10-decanediol} system showing the highest enthalpy of melting (173.5 J·g−1). The found features and correlations between structure and properties imply the necessity for additional investigation, indicating the potential for a new generation of compounds with customizable physicochemical properties. [ABSTRACT FROM AUTHOR]

• Eutectic mixtures of the APIs with the amino acids were designed. • Physiochemical properties in default and water were studied. • Solubility of designed eutectic mixtures of APIs have been determined and discussed. • Solubility of the designed eutectic mixtures is better than the APIs were found. Solubility is a major concern for many active pharmaceutical ingredients (APIs) and drugs. Owing to their better solubility, biodegradability and low toxicity of APIs and drugs, eutectic mixtures are emerging as the system to enhance their solubility with no loss of biological activity. In the present work, authors have taken camizestrant, deucravacitinib, and iclepertin as the active pharmaceutical ingredients (API) because they have poor solubility in water. Authors have designed eutectic mixtures (EMs) of the selected APIs with the amino acids (aspartic acid, lysine, phenylalanine, and proline) and studied for their physiochemical properties in default and water using density functional theory calculations, performed by Gaussian. The solubility of the APIs, amino acids and the designed eutectic mixtures of APIs have been determined and discussed using the dipole moment. The results showed that the solubility of the designed eutectic mixtures have better aqueous solubility than the APIs alone. Further, molecular dynamics (MD) simulations were done for APIs and EMs to study their stability and interactions. [ABSTRACT FROM AUTHOR]

• A rigorous database of physico-chemical properties of eutectic solvent mixtures with various water contents. • Many solvent mixtures thought to be 'deep eutectic solvents' do not deviate from ideal thermal behaviour. • Water has a significant impact on all physico-chemical and thermal properties. Deep eutectic solvents are of significant interest to numerous applications including cryopreservation, chemical synthesis, lubrication, energy storage, catalysis, and self-assembly. However, to date there have been few rigorous and systematic studies of the physico-chemical and thermal properties of these solvents. This means that conclusive structure-function relationships are difficult to define within the context of the current literature. Here, we present the viscosity, refractive index, density, surface tension, and thermal behaviour of mixtures of either glycerol or ethylene glycol with choline chloride, betaine, or L-proline, as neat fluids and in the presence of water. We demonstrate that changing the ratio of hydrogen bond donor to hydrogen bond acceptor has only a small effect on the physico-chemical properties, while the addition of even small quantities of water has a significant effect. Despite rigorous studies, we demonstrate that determining the eutectic point of these mixtures is not straight-forward and that the definition of a 'deep' eutectic solvent may need to be reviewed in the frame of ideal mixing theory. [ABSTRACT FROM AUTHOR]

The applications of eutectic systems, including deep eutectic solvents (DESs), in diverse sectors have drawn significant interest from researchers, academicians, engineers, medical scientists, and pharmacists. Eutecticity increases drug dissolution, improves drug penetration, and acts as a synthesis route for drug carriers. To date, DESs have been extensively explored as potential drug delivery systems on account of their unique properties such as tunability and chemical and thermal stability. This review discusses two major topics: first, the application of eutectic mixtures (before and after the introduction of DES) in the field of drug delivery systems, and second, the most promising examples of DES pharmaceutical activity. It also considers future prospects in the medical and biotechnological fields. In addition to the application of DESs in drug delivery systems, they show greatly promising pharmaceutical activities, including anti-fungal, anti-bacterial, anti-viral, and anti-cancer activities. Eutecticity is a valid strategy for overcoming many obstacles inherently associated with either introducing new drugs or enhancing drug delivery systems. [ABSTRACT FROM AUTHOR]

A stricter definition of a deep eutectic solvent (DES) is urgent, so that it may become a sound basis for further developments in this field. This communication aims at contributing to deepening the understanding of eutectic and deep eutectic mixtures concerning their definition, thermodynamic nature and modelling. The glut of literature on DES applications should be followed by a similar effort to address the fundamental questions on their nature. This hopefully would contribute to correct some widespread misconceptions, and help to establish a stringent definition of what a DES is. DES are eutectic mixtures for which the eutectic point temperature should be lower to that of an ideal liquid mixture. To identify and characterize them, their phase diagrams should be known, in order to compare the real temperature depression to that predicted if ideality is assumed, and to define composition ranges for which they are in the liquid state at operating temperatures. It is also shown that hydrogen bonding between the DES components should not be used to define or characterize a DES, since this would describe many ideal mixtures. The future of deep eutectic solvents is quite promising, and we expect that this work will contribute to the efficient design and selection of the best DES for a given application, and to model properties and phase equilibria without which the process design is impractical. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the temperature-dependent relaxation dynamics in the glassy and supercooled liquid state of dipolar and ionic eutectic mixtures made of two anesthetic agents (lidocaine and prilocaine) and their hydrochloride salts, respectively. In addition to eutectic phases containing 1:1 and 4:1 mol/mol of LD/PRL and LD-HCl/PRL-HCl, respectively, the relaxation properties of non-eutectic compositions and parent compounds are also studied. We found that electrostatic long-range forces determine strongly the dielectric and mechanical response of eutectic material. As a result of Coulomb interactions between ion pairs, an additional β-relaxation mode was found in the dielectric spectra of glassy LD-HCl/PRL-HCl mixtures. On the other hand, the studies of relaxation dynamics of ionic and non-ionic mixtures at T > T g revealed a continuous decrease of both fragility m P and the length scale of dynamic heterogeneity N α B (T g), with simultaneous growth of T g , when the electrostatics forces appear. At the same time, we found the charge transport being decoupled from structural dynamics in all studied ionic binary mixtures that is due to the fast proton hopping. However, the efficiency of proton transport is dropping down with an increase of T g. Unlabelled Image [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Two of the designed novel solvents deviate from ideal eutectic phase behavior. • Trioctylphosphine oxide-based eutectic mixtures only extract undissociated acids. • Eutectic mixtures show distribution coefficients: acetic < propionic < butyric acid. • Acid distribution coefficients increase with mole fraction trioctylphosphine oxide. Abstract Organic waste streams can be converted into volatile fatty acids (VFAs) via fermentation. VFAs can be used as intermediates in the synthesis of added-value chemicals. In this work, hydrophobic eutectic mixtures were designed for the liquid-liquid extraction of VFAs from dilute aqueous solutions. The eutectic behaviour was screened for over 100 combinations of 16 hydrophobic components that were selected based on a set of predetermined criteria. Mixtures of dihexylthiourea and trioctylphosphine oxide (TOPO) showed the best extraction performance and were stable over a wide pH range. The extraction efficiency increased with increasing hydrophobicity of the VFAs, and only undissociated acids were extracted. Upon increasing the TOPO content of the eutectic mixture, the extraction performance could be improved, confirming the tuneable nature of eutectic solvents. However, the extraction performance was less than that for solutions of TOPO in hydrophobic solvents, even though mole fractions of TOPO were higher in the eutectic mixtures. It was hypothesized that the intermolecular VFA–TOPO interactions required for extraction are suppressed by the inter-component interactions in the eutectic mixture. The inter-component interactions are responsible for the negative deviation from ideality of the melting temperature depressions that extend the liquid window of the mixtures towards the extraction temperature. Hence, the design of novel hydrophobic extractants based on eutectic mixtures was demonstrated. Their performance might be improved by selecting counterparts that interfere less with the interactions required for VFA extraction. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DESs) consist of a mixture of two or more solid components, which gives rise to a lower melting point compared to the starting materials. Until recently only hydrophilic DESs were available, and despite their revolutionary role in the alternative‐solvents field, important issues in chemistry, and chemical engineering (such as water‐related problems and the replacement of toxic volatile organic compounds) could not be tackled. Hydrophobic (deep)—here in parenthesis due to the different depths of the eutectic melting points—eutectic solvents are a subclass of DESs where both components are hydrophobic. The low toxicity, high biodegradability, and straightforward preparation without further purification steps of naturally occurring low‐cost compounds are among the key advantages. Although research on hydrophobic DESs is scarce (the first report was only published in 2015), some interesting features and applications have been reported and deserve to be evaluated and comparisons established. This Minireview is divided into two parts: The first part provides a brief general introduction to DESs and the second part discusses the nomenclature using solid–liquid phase diagram analysis, chemical stability, thermophysical properties comparison, and finally the most important emerging fields of application. [ABSTRACT FROM AUTHOR]

Abstract Deep eutectic solvents (DESs) have been widely recognized as ionic liquids (ILs) analogues due to their low production cost and superior favorable properties over conventional ILs. Studying the physical properties of these solvents will contribute to design processes involving DESs. In this study, five DESs have been successfully prepared using ethylene glycol (EG) as hydrogen bond donor (HBD) with N , N ‑diethylethanolammonium chloride (DAC), benzyltriphenylphosphonium chloride (BTPC), choline chloride (ChCl), methyltriphenylphosphonium bromide (MTPB) and tetra‑ n ‑butylammonium bromide (TBAB) as salts. The freezing point of each of the five studied DESs was measured using Differential Scanning Calorimetry (DSC) and the DES functional groups were identified using the Fourier transform infrared (FTIR) spectroscopy. Moreover, the viscosity, density, electrical conductivity and surface tension were measured at a temperature range of 293.15–353.15 K and they were highly affected by the variation of the temperature. It is worth mentioning that the studied DESs showed many physical characteristics similar to that of ILs, which boost their possibilities to be employed in interdisciplinary domains. Graphical abstract Unlabelled Image Highlights • Ethylene glycol based deep eutectic solvents (DESs) were prepared from different salts. • The ratios of salt to HBD were selected based on homogeneity and stability of the DES. • The studied DESs showed physical properties similar to that of ionic liquids. • FTIR analysis depicted the existence of new functional groups in DES structure. [ABSTRACT FROM AUTHOR]

Eutectic systems offer a wide range of new (green) designer solvents for diverse applications. However, due to the large pool of possible compounds, selecting compounds that form eutectic systems is not straightforward. In this study, a simple approach for preselecting possible candidates from a pool of substances sharing the same chemical functionality was presented. First, the melting entropy of single compounds was correlated with their molecular structure to calculate their melting enthalpy. Subsequently, the eutectic temperature of the screened binary systems was qualitatively predicted, and the systems were ordered according to the depth of the eutectic temperature. The approach was demonstrated for six hydrophobic eutectic systems composed of L-menthol and monocarboxylic acids with linear and cyclic structures. It was found that the melting entropy of compounds sharing the same functionality could be well correlated with their molecular structures. As a result, when the two acids had a similar melting temperature, the melting enthalpy of a rigid acid was found to be lower than that of a flexible acid. It was demonstrated that compounds with more rigid molecular structures could form deeper eutectics. The proposed approach could decrease the experimental efforts required to design deep eutectic solvents, particularly when the melting enthalpy of pure components is not available.

The present research work highlights the development of multicomponent solid form of the antihypertensive drug irbesartan (IRB) to improve its biopharmaceutical attributes. Mechanochemical synthesis of a new solid form of IRB with coformers having antioxidant properties (syringic acid, nicotinic acid, and ascorbic acid) resulted into three eutectic mixtures (EMs). Formation of eutectic was ascertained by differential scanning calorimetry whereas exact stoichiometry (50/50% w/w) was established by phase diagram and Tamman’s triangle. The strong homomeric interaction between individual components and steric hindrances is responsible for the eutectic formation. EMs exhibited superior apparent solubility (five- to nine fold) and significant enhancement in intrinsic dissolution rate (two- to three fold) as compared to the plain drug. In vivo pharmacokinetic and in vivo pharmacodynamic studies revealed a significant improvement in the biopharmaceutical performance of EMs. Marked protection against oxidative stress was observed in EMs over plain drug by controlling the level/activity of plasma H2O2 and antioxidant enzymes (superoxide dismutase and catalase) in the kidney matrix of dexamethasone (Dexa)-induced hypertensive rats. Thus, these solid forms of IRB can serve as viable multicomponent forms to be translated into product development for better therapeutic efficacy in the management of hypertension. [ABSTRACT FROM AUTHOR]

The transesterification of palm oil and mixed dimethyl/diethyl carbonate (DMC/DEC) was investigated to produce glycerol-free biodiesel with improved cold flow performance. The potassium hydroxide (KOH) was used as the cheap heterogeneous catalyst. The biodiesel yield could reach 90.8% and the molar ratio of FAMEs/FAEEs was fixed as 2:1 over the following optimal reaction conditions: Molar ratio of DMC/DEC was 1:1, molar ratio of mixed DMC/DEC and oil was 14:1, KOH amount was 15 wt% (based on the oil), reaction temperature was 100 °C and reaction time was 20 h. The biodiesel had a cold filter plugging point of 3 °C and a solidifying point of −2 °C, which met the cold flow requirements of commercial 0# diesel in China. Finally, the cold flow properties of biodiesel/diesel blends were carefully characterized. Interestingly, due the formation of eutectic mixtures between n -alkanes in diesel and saturated esters in biodiesel, the cold flow performance of diesel could be significantly improved by adding no more than 30 v% of biodiesel. [ABSTRACT FROM AUTHOR]

Abstract: This study focuses on the preparation, thermophysical properties, and corrosion analysis of a stable capric acid/cetyl alcohol eutectic phase‐change material (PCM) for application in the thermal comfort of buildings. Differential scanning calorimetry is used to investigate the thermal properties of the prepared eutectic PCM, and the results show that the eutectic composition of 70 % capric acid and 30 % cetyl alcohol was suitable for low‐temperature thermal energy storage as it had melting and freezing temperatures of 22.89 and 11.97 °C, respectively. The latent heats of melting and freezing of the eutectic PCM are 144.92 and 145.85 J g−1, respectively. The changes in the melting point and latent heat of the eutectic mixtures over continuous charging/discharging cycles are presented. The accelerated thermal cycling test and FTIR spectra show that the prepared eutectic PCM has a good thermal stability over 1000 thermal cycles. Moreover, corrosion compatibility tests for Cu, Al, and stainless steel 316 samples with the prepared eutectic PCM are discussed, and recommendations for the use of the PCM in the operational environment are presented. [ABSTRACT FROM AUTHOR]

Lovastatin (LOV) is a drug used to treat hypercholesterolemia. Recent studies have identified its antioxidant effects and potential use in the treatment of some types of cancer. However, the low bioavailability related to its poor water solubility limits its use in solid oral dosage forms. Therefore, to improve the solubility of LOV three eutectic systems of LOV with the carboxylic acids benzoic (BEN), salicylic (SAL) and cinnamic (CIN) were obtained. Both binary phase and Tammann diagrams were constructed using differential scanning calorimetry (DSC) data of mixtures prepared from 0.1 to 1.0 molar ratios. Binary mixtures and eutectics were prepared by liquid-assisted grinding. The eutectics were further characterized by DSC and powder X-ray diffraction (PXRD), Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The LOV-BEN, LOV-SAL and LOV-CIN system formed a eutectic at an LOV mole fraction of 0.19, 0.60 and 0.14, respectively. The systems exhibited improvements in LOV solubility, becoming more soluble by five-fold in the LOV-SAL system and approximately four-fold in the other two systems. Considering that the solubility enhancements and the carboxylic acids used are generally recognized as safe by the U.S. Food and Drug Administration (FDA), the LOV eutectic systems are promising materials to be used in a solubility enhancement strategy for pharmaceutical product formulation.

The ability to dissolve cellulose, by using mixtures of ionic liquids, has been studied and compared with results obtained for the corresponding single ionic liquids. The ionic liquid mixtures tested were a 3:7 mol/mol mixture of 1-ethyl-3-methylimidazolium chloride ([C 2 mim]Cl) and 1-ethyl-3-methylimidazolium acetate ([C 2 mim][OAc]), and the eutectic mixture (i.e., a 5.1:4.9 mol/mol ratio) of [C 2 mim]Cl and 1-butyl-3-methylimidazolium chloride (C 4 mim]Cl). The amount of dissolved cellulose was investigated at three different temperatures (323, 348, and 373 K) for each system. The greatest amount of dissolved cellulose was obtained for the [C 2 mim]Cl + [C 2 mim][OAc] mixture, at 373 K, and it was 40 g per 100 g of solvent. Moreover, attempts were made to lower the viscosity of the resulting systems and improve the dissolution capacity by addition of dimethylsulfoxide (DMSO) as co-solvent. Results showed that addition of DMSO at 50 mol% allows the dissolution of even greater amounts of cellulose (up to 43 g per 100 g of solvent). To the best of our knowledge, this is the largest ever reported amount of dissolved cellulose in ionic liquid media. Additionally, physical properties (density, surface tension, and viscosity) of the investigated ionic liquid mixtures were determined and compared with the values of the corresponding parent salts. The dissolved cellulose could be easily reconstituted from its solution in ionic liquid mixtures by addition of water. The regenerated cellulose was characterized by powder X-ray diffraction (pXRD), thermogravimetric analysis (TGA), and optical microscopy. The analyses confirmed the conversion of the crystal structure of cellulose from cellulose I to cellulose II during the dissolution and regeneration process. [ABSTRACT FROM AUTHOR]

The field of industrial biotechnology is rapidly growing. This includes the use of biosynthesis of the fragrance-row materials in chemical industry, food industry, cosmetical and pharmaceutical industry. The production of 2-phenylethanol (PEA), which is an important flavor and fragrance compound, with a rose-like odor has been significantly increased last decade. The ionic liquids (ILs) and binary eutectic mixtures (EM) are proposed as an entrainers for the extraction of PEA in a biphasic biosynthesis. ILs and DES reveal many unique properties which make them very interesting for applications in modern ‘green’ technologies. In this work we present new experimental results on (solid, or liquid + liquid) phase equilibrium (SLE/LLE) measurements of twelve binary systems composed of pyrrolidinium-based ILs (namely: 1-butyl-1-methylpyrrolidinium chloride, [BMPYR][Cl] and 1-butyl-1-methylpyrrolidinium bis{(trifluoromethyl)sulfonyl}imide [BMPYR][NTf 2 ] as well as 1-hexyl-1-methylpyrrolidinium chloride, [HMPYR][Cl] and 1-hexyl-1-methylpyrrolidinium bis{(trifluoromethyl)sulfonyl}imide [HMPYR][NTf 2 ] with alcohols (1-decanol, 2-methyl-1-butanol, 2-methyl-2-butanol) and oleic acid. Additionally, three ternary LLE mixtures are presented {IL, or EM + PEA + water} at T = 308.15 K and ambient pressure. The data reveals that [HMPYR][NTf 2 ] ionic liquid is more attractive than [BMPYR][NTf 2 ] and that EMs ([BMPYR][NTf 2 ] + 2-methyl-2-butanol) and ([HMPYR][NTf 2 ] + 2-methyl-2-butanol) present worst selectivities and solute distribution ratios than those observed for pure ILs. However, they may be assumed as an alternative, less cost solvents for the separation of PEA from the water phase using liquid-liquid extraction at ambient conditions. [ABSTRACT FROM AUTHOR]

Low-density lipoproteins (LDLs) are a class of nanocarriers for the targeted delivery of therapeutics into aberrant cells that overexpress the LDL receptor. A facile procedure is used for reconstituting the hydrophobic core of LDLs with a binary fatty acid mixture. Facilitated by the tumor targeting capability of the apolipoprotein, the reconstituted, drug-loaded LDLs can effectively target cancer cells that overexpress the LDL receptor while showing minor adverse impact on normal fibroblasts. According to a hypothesized mechanism, the reconstituted LDLs can also enable metabolism-triggered drug release while preventing the payloads from lysosomal degradation. This study demonstrates that LDLs reconstructed with fatty acids hold great promise to serve as effective and versatile nanocarriers for targeted cancer therapy. [ABSTRACT FROM AUTHOR]

Are deep eutectic solvents (DESs) a promising alternative to conventional solvents? Perhaps, but their development is hindered by a plethora of misconceptions. These are carefully analyzed here, beginning with the very meaning of DESs, which has strayed far beyond its original scope of eutectic mixtures of Lewis or Brønsted acids and bases. Instead, a definition that is grounded on thermodynamic principles and distinguishes between eutectic and deep eutectic is encouraged, and the types of precursors that can be used to prepare DESs are reviewed. Landmark works surrounding the sustainability, stability, toxicity, and biodegradability of these solvents are also discussed, revealing piling evidence that numerous DESs reported thus far, particularly those that are choline based, lack sufficient sustainability-related traits to be considered green solvents. Finally, emerging DES applications are reviewed, emphasizing their most remarkable feature: the ability to liquefy a solid compound with a target property, allowing its use as a liquid solvent.

Proton conducting polymer electrolytes employed in many electrochemical pseudocapacitors are typically based on aqueous systems, which limit the operating potential and temperature range of these energy storage devices. In this study, we developed non-aqueous polymer electrolytes based on protic ionic liquids (PIL). We relied on cationic substitution to obtain proton conducting yet environmentally benign non-fluorinated ionic liquids. By developing binary systems of PILs with different cations, eutectic compositions of PILs with drastically lowered melting points were demonstrated. Through thermal analyses of these binary systems, phase diagrams were constructed which allowed us to obtain eutectic binary PIL mixtures exhibiting a liquidus range from − 70 °C to 150 °C. These eutectic PIL mixtures were incorporated into polymer systems to develop non-aqueous thin film proton-conducting polymer electrolytes for solid pseudocapacitors. The proton conductivity of the eutectic ionic liquids was observed in the polymer electrolyte systems and promoted pseudocapacitive behavior in solid and liquid capacitor cells. [ABSTRACT FROM AUTHOR]

Several abundant agri-food wastes, including lemon peels, olive leaves, onion solid wastes, red grape pomace, spent filter coffee and wheat bran, were used to test the efficiency of some novel glycerol-based natural eutectic mixtures to extract polyphenolic compounds. Extractions were performed under specified ultrasonication conditions and the eutectic mixtures, tested as 90 % (v/v) aqueous solutions, were glycerol:choline chloride, glycerol:sodium acetate and glycerol:sodium-potassium tartrate:water, with corresponding molar ratios of 3:1, 3:1 and 5:1:4. The latter two mixtures are reported for the first time. Water and 60 % (v/v) aqueous ethanol were also used as control solvents. The results obtained evidenced that glycerol:choline chloride exhibited high efficiency, which was comparable or even surpassed that of aqueous ethanol, but in some instances the same was observed for glycerol:sodium acetate too. In general, glycerol:sodium-potassium tartrate:water displayed lower efficiency in extracting polyphenols. The data also suggested that extracts with high polyphenol concentration may also possess higher antiradical activity and reducing power. The findings of this study were interpreted on the ground of assumptions regarding the polarity of the eutectic mixtures tested. [ABSTRACT FROM AUTHOR]

Sugar alcohols (SA) are attractive phase change materials for long-term thermal energy storage (TES) applications at low-to-medium temperatures, as i.e. solar seasonal energy storage. Most of them undergo severe undercooling, thus allowing energy storage at temperatures far below the melting point with thermal losses reduction. Besides, some of them could provide very high volumetric energy density at affordable cost. However, sugar alcohols with high latent heat of fusion often exhibit melting temperatures above 100 °C. The objective of this work was to found out new sugar alcohol eutectic mixtures that display lower temperatures without significant reduction of the latent heat. A comprehensive analysis of SA relevant properties for TES has been carried out in order to select the most appropriate single SA for mixtures analysis. Sixteen SA-based binary systems have been investigated. Their corresponding phase diagrams have been experimentally and theoretically established. Four eutectic mixtures with potential for long-term TES at temperature around 80 °C have been identified. They are: 1) adonitol-erythritol at 30 mol% of erythritol, with melting temperature of 87 °C and latent heat of fusion of 254 J/g; 2) arabitol-erythritol at 40 mol% of erythritol, with melting temperature of 86 °C and latent heat of fusion of 225 J/g; 3) xylitol-erythritol at 36 mol% of erythritol, with melting temperature of 82 °C and latent heat of fusion of 270 J/g; and 4) arabitol-xylitol at 56 mol% of xylitol, with melting temperature of 77 °C and latent heat of fusion of 243 J/g. [ABSTRACT FROM AUTHOR]