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Budesonide (BDS) a steroid-based anti-inflammatory drug widely prescribed for various diseases, has a low aqueous solubility. In this study, we investigated cosolvency approach to study the thermodynamic specifications related to the solubility of BDS at the temperature range of 293.2–313.2 K in (1-propanol + water) mixtures applying the shaking flask method. The predictive power of different mathematical models for experimental data in the cosolvency systems was evaluated. For this purpose, the linear and nonlinear mathematical equations such as van't Hoff model (as a linear model), Buchowski-Ksiazczak equation (as a non-linear), CNIBS/R–K and MRS models (as a linear model for solvent composition at an isothermal condition), modified Wilson model (as a non-linear model for isothermal condition), the Jouyban-Acree model (as a model that considers temperature and solvent composition), and Jouyban-Acree-van't Hoff model (as a model with no further input data) were studied. Also, the Williams-Amidon excess Gibbs energy model was investigated. In addition, the related apparent thermodynamics of the BDS dissolution process in the desired temperature such as Gibbs free energy, enthalpy, and entropy, were computed by the corresponding equations. Moreover, based on the inverse Kirkwood-Buff integrals, it is demonstrated that BDS is preferentially solvated by water in water-rich mixtures. The accuracy of the fitness was evaluated with mean relative deviations (MRDs%) for back-calculated molar BDS solubility data. The result showed that the maximum solubility of BDS was obtained at 0.7 mass fraction of 1-propanol at all temperatures. Thermodynamic studies demonstrated that BDS dissolution procedures were obtained as endothermic and entropy-driven in almost all cases. The overall MRDs% values for the back-computed BDS solubility in the aqueous mixture of 1-propanol based on van't Hoff model, Buchowski-Ksiazczak equation, CNIBS/R–K model, modified Wilson model, Jouyban-Acree model, Jouyban-Acree-van't Hoff model, MRS model, and Williams-Amidon excess Gibbs energy model were found 1.93%, 1.80%, 11.68%, 33.32%, 12.30%, 9.24%, 10.70%, and 6.57%, respectively. Highlights: Study of BDS solubility profile in 1-propanol + water mixtures at 293.2 -313.2 K Prediction solubility with two Jouyban-Acree models: Jouyban-Acree equation and Jouyban-Acree-van't Hoff model Representation of BDS solubility data with some linear and nonlinear cosolvency models Utilize the van't Hoff and Gibbs equations to compute thermodynamic parameters [ABSTRACT FROM AUTHOR]

Background: Morphine serves as a foundation for creating other opioid derivatives, such as hydro/oxymorphine and heroin, which possess enhanced pain-relieving properties but are also prone to addiction and abuse. In cases of morphine overdose, it not only affects multiple immune functions but can also cause severe health complications. Given these concerns and the widespread use of morphine, it is crucial to develop efficient, uncomplicated, and precise methods for accurately detecting morphine in various biological and pharmaceutical samples. Results: In this investigation, a novel gold nanoparticle (AuNPs)-based double network hydrogel (DNH) nanoprobe has been fabricated for sensitive quantification of morphine in exhaled breath condensate samples. For that, gelatin/agarose DNH was fabricated through a one-step heating-cooling method in the presence of AuNPs, providing not only chemical stability but also prevent the AuNPs aggregation during synthesis process. In this method, the absorbance intensity of the nanoprobe gradually decreased with increasing morphine concentration due to the interaction morphine with AuNPs surface plasmon. The aggregation of AuNPs by addition of morphine was verified by UV-Vis spectrophotometry. The sensor displayed high sensitivity with detection limit of 0.006 µg.mL-1 in the linear range from 0.01 to 1.0 µg.mL-1. A reliable performance was attained for the spectrophotometric method for determination of morphine in the real samples. Significance: This article has reported a new advanced optical scaffold based on double network polymeric hybrid hydrogel for the determination of morphine. This is first report of using such composite for determination of opioids in exhaled breath condensate samples. [ABSTRACT FROM AUTHOR]

This study investigates the solubility behavior of Naproxen (NAP) in binary solvent mixtures of 1-propanol (1-PrOH) and 2-propanol (2-PrOH) with ethylene glycol (EG) across a range of temperatures. The solubility of NAP was experimentally determined at five different temperatures (293.15 to 313.15 K), and the data were correlated using various thermodynamic models, including the van't Hoff, Jouyban-Acree, modified Wilson, mixture response surface, Jouyban-Acree-van't Hoff. The results demonstrated that NAP's solubility increases with temperature in both solvent systems. Notably, NAP exhibited higher solubility in mixtures with 1-PrOH compared to 2-PrOH, despite the lower polarity of 2-PrOH. This unexpected trend is attributed to the distinct molecular interactions, including hydrogen bonding, influenced by the structural differences between 1-PrOH and 2-PrOH. The X-ray diffraction analysis confirmed that no polymorphic transformation occurred in NAP during dissolution, maintaining its crystalline structure. The solubility data were well-correlated by the applied models, with overall MRDs% (mean relative deviation percentage) below 6.1. [ABSTRACT FROM AUTHOR]

In this study, a novel fluorescence nanoprobe based on Materials of Institute Lavoisier (MIL-101) metal-organic frameworks embedding into the agarose hydrogel is fabricated using a hydrothermal technique. It uses for sensitive quantification of deferiprone in exhaled breath condensate (EBC) samples. The morphology and characterization of MIL-101/agarose nanocomposite hydrogel is studied by transmission electron microscopy, dynamic light scattering instrument, powder X-ray diffraction analysis, and Fourier transform infrared spectroscopy. The probe shows a reasonable fluorescence intensity quenching in the presence of deferiprone due to the interactions between iron centers in MIL-101 (Fe) and deferiprone, which likely form non-fluorescent complexes. The proposed nanoprobe demonstrates a linear calibration curve from 0.005 to 1.5 µg mL− 1 with a detection limit of 0.003 µg mL− 1. The intra- and inter-day precision of the reported method are 0.3% and 0.4% (n = 5, deferiprone concentration = 1.0 µg mL− 1), respectively. This method demonstrates high sensitivity and specificity towards deferiprone in the EBC samples and also presents a sensing platform with simplicity, convenience, fast implementation, and cost-effective in medical monitoring. [ABSTRACT FROM AUTHOR]

The equilibrium solubility of sulfadiazine (SD, 3) in several {acetonitrile (MeCN) + ethanol (EtOH)} mixtures at nine temperatures from T/K = (278.15 K to 318.15) has been determined by following the shake flask method. SD solubility increased with temperature-arising as well as with the MeCN proportion-increasing in the mixtures. Thus, x3 increased from 7.74 × 10−5 in neat EtOH to 6.20 × 10−4 in neat MeCN at T/K = 298.15. SD solubility was adequately correlated with a second-order multivariate equation as function of both mixtures composition and temperature. Moreover, two models including the Jouyban–Acree and Jouyban–Acree–van't Hoff models were applied to mathematical SD solubility data modeling in solvent mixtures. The accuracy of each model is investigated by the mean relative deviations (MRD%) of the back-calculated solubility. A full predictive model was provided by training the Jouyban–Acree–van't Hoff model with only seven experimental solubility data which provided excellent predictions with the MRD% of 3.7 %. All used models show a low MRD% values (< 4.0 %) for the calculated data indicating a good correlation of SD solubility data with the given mathematical models. By means of the van't Hoff and Gibbs equations, the apparent thermodynamic quantities relative to SD dissolution and mixing processes, namely Gibbs energies, enthalpies, and entropies, were calculated and reported. Apparent dissolution quantities of SD were positive in all cases indicating endothermic and entropy-driven behaviors. A non-linear enthalpy–entropy relationship was observed for SD in the plot of SD dissolution enthalpy vs. Gibbs energy. Observed trend exhibits negative slope in the composition from neat EtOH to the mixture of 0.05 in mass fraction of MeCN indicating entropy-driving mechanism for this SD transfer process. Moreover, variant but positive slopes were found in the composition interval of 0.05 < w1 < 1.00 indicating enthalpy-driving mechanism for these SD transfer processes. Furthermore, the preferential solvation of SD by MeCN or EtOH was analyzed by using the inverse Kirkwood–Buff integrals. Thus, SD is preferentially solvated by EtOH molecules in EtOH-rich mixtures but preferentially solvated by MeCN in MeCN-rich mixtures. In this way, this research expands the literature investigations about the solubility of SD in some non-aqueous cosolvent mixtures conformed by MeCN and other alcohols. [ABSTRACT FROM AUTHOR]

In this research, the solubility of amlodipine besylate was studied in the propylene glycol + ethanol mixtures at different temperatures (293.2–313.2 K). The study showed that the solubility increases with an increase in propylene glycol concentration, reaching its highest point at w1 = 0.8. Additionally, the solubility values have a positive correlation with temperature, which is typical for the solid solutes. The experimental solubility data were correlated with some well known cosolvency models and the accuracy of these models was investigated with the mean relative deviations (MRDs%) of the back-calculated data. MRDs were 1.2% for the van't Hoff model, 4.3 and 4.6% for the Jouyban–Acree and Jouyban–Acree–van't Hoff equations, 1.4% for the MRS model and 2.1% for the modified Wilson model. The apparent thermodynamic parameters (standard state Gibbs energy, enthalpy, and entropy) of dissolution of ADB in the non-aqueous saturated mixtures were also calculated with the van't Hoff and Gibbs equations at Thm = 303.0 K. [ABSTRACT FROM AUTHOR]

The present research proposed the use of silver nanoprism in a fluorescent system for phenytoin determination in exhaled breath condensate samples. The fluorescence emission of luminol was quenched by energy transfer to silver nanoprism and then the phenytoin addition induced silver nanoprism aggregation, inhibited the fluorescence quenching of luminol, and resulted in recovery of the fluorescence intensity proportionally with phenytoin concentration. The experimental parameters were optimized using a one-at-a time method, and the method was partially validated according to FDA guideline. The validated method had a good analytical performance to detect phenytoin in the range of 0.01 to 2.0 µg.mL−1, with a detection limit of 0.005 µg.mL−1. [ABSTRACT FROM AUTHOR]

This study aimed to measure both the solubility and thermodynamics of salicylic acid in binary solvent mixtures of (2-propanol + ethylene glycol) and (2-propanol + propylene glycol) at different temperatures in the range of 293.2–313.2 K. The experimental solubility data were analyzed using various linear and nonlinear cosolvency models, such as the van'tt Hoff, Jouyban-Acree, Jouyban-Acree-van'tt Hoff, mixture response surface and modified Wilson models and to evaluate the models, the mean relative deviations of the back-calculated solubility data were compared with experimental values. Through this analysis, the apparent thermodynamic parameters, including Gibbs energy, enthalpy, and entropy were calculated using the van'tt Hoff and Gibbs equations for this system. Additionally, the density values for salicylic acid saturated mixtures were also measured and represent mathematically using the Jouyban-Acree model. [ABSTRACT FROM AUTHOR]

This work focuses on physicochemical features of the choline chloride/propylene glycol deep eutectic solvent (DES) + water mixtures by determining their density values in mono- and mixed- states over various temperatures in the range of 293.15–318.15 K. The density data obtained from measurements were utilized for the computation of various quantities such as excess molar volumes, molar volume, apparent molar volume, limiting apparent molar expansibility, and isobaric thermal expansion coefficient. Furthermore, the experimental densities were fitted to some mathematical equations such as Jouyban-Acree, Jouyban-Acreevan't Hoff, modified Jouyban-Acree-van't Hoff, Redlich–Kister and Emmerling. Studies of this nature can provide useful insights into solute–solvent interactions in aqueous solutions of DES, especially about to their novel application in drug solubilization. [ABSTRACT FROM AUTHOR]

The main purpose of this research was to evaluate the mass/volume percentage (%m/v) solubility of acetaminophen (ACP) in {ethanol (EtOH) (1) + propylene glycol (PG) (2) + water (3)} mixtures from 20.0 to 40.0 °C to expand the solubility database of this drug in mixed pharmaceutical solvents useful for designing high concentrated liquid products including injectable solutions. This is because ACP is an analgesic drug widely used available for oral administration as tablets or solutions. Besides, as injectable products, it is only available for perfusion in as 1 g in 100 mL (1.0%m/v). However, it is not available as 5 mL ampules for supplying doses of 500 mg. As demonstrated in this research some cosolvent mixtures allow ACP concentrations higher than 10.0%m/v, for instance the aqueous ternary mixture with 20% w/w of ethanol and 30% w/w of PG, among other possible mixtures. Flask shake method and UV–vis spectrophotometry were used for ACP solubility determinations at different temperatures. ACP solubility results are presented as Cartesian and triangular solubility profiles. ACP solubility increases with temperature arising and the cosolvent proportion in the mixtures. Maximum %m/v ACP solubility value is observed in the aqueous ethanol binary mixture of w1 = 0.80 at all temperatures being 21.18% at 25.0 °C. All the solubility values were well correlated using the Jouyban-Acree model obtaining mean percentage deviations of 3.8% (N = 330). In this way, %m/v equilibrium solubility of ACP in {EtOH + PG + water} mixtures has been studied and correlated at several temperatures as contribution to preformulation studies of injectable homogeneous liquid pharmaceutical dosage forms. [ABSTRACT FROM AUTHOR]

The equilibrium molar solubility of 2-hydroxybenzoic acid (salicylic acid, SA) in pseudo-binary mixed solvents of choline chloride/propylene glycol deep eutectic solvent (ChCl/PG DES, 1:3 molar ratio) and water was determined by a shake flask method at 293.15-313.15 K and ambient pressure (85 kPa). Based on the results, the maximum solubility of SA was observed in neat DES at 313.15 K (0.7604 mol·L−1) whereas it was minimum in neat water at 293.15 K (0.0112 mol·L−1). X-Ray power diffraction analysis of solid phase presented no polymorphic transformation or solvate formation in the experiments. Moreover, the molar solubility of SA was modeled mathematically with various cosolvency models attaining the average percentage deviations smaller than 6.1%, except for the modified Wilson-van't Hoff (12.6%). Further, more favorable and entropy-driven of SA dissolution in ChCl/PG DES-rich mixtures was achieved from the apparent thermodynamic analysis. [ABSTRACT FROM AUTHOR]

This work presents the application of L-tartaric acid (L-TA), ascorbic acid (AA), and L-carnitine (L-CAR) as a safe and non-toxic alternative agent to enhance the aqueous solubility of baclofen (BAC). The solvent evaporation method was employed for co-crystallization in three stoichiometric ratios of the drug, coformer (1:1, 1:3, 1:5) and formulations were confirmed by X-ray diffractometry (XRD), differential scanning calorimetry (DSC), and Fourier transform infrared (FT-IR). DSC study revealed the presence of both endothermic and exothermic peaks in compounds containing AA and L-TA. With respect to the BAC, L-TA and BAC, AA, the appearance of new diffraction peaks that do not overlap with un-processed BAC may be the implication of a new structure. The intensity of some diffraction peaks disappeared or reduced significantly which may also imply the formation of a new crystal phase. The solubility of the multicomponents increased and surpassed the solubility of BAC. Overall, the new compounds show significantly higher drug solubility whereas their physical mixtures only demonstrate a marginal increase in BAC solubility. The high solubility records of BAC, AA and BAC, L-TA evidence the marked difference in solubility of the new compounds with respect to their physical mixtures. The saturation solubility of BAC, L-CAR compound did not show any improvement relative to the un-processed BAC. These findings confirm that a new crystal phase may not have been obtained during the co-crystallization of BAC and L-CAR. [ABSTRACT FROM AUTHOR]

Solubility behavior of amlodipine besylate (ADB) was investigated in the binary mixtures of ethylene glycol + 2-propanol at five different temperatures (293.2–313.2 K). The solubility results obtained from the shake-flask method are correlated with some reported cosolvency models (i.e. the van't Hoff, combined nearly ideal binary solvent/Redlich–Kister, the Jouyban–Acree, the Jouyban–Acree–van't Hoff, the mixture response surface, the modified Wilson, and Buchowski–Ksiazczak models). The accuracy of these models is investigated with the mean relative deviations of the back-calculated solubility data. [ABSTRACT FROM AUTHOR]

In the current work, a fluorescence "off–on" system was developed and validated for uric acid analysis in urine, based on fluorescein, H2O2 and gold nanoparticles (Au NPs). First, the fluorescence intensity of fluorescein was greatly quenched (off mode) in interaction with H2O2 in the presence of Au NPs, then fluorescence restoring occurred (on mode) with uric acid adding according to its good reduction activity for interaction with H2O2. The emission-enhancing value was well linearly depend on uric acid concentration in the range of 0.3–8.0 μg.mL−1 with a detection limit of 0.12 μg.mL−1. The results of the developed probe for uric acid analysis in real samples were compared to a standard method and their good compatibility showed the high potential of the probe for uric acid analysis in urine samples. [ABSTRACT FROM AUTHOR]

Mesalazine (5-ASA) is a medication utilized to treat inflammatory bowel diseases involving ulcerative colitis and Crohn's disease. Mesalazine has fewer side effects but the low solubility and bioavailability of it is responsible for its delayed onset of action. Hence, the goal of this study is to determine the molar solubility of 5-ASA in aqueous pseudo-binary mixtures containing low toxic biocompatible choline chloride/ethylene glycol deep eutectic solvent (ChCl/EG DES) with DES mass fraction of 0.0–1.0 using a shake-flask technique at 293.2–313.2 K and approximately 85 kPa. The experimental results indicated that the solubility of 5-ASA enhanced by addition of DES mass fraction and also increasing temperature. The molarity values of 5-ASA were then modelled by some traditional cosolvency models, and regressed each model parameters. The back-computed molarity of 5-ASA using the selected cosolvency models presented a good consistency with the experimental data (lower mean percentage deviation than 5.14%). Moreover, the Gibbs and van't Hoff equations were employed to compute the thermodynamic functions of 5-ASA dissolution process in ChCl/EG DES + water from the temperature dependency of solubility data. This analysis presented an endothermic and entropy-driven process of 5-ASA dissolution in ChCl/EG DES + water. Furthermore, enthalpy-entropy compensation analysis represented non-linear enthalpy dissolution vs. Gibbs free energy compensation plots with positive and negative slopes for 5-ASA whereas the positive and negative slopes were probably due to the enhance in solvation of 5-ASA by ChCl/EG DES molecules and the solvent-structure loosing, respectively. [ABSTRACT FROM AUTHOR]

Drug solubility is of central importance to the pharmaceutical sciences, but reported values often show discrepancies. Various factors have been discussed in the literature to account for such differences, but the influence of manual testing in comparison to a robotic system has not been studied adequately before. In this study, four expert researchers were asked to measure the solubility of four drugs with various solubility behaviors (i.e., paracetamol, mesalazine, lamotrigine, and ketoconazole) in the same laboratory with the same instruments, method, and material sources and repeated their measurements after a time interval. In addition, the same solubility data were determined using an automated laser-based setup. The results suggest that manual testing leads to a handling influence on measured solubility values, and the results were discussed in more detail as compared to the automated laser-based system. Within the framework of unavoidable uncertainties of solubility testing, it is a possibility to combine minimal experimental testing that is preferably automated with mathematical modeling. That is a practical suggestion to support future pharmaceutical development in a more efficient way. [ABSTRACT FROM AUTHOR]

Equilibrium mole fraction solubility of salicylic acid in nine aqueous-ethanolic mixtures, as well as in neat water and neat ethanol, was determined at seven temperatures from T = (293.15 to 323.15) K. Salicylic acid solubility in these mixtures was adequately correlated with well-known correlation/prediction methods based on Jouyban-Acree model. Apparent thermodynamic quantities, i.e. Gibbs energy, enthalpy, and entropy, for the dissolution and mixing processes, were computed by means of the van't Hoff and Gibbs equations. The enthalpy–entropy compensation plot of enthalpy vs. Gibbs energy of dissolution was not linear exhibiting positive slopes from neat water to the mixture of w1 = 0.30 and from the mixture of w1 = 0.50 to neat ethanol indicating enthalpy-driven drug transfer processes but negative in the interval of 0.30 < w1 < 0.50 indicating entropy-driven drug transfer processes from more polar to less polar solvent systems. Moreover, by using the inverse Kirkwood–Buff integrals it is observed that salicylic acid is preferentially solvated by water molecules in water-rich mixtures but preferentially solvated by ethanol molecules in those mixtures of 0.24 < x1 < 1.00. [ABSTRACT FROM AUTHOR]

A novel ratiometric fluorescent sensor was fabricated for the fast and facile determination of cyclosporine A (CsA). Due to the narrow therapeutic index of CsA, its desired therapeutic effects are evident within a limited range of blood concentration, indicating the fundamental role of therapeutic drug monitoring in CsA pharmacological response. In this study, a two-photon fluorescence probe based on the zeolitic imidazolate framework (ZIF-8) and norepinephrine-capped silver nanoparticles (AgNPs@NE) was employed for the quantification of the CsA in human plasma samples. In the presence of CsA, the fluorescent emission intensity of ZIF-8-AgNPs@NE was quenched. Under the optimum conditions, the proposed probe determines CsA in plasma samples in two linear ranges of 0.01 to 0.5 μg mL−1 and 0.5 to 10 μg mL−1. The developed probe demonstrates the advantages of a facile and fast platform with limit of detection as low as 0.007 μg mL−1. At last, this method was applied to find CsA concentration in four patients receiving oral CsA regimen which indicates it as a promising method for on-site detection applications. [ABSTRACT FROM AUTHOR]

Solubility profile of ketoconazole in the aqueous binary mixtures of ethylene glycol is measured by a shake-flask method at 293.2–313.2 K and mathematically represented by some cosolvency models (e.g. van't Hoff, the λh equation, the Yalkowsky, the Jouyban–Acree, and the Jouyban–Acree–van't Hoff models) and the models' performances are illustrated by mean relative deviations. The density values of ketoconazole saturated solutions are also determined and represented by Jouyban–Acree model. [ABSTRACT FROM AUTHOR]

This work aims to obtain the solubility, density and thermodynamic parameters of deferiprone in propylene glycol and ethanol. For this purpose, a shake-flask technique was applied for solid–liquid equilibration and the spectrophotometry method was employed for solubility measurement. Solubility and density of deferiprone in non-aqueous mixtures of propylene glycol and ethanol were measured in the temperatures 293.2–313.2 K. Some equations including van't Hoff, the Jouyban-Acree, the Jouyban-Acree-van't Hoff, the mixture response surface and modified Wilson equations were used for the mathematical data modeling. The apparent thermodynamic parameters of the deferiprone dissolution process were computed and reported. [ABSTRACT FROM AUTHOR]

Solubility of salicylic acid in binary mixtures of water and betaine/propylene glycol (Bet/PG, molar ratio of 1:5), betaine/ethylene glycol (Bet/EG, molar ratio of 1:3) or betaine/glycerol (Bet/Gly, molar ratio of 1:3) deep eutectic solvents (DESs) was investigated via the shake flask method at 293.15–313.15 K under atmospheric pressure (≈85 kPa). The results indicate that the solubility values are enhanced with mass fraction of each DES and temperature and DES containing PG is the best cosolvent. The Hansen solubility parameter (HSP) of salicylic acid, neat solvents of each DES and water was calculated and used to predict the solubility of drug in each neat solvent. The experimental solubility values were in good agreement with the ones predicted from HSPs. Three cosolvency models (Jouyban-Acree, Jouyban-Acree-van't Hoff and the modified version of Jouyban-Acree-van't Hoff) and two activity coefficient models (NRTL and UNIQUAC) were selected to correlate the solubility data. Based on the obtained percentage mean relative deviations (MRD%) for back-calculated data, all the investigated models show good correlation and validation. Additionally, investigation of the apparent thermodynamic analysis presented an endothermic and entropy-driven dissolution of salicylic acid in all cosolvent compositions including neat DESs and water. [ABSTRACT FROM AUTHOR]

A synchronous fluorescence spectroscopy (SFS) sensor for pethidine detection is described based on UiO-66 metal–organic frameworks (MOFs) modified with N-doped carbon quantum dots (N-CQDs) embedded in hydrogel nanocomposites. Benefitting from the inovative design of the doping method in the carbonaceous structure, N-CQDs were successfully deposited in the pores of the UiO-66 network. Then, N-CQDs were employed as a sensitive segment toward the target molecules. UiO-66 was used for sensitive and selective sensing of the bonding interactions between N-CQDs and pethidine so that the electron transfer process from UiO-66 to the pethidine-N-CQD complex results in quenching the SFS intensity of UiO-66. To embed the stable and suitable sensing interface for pethidine assessment, the designed nanomaterial was inserted into the hydrogel network. This nanocomposite hydrogel showed two well-resolved emission peaks at 300 nm and 350 nm under ∆λ = 70, which corresponded to N-CQDs and UiO-66, respectively. The SFS sensing platform was employed for ratiometric detection of pethidine with a low limit of detection of 0.002 μg mL−1 over a wide concentration range from 0.005 to 1.0 μg mL−1. The accurate monitoring of pethidine with a good recovery of 90.8–101.5% indicated their independency from matrix effects for pethidine detection in human plasma being a complicated biological matrix. Scheme 1. General procedure for synthesizing N-CQDs@UiO-66/PVA hydrogel-based nanoprobe and its application for pethidine determination [ABSTRACT FROM AUTHOR]

Context: Methadone can be abused and caused addictive and has various side effects. Therefore, the development of a fast and reliable diagnosis technique for its monitoring is essential. In this work, applications of C60, GeC59, SiC59, and BC59 fullerenes were investigated utilizing density functional theory (DFT) to find a suitable probe for methadone detection. The C60 fullerene indicated weak adsorption energy for methadone sensing. Therefore, for the construction of the fullerene with good property for methadone adsorption and sensing, the GeC59, SiC59, and BC59 fullerenes have been studied. The adsorption energy of GeC59, SiC59, and BC59 in the most stable complexes were calculated at -2.08, -1.26, and -0.71 eV, respectively. Although GeC59, SiC59, and BC59 all showed strong adsorption, only BC59 present a high sensitivity for detection. Further, the BC59 fullerene showing a proper short recovery time (about 1.11 × 10–6 s for methadone desorption). Water as a solution is used to simulate the behavior of fullerenes in the body fluids, and results indicated that the selected pure and complex nanostructures are stable in water. The UV–vis spectrums indicated that the after adsorption of methadone on the BC59 exhibits shift toward the lower wavelengths (blue shift). Therefore, our investigation indicated that the BC59 fullerene is an excellent candidate for methadone detection. Methods: The interaction of methadone with pristine and doped C60 fullerenes surfaces was calculated using the density functional theory calculations. The GAMESS program and M06-2X method with a 6-31G(d) basis set were used for computations. Since the M06-2X method overestimates the LUMO-HOMO energy gaps (Eg) of carbon nanostructures, the HOMO and LUMO energies and Eg were investigated at the B3LYP/6-31G(d) level of theory using the optimization calculations. UV-vis spectra of excited species were obtained through the time-dependent density functional theory. To simulate the human biological fluid, the solvent phase was also evaluated in adsorption studies, and water was considered a liquid solvent. [ABSTRACT FROM AUTHOR]

A fluorescence "turn-off" technique was used for the quantification of deferiprone (DEF) in the exhaled breath condensate. Fe (III)-doped carbon dots (CDs) were synthesized with a hydrothermal method as a fluorescent nanoprobe. The prepared Fe (III)-doped CDs selectively and sensitively detect DEF in the concentration range of 0.05–4.0 μg mL−1 using a fluorescence quenching mechanism and with a limit of detection of 0.012 μg mL−1. As DEF acts as a strong iron chelator, the probe has the potential for DEF analysis in the presence of major interfering chemicals. The significant properties of the prepared probe, such as high stability, low cost, quick analysis, and simple operation, make it a helpful tool in bioanalytical chemistry. A schematic representation of Fe (III)–doped carbon quantum dots as a nanoprobe for deferiprone analysis [ABSTRACT FROM AUTHOR]

The molar solubility of bosentan (BST) in mixtures of ethylene glycol (EG) + water at different temperatures from 293.15 to 313.15 K was measured by using the shake flask technique. Experimental solubility increased with increasing temperature and mass fraction of cosolvent; so that, the largest solubility was found in neat cosolvent at 313.15 K. The cosolvency models of Jouyban–Acree and its combined version with van't Hoff equation (Jouyban–Acree–van't Hoff model) were used for correlation of BST solubility data with the low values of mean relative deviations (MRD% ≤ 8.1). Furthermore, some untested data were predicted based on the achieved trained models at 298.15 K. X-ray powder diffraction was also served to analyze the equilibrium solid phase crystal of BST and the results turns out that no polymorphic transformation, solvate formation or crystal transition during the whole solvent crystallization process. [ABSTRACT FROM AUTHOR]

The current study validated some trained models for predicting clozapine solubility data in mono- and binary-solvent mixtures. The prediction models were built by combining the van't Hoff and Jouyban–Acree models with various physicochemical characteristics such as Abraham solvation parameters and Catalan and Hansen solubility parameters. The overall mean relative deviation and cross-validation analyses were used to assess the models' accuracy and applicability. Validated models can be used to estimate the clozapine solubility in mono-solvents or solvent mixtures at various temperatures. [ABSTRACT FROM AUTHOR]

A salt-induced homogenous dispersive solid phase extraction method combined with an ionic liquid based-dispersive liquid–liquid microextraction was developed for the extraction of two aminoglycoside antibiotics (gentamicin and streptomycin) form milk samples prior to their determination by high performance liquid chromatography-tandem mass spectrometry. For this purpose, 15 mL milk sample mixed with 300 mg trichloroacetic acid to precipitate the sample proteins. After vortexing (1 min) and centrifugation (for 3 min at 5000 rpm), the supernatant was transferred into another test tube. After adjusting the solution pH at 10, polyvinylpyrrolidone (75 mg) was dissolved in it. The homogenous phase was broken by adding sodium chloride (20%, w/v) and polyvinylpyrrolidone was precipitated as fine particles which acted as a sorbent. After centrifugation, the supernatant phase was discarded and the analytes were eluted from the sorbent surface using 1.25 mL methanol. Subsequently, methanol was mixed with 85 µL trihexyl(tetradecyl)phosphonium chloride and the mixture was quickly injected into sodium chloride solution (10%, w/v). After a few seconds, the extraction solvent collected on the top of the solution was used in determination of the analytes. Under optimal conditions calibration curves of the analytes were linear in the range of 1–500 ng mL−1. Also, limits of detection and quantification were 0.29 and 0.18 ng mL−1; and 1.0 and 0.61 ng mL−1 for gentamicin and streptomycin, respectively. The extraction recoveries were 87 and 93% for gentamicin and streptomycin, respectively. Acceptable relative standard deviations ≤ 6.1% were also obtained. At last, the studied antibiotics were successfully determined in milk samples. [ABSTRACT FROM AUTHOR]

In the present study, sucrose-capped gold nanoparticles (Suc-AuNPs) were synthesized and used as a nanoprobe for the daclatasvir (DAC) detection using its localized surface plasmon resonance (LSPR) property. The determination mechanism was experimentally shown using UV–Vis, dynamic light scattering, and transmission electron microscope (TEM) measurements. The DAC detection is accompanied by the color change from pink to blue following a decrease in the LSPR band of Suc-AuNPs after adding various concentrations of DAC. Under the optimum condition, a good limit of detection (LOD) of 0.008 μg.mL−1 with a linear concentration response range of 0.01–1.0 µg.mL−1 was determined at 523 nm for DAC in exhaled breath condensate (EBC) sample. Moreover, the linearity range of 0.1–2.0 µg.mL−1 and LOD of 0.044 µg.mL−1 was obtained for DAC in the plasma sample. The employment of Suc-AuNPs for the determination of DAC in EBC samples exhibited high stability, simplicity, and repeatability which can be considered a routine method in clinical laboratories. [ABSTRACT FROM AUTHOR]

The Jouyban–Acree model is reported to be the most accurate mathematical model for predicting drug solubility in the mixed solvents at various temperatures. In this study, the solubility of ketoconazole is predicted using the Jouyban–Acree based general models in some previously reported co-solvency systems. For this purpose, parameters of the Hansen solubility and the Abraham solvation parameters are combined with the Jouyban–Acree model and are trained with reported solubility data for ketoconazole to reach predictive co-solvency models. For investigation of the models' accuracies, the values for mean relative deviations of predicted data from published experimental values are calculated and discussed. [ABSTRACT FROM AUTHOR]

The solubility of allopurinol was measured at several temperatures (15–35 ºC) in ethanol–water, ethanol–ethyl acetate, and ethyl acetate–hexane mixtures. The mole fraction solubility shows two solubility maxima against the co-solvent (ethanol) ratio (70 % ethanol–water and 100 % ethyl acetate) at each of the five temperatures studied. The authors correlated the solubility data in binary solvent mixtures at various temperatures using a modified version of the Jouyban–Acree model. The respective apparent thermodynamic functions Gibbs energy, enthalpy, and entropy of solution were obtained from the solubility data through the van't Hoff equations. The apparent enthalpies of solution are endothermic and display a maximum at 20 % ethanol in water, as ethanol is added to water, the entropy of the system increases. In the non-aqueous mixture (ethanol–ethyl acetate), enthalpy is the driving force throughout the whole solvent composition. An enthalpy–entropy compensation analysis confirms a non-linear enthalpy–entropy relationship in plots of enthalpy vs. Gibbs energy of solution, i.e., two different mechanisms involved in the solubility enhancement. An inverse Kirkwood–Buff integral analysis of the preferential solvation indicated that in ethanol-rich mixtures, the drug is preferentially solvated by water, and it is acting mainly as a Lewis base in front to water. [ABSTRACT FROM AUTHOR]

The current review summarized the progress that has been made over the years for the colorimetric determination of corticosteroids using chromophore reagents. Following an introduction to the subject and the fundamentals of colorimetric detection of corticosteroids, the chromophoric reagents were described in detail, and a perspective on the future of these materials was proposed. Different chromophores and various colorimetric reactions used for the detection of corticosteroids in real samples were reviewed. The key point of this review is to investigate and collect the colorimetric methods to improve the sensors based on image analysis, wearable sensors, and smartphones for corticosteroids in the future. [ABSTRACT FROM AUTHOR]

In the current study, a fluorometric probe based on molecularly imprinted polymers @ N-doped carbon dots (MIP@N-CDs) is reported for phenobarbital analysis in the exhaled breath condensate collected from the expiratory circuit of the mechanical ventilator (MVEBC). The detection mechanism is based on a charge transfer between N-CDs and phenobarbital that is selectively adsorbed on the active site of MIP. As the decrease in emission intensity is proportional to phenobarbital concentration, a method is proposed for its determination. This method has a linear relationship with phenobarbital concentration in the range of 0.01–8.0 mg L−1 with the relative standard deviation of < 2.0%. The current method is employed for the quantification of phenobarbital in MVEBC of the pre-term newborn babies receiving phenobarbital under a mechanical ventilator. [ABSTRACT FROM AUTHOR]

In organic solvents, water is the most frequently found impurity. It interferes with many reactions, so it can be a reason for importance of its determination. Karl Fischer titration is a commonly used method for this purpose. However, some disadvantages particularly the inability of continuous analysis limit its applications. The current study reviews the optical sensors/nanosensors developed for the determination of water and demonstrates their applications in checking water impurity in organic solvents. Such optical sensors are highly demanded in the sensing procedures due to their simplicity and low price. Almost these methods do not need any expensive or complicated vehicles. This review focuses on optical sensors/nanosensors for the quantification of water content in organic solvents from 2016 to 2020 and is an update of Jung et al. work in 2016. The reported sensors/nanosensors are categorized into two types: spectrophotometry and spectrofluorimetry; each of them is classified based on the used materials for water sensing. The details of each reported method are explained in this review in detail, and their analytical characteristics are given as a table. [ABSTRACT FROM AUTHOR]

Solubility determination of poorly water-soluble drugs is pivotal for formulation scientists when they want to develop a liquid formulation. Performing such a test with different ratios of cosolvents with water is time-consuming and costly. The scarcity of solubility data for poorly water-soluble drugs increases the importance of developing correlation and prediction equations for these mixtures. Therefore, the aim of the current research is to determine the solubility of acetylsalicylic acid in binary mixtures of ethanol+water at 25 and 37°C. Acetylsalicylic acid is non-stable in aqueous solutions and readily hydrolyze to salicylic acid. So, the solubility of acetylsalicylic acid is measured in ethanolic mixtures by HPLC to follow the concentration of produced salicylic acid as well. Moreover, the solubility of acetylsalicylic acid is modeled using different cosolvency equations. The measured solubility data were also predicted using PC-SAFT EOS model. DSC results ruled out any changes in the polymorphic form of acetylsalicylic acid after the solubility test, whereas XRPD results showed some changes in crystallinity of the precipitated acetylsalicylic acid after the solubility test. Fitting the solubility data to the different cosolvency models showed that the mean relative deviation percentage for the Jouyban-Acree model was less than 10.0% showing that this equation is able to obtain accurate solubility data for acetylsalicylic acid in mixtures of ethanol and water. Also, the predicted data with an average mean relative deviation percentage (MRD%) of less than 29.65% show the capability of the PC-SAFT model for predicting solubility data. A brief comparison of the solubilities of structurally related solutes to acetylsalicylic acid was also provided. [ABSTRACT FROM AUTHOR]

A simple analytical method was developed to quantify indoxyl sulfate (InS) in plasma using a salting-out assisted liquid–liquid extraction and spectrofluorimetry. Plasma samples were deproteinized by acetonitrile. Then, sodium chloride solution was added to separate acetonitrile and aqueous phase. The fluorescence intensity of InS which extracted to acetonitrile phase was determined by spectrofluorimetry. The method of presentation has a linear range between 2.5 and 40 µg/ml with a coefficient of determination (R2) of 0.995. Accuracy (% error) and precision (relative standard deviation) were 15% at nominal concentration and less than 15% at all levels, respectively. This established analytical method, which is sensitive and reproducible, could be applied for the quantification of InS in real plasma samples. [ABSTRACT FROM AUTHOR]

A redox reaction-based colorimetric method was validated for the qualitative assay and quantitative determination of paracetamol in exhaled breath condensate (EBC). Fe (III) and K3[Fe(CN)6] were used as colorimetric reagents in which paracetamol reduces Fe (III) to Fe (II) due to its reducing property. The produced Fe (II) is chelated with K3[Fe(CN)6] to form prussian blue colored product which can be detected by the naked eye in the range of 0.2–10.0 μg mL−1. The fully validated method was used for the determination of paracetamol in EBC of paracetamol poisoning individuals. [ABSTRACT FROM AUTHOR]

Solubility of meloxicam in {methanol + water} mixtures from 293.15 to 313.15 K has been determined and correlated by means of the Jouyban–Acree model. By using the van't Hoff and Gibbs equations the respective apparent thermodynamic quantities for the dissolution and mixing processes, namely Gibbs energy, enthalpy, and entropy, were calculated. A non-linear enthalpy–entropy relationship was observed in the plot of enthalpy vs. Gibbs energy exhibiting negative but variable slopes in the composition region 0.00 < x1 < 0.60 and variable negative and positive slopes in the other mixtures. Based on the inverse Kirkwood–Buff integrals it follows that meloxicam is preferentially solvated by water molecules in water-rich mixtures but preferentially solvated by methanol molecules in mixtures 0.31 < x1 < 1.00. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DESs) have widely applied in various fields. Given this and that DESs has low toxicity and are green solvents, new aspects of these solvents have been recently considered by researchers. In this review, after a brief explanation of different types and the physicochemical properties of DESs, i.e., melting temperature, volatility, viscosity, electric conductivity; their applications in extraction of various compounds e.g. organic and inorganic chemicals, pharmaceuticals, pesticides and proteins, biodiesel production, pharmaceutical applications, catalyst and gas capture were presented so that researchers can find out about the new aspects of these solvents. [ABSTRACT FROM AUTHOR]

Purpose: Electromembrane extraction is a new membrane-based extraction method in which charged compounds are extracted by an electric field. So far, this method has been used to extract and isolate a variety of acidic and basic drugs from various samples, including blood and plasma. However, in this procedure, it is not yet clear whether only unbound fraction of a drug is extracted or the total drug. The aim of this study is to reveal the nature of drug extraction in the presence of plasma proteins. Methods: To determine the nature of the extraction, the electromembrane extraction was performed from plasma solutions of phenytoin with concentrations 0.03 and 1.0 μg/mL, then the result was compared with the values obtained from the electromembrane extraction of ultrafiltrate of the same solutions (free concentration) and protein-free ultrafiltrate of plasma with final concentration of 0.03 and 1.0 μg/mL (total concentration). For this purpose, EME followed by capillary electrophoresis coupled with diode array detection was optimized and validated. Results: The results showed that the electromembrane extraction method was only able to extract the unbound fraction of phenytoin from plasma samples. The method was validated over a concentration range of 0.03–4 μg/mL. The inter and intra-assay precisions were less than 6.7%. The phenytoin protein binding was also determined to be in agreement with the literature data and confirms the validity of this method. Conclusion: This sensitive and quick EME approach for determining the free concentration of a phenytoin, can be a good alternative to classic methods for therapeutic drug monitoring and pharmacokinetic studies. [ABSTRACT FROM AUTHOR]

The reported experimental density and viscosity of polyethylene glycol 600 + methanol, ethanol, 1-propanol, and 2-propanol were mathematically represented using a simple and single mathematical model, namely, the Jouyban–Acree model. The results obtained revealed that one may accurately calculate the density, viscosity, and the physico-chemical properties derived from these values using a single mathematical model. [ABSTRACT FROM AUTHOR]

In the world of nanotechnology, graphene quantum dots (GQDs) have been considerably employed in numerous optical sensing and bioanalytical applications. Herein, a simple and cost-efficient methodology was developed to the quantification of deferiprone in plasma samples by utilizing the selective interaction of the GQDs and drug in the presence of Fe3+ ions. GQDs were synthesized by a bottom-up technique as an advantageous fluorescent probe. Increasing levels of deferiprone ranging from 5 to 50 mg.L−1, leads to significant fluorescence quenching of GQDs. In addition, the calibration curve was revealed a linear response in this range with a sensitivity of 5 mg.L−1. The method validation was carried out according to the FDA guidelines to confirm the accuracy, precision, stability and selectivity of the developed method. The results show that this green and low-cost fluorescent probe could be used for the analysis of deferiprone. [ABSTRACT FROM AUTHOR]

This study aimed to develop a determination method of mycophenolic acid (MPA) in biological samples using salting-out liquid–liquid microextraction from human plasma samples based on the formation of a fluorescent complex with terbium ion and its application in quantification of the MPA in clinical samples. MPA extracted from plasma samples by salting-out liquid–liquid microextraction after protein precipitation by acetonitrile. Then, the fluorescence intensity was measured at 545 nm using an excitation wavelength of 347 nm after optimization of extraction parameters. Under the optimum conditions for the developed method, it provided a linear range between 0.5 and 5.0 µg/mL with a correlation coefficient (R2) of 0.998, and then, the validation was performed according to the FDA guideline and the developed method could quantify MPA concentration in real plasma samples. The results showed that linearity, accuracy, and precision of the developed analysis method were suitable for the determination of the MPA in plasma samples. [ABSTRACT FROM AUTHOR]

A colorimetric nanoprobe was developed for the quantification of tobramycin in exhaled breath condensate (EBC). The nanoprobe consists of silver nanoparticles (Ag NPs) modified with sodium dodecyl sulfate (SDS), which is applied in the presence of sodium metaborate. Characterization of the synthesized SDS-capped Ag NPs by transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX) showed that the nanoparticles were well synthesized with nearly uniform size and an average diameter of < 30 nm. Interaction of sodium metaborate with the SDS-capped Ag NPs and tobramycin results in aggregation of the nanoparticles and consequently decreases the absorbance intensity, leading to the production of a new absorbance peak and a color change from yellow to purple. The absorbance intensity was recorded at λmax = 400 nm and 522 nm and λ522/λ400 was used as the analytical signal. The experimental parameters were investigated and optimized using a multivariate optimization method (central composite design). The current nanoprobe gives a linear response for tobramycin from 1.0 to 50.0 ng mL−1 with a detection limit of 0.5 ng mL−1. The intra- and inter-day relative standard deviations for five replicated analyses of 10.0 ng mL−1 tobramycin are 2.8% and 4.2%, respectively. [ABSTRACT FROM AUTHOR]

The ability of a number of common models for correlating the collected solubility data of drugs in ethanol + water mixtures (the number of data sets is 43) was tested. The selected models are classified within three groups, (1) λ–h, van't Hoff and Apelblat models with temperature dependency, and modified Wilson with solvent composition dependency, (2) Jouyban–Acree, Jouyban–Acree–van't Hoff and Jouyban–Acree–Apelblat (linear models) and NRTL, Wilson and UNIQUAC (nonlinear models) with both temperature and solvent composition dependencies, (3) UNIFAC, Yalkowsky, log–linear model of Yalkowsky, Jouyban–Acree–Abraham and Jouyban–Acree–Hansen predictive models. Of the models in group 1, the Apelblat model has the lowest overall %ARD and Jouyban–Acree–van't Hoff and Jouyban–Acree–Apelblat models in group 2 performed best in correlations. Moreover, predictions using Jouyban–Acree–Abraham and Jouyban–Acree–Hansen models in group 3 have the lowest %ARDs in this group. [ABSTRACT FROM AUTHOR]

Background: This short communication reports a new hypothesis regarding bioequivalence of inhalation products which can potentially provide a reliable means to compare pharmaceutical aerosol formulations and inhalers. Methods: Available methods regarding the bioequivalence studies, inhaled drugs and advantages of exhaled breath condensate (EBC) samples were reviewed to develop this hypothesis. Results: It is postulated that two inhalation products providing the same drug concentrations in airway lining fluid (ALF) could be considered bioequivalent. The use of EBC tests which reflect ALF composition can be recommended as an alternative to current testing methods for consideration of bioequivalence. Conclusion: The methods based on EBC analysis can potentially be applied to bioequivalence study of inhalation products and could reflect drug concentration in ALF. However, experimental studies would be necessary to support or refute this hypothesis on the novel application of EBC to bioequivalence in the future. [ABSTRACT FROM AUTHOR]

In contrast to bronchial and nasal lavages, the analysis of exhaled breath condensate (EBC) is a promising, simple, non-invasive, repeatable, and diagnostic method for studying the composition of airway lining fluid with the potential to assess lung inflammation, exacerbations, and disease severity, and to monitor the effectiveness of treatment regimens. Recent investigations have revealed the potential applications of EBC analysis in systemic diseases. In this review, we highlight the analytical studies conducted on non-volatile compounds/biomarkers in EBC. In contrast to other related articles, this review is classified on the basis of analytical techniques and includes almost all the applied methods and their methodological limitations for quantification of non-volatile compounds in EBC samples, providing a guideline for further researches. The studies were identified by searching the SCOPUS database with the keywords “biomarkers,” “non-volatile compounds,” “determination method,” and “EBC.” [ABSTRACT FROM AUTHOR]

Terbium-sensitized fluorescence is one of the simple and sensitive methods for quantification of drugs in biological and food samples. Silver nanoparticles (AgNPs) can enhance the intensity of terbium-sensitized fluorescence and provide a more sensitive method. Enrofloxacin (ENR) is one of the common antibiotics, and the determination of its residue in animal products is recommended because of its problems for human health. Various parameters affecting the fluorescence intensity were optimized using response surface methodology. Then, the optimized parameters were applied to the validation of method for ENR quantification in milk samples. The linearity of the method was from 0.050 to 0.60 mg/L, and the limit of detection (LOD) and limit of quantification (LOQ) of the method were 0.021 to 0.069 mg/L, respectively. The accuracy, precision, and selectivity studies of the developed method give reasonable results. These data showed that the established analysis approach is a simple and sensitive technique for monitoring of ENR in milk samples. [ABSTRACT FROM AUTHOR]