Solubility of Carvedilol in Ethanol + Propylene Glycol Mixtures at Various Temperatures

Effect of 2-hydroxyethylammonium carboxylate protic ionic liquids on the solubility and cytotoxicity of indomethacin

Recently, there is a particular interest to utilize protic ionic liquids (PILs) in drug solubility. This study is exploring the effect of three protic ionic liquids (PILs) based on 2-hydroxyethylammonium carboxylate [2-hydroxyethylammonium acetate (MEAA), 2-hydroxyethylammonium lactate (MEAL), and 2-hydroxyethylammonium propionate (MEAP)] on the solubility of the very poorly soluble drug in water, indomethacin (IMC). The shake flask method was used to measure the experimental solubility of IMC at the different temperatures range (298.15-313.15) K. The results demonstrate significantly enhancment the solubility of IMC in PILs compared to pure water, with an approximate increase of 200 times. The experimental solubility data have been correlated using the empirical models which showed the performance as the order: Modified Apelblat-Jouyban-Acree > Van't Hoff-Jouyban-Acree > Modified Apelblat equations and also the performance for the Wilson model indicated as the order (absolute relative deviation): 2-hydroxyethylammonium acetate (3.030) > 2-hydroxyethylammonium propionate (3.239) > 2-hydroxyethylammonium lactate (7.665). Then the thermodynamic dissolution properties were obtained by usage of Gibbs and Van't Hoff equations to investigate the thermodynamic behavior of the IMC in the aqueous solution PILs. Eventually, the cytotoxicity of the co-solvents (PILs) under study was evaluated using a standard MTT assay. The results showed that the cell viability percentage increased in the following order: MEAA < MEAP < MEAL. These findings indicated that these PILs had low to moderate toxicity. It is noteworthy that the functional groups of the anions were not the only determinant factor of the cytotoxicity. Other factors encompassing concentration, exposure time, and cell line characteristics also had significant effects.

Smart biodegradable hydrogels: Drug-delivery platforms for treatment of chronic ophthalmic diseases affecting the back of the eye

This paper aims to develop smart hydrogels based on functionalized hyaluronic acid (HA) and PLGA-PEG-PLGA (PLGA,poly-(DL-lactic-co-glycolic acid); PEG,polyethylene glycol) for use as intraocular drug-delivery platforms. Anti-inflammatory agent dexamethasone-phosphate (0.2 %w/v) was the drug selected to load on the hydrogels. Initially, different ratios of HA-aldehyde (HA-CHO) and thiolated-HA (HA-SH) were assayed, selecting as optimal concentrations 2 and 3 % (w/v), respectively. Optimized HA hydrogel formulations presented fast degradation (8 days) and drug release (91.46 ± 3.80 % in 24 h), thus being suitable for short-term intravitreal treatments. Different technology-based strategies were adopted to accelerate PLGA-PEG-PLGA water solubility, e.g. substituting PEG1500 in synthesis for higher molecular weight PEG3000 or adding cryopreserving substances to the buffer dissolution. PEG1500 was chosen to continue optimization and the final PLGA-PEG-PLGA hydrogels (PPP1500) were dissolved in trehalose or mannitol carbonate buffer. These presented more sustained release (71.77 ± 1.59 % and 73.41 ± 0.83 % in 24 h, respectively) and slower degradation (>14 days). In vitro cytotoxicity studies in the retinal-pigmented epithelial cell line (RPE-1) demonstrated good tolerance (viability values > 90 %). PLGA-PEG-PLGA hydrogels are proposed as suitable candidates for long-term intravitreal treatments. Preliminary wound healing studies with PLGA-PEG-PLGA hydrogels suggested faster proliferation at 8 h than controls.

Micro-Solvation of Propofol in Propylene Glycol-Water Binary Mixtures: Molecular Dynamics Simulation Studies

The water microstructure around propofol plays a crucial role in controlling their solubility in the binary mixture. The unusual nature of such a water microstructure can influence both translational and reorientational dynamics, as well as the water hydrogen bond network near propofol. We have carried out all-atom molecular dynamics simulations of five different compositions of the propylene glycol (PG)/water binary mixture containing propofol (PFL) molecules to investigate the differential behavior of water microsolvation shells around propofol, which is likely to control the propofol solubility. It is evident from the simulation snapshots for various compositions that the PG at high molecular ratio favors the water cluster and extended chainlike network that percolates within the PG matrix, where the propofol is in the dispersed state. We estimated that the radial distribution function indicates higher ordered water microstructure around propofol for high PG content, as compared to the lower PG content in the PG/water mixture. So, the hydrophilic PG regulates the stability of the water micronetwork around propofol and its solubility in the binary mixture. We observed that the translational and rotational mobility of water belonging to the propofol microsolvation shell is hindered for high PG content and relaxed toward the low PG molecular ratio in the PG/water mixture. It has been noticed that the structural relaxation of the hydrogen bond formed between the propofol and the water molecules present in the propofol microsolvation shell for all five compositions is found to be slower for high PG content and becomes faster on the way to low PG content in the mixture. Simultaneously, we calculated the intermittent residence time correlation function of the water molecules belonging to the microsolvation shell around the propofol for five different compositions and found a faster short time decay followed up with long time components. Again, the origin of such long time decay is primarily from the structural relaxation of the microsolvation shell around the propofol, where the high PG content shows the slower structural relaxation that turns faster as the PG content approaches to the other end of the compositions. So, our studies showed that the slower structural relaxation of the microsolvation shell around propofol for a high PG molecular ratio in the PG/water mixture correlate well with the extensive ordering of the water microstructure and restricted water mobility and facilitates the dissolution process of propofol in the binary mixture.

Measurement and correlation of solubility data for deferiprone in propylene glycol and 2-propanol at different temperatures

This investigation dealt with the thermodynamic properties, saturated solubility values, and solvation behavior of deferiprone as an oral iron chelator agent in non-aqueous mixtures of propylene glycol and 2-propanol using experimental measurements and mathematical correlations. The solubility of deferiprone demonstrated a positive correlation with both temperature and propylene glycol mass fraction. Four mathematical models were employed to correlate the solid-liquid equilibrium data, and the low mean relative deviation values of less than 3.6% illustrate the good agreement of computed data with the experimental data. The apparent thermodynamic behavior of deferiprone dissolution was also investigated according to van't Hoff and Gibbs equation.

Solubility and Thermodynamics Profile of Benzethonium Chloride in Pure and Binary Solvents at Different Temperatures

Benzethonium chloride (BTC) has various applications in several industries. The solubility and solution thermodynamic properties of BTC were measured. The solubility of BTC in methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, water, dimethyl sulfoxide, acetic acid, and dimethyl formamide neat solvents and methanol + water and ethanol + water binary solvents at 298.15-318.15 K over an atmospheric pressure was measured. The solubility data of BTC is positively related to the temperature in all selected solvents. The solubility data was fitted by the Apelblat model, λh model, Yaws model, Van't Hoff equation, CNIBS/R-K model, and modified Jouyban-Acree equation. The RMSD and ARD were chosen to evaluate the fitting of each model. The dissolution thermodynamic parameters, enthalpy of the solution, entropy of the solution, and Gibbs energy of the solution were calculated. The solubility data and dissolution thermodynamic parameters of BTC will provide significant guidance for purification, crystallization, and separation in various areas.

Solubility and thermodynamic study of deferiprone in propylene glycol and ethanol mixture

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.

Effect of temperature and propylene glycol as a cosolvent on dissolution of clotrimazole

Herein, the solubility study of clotrimazole was performed in a propylene glycol+water system. The solubility values were fitted to various cosolvency equations. The model accuracies were studied with the computation of the mean relative deviations. The thermodynamic behavior was investigated according to the van't Hoff and Gibbs equations for clotrimazole in the propylene glycol+water system. Furthermore, the density data for clotrimazole were determined in mixtures of propylene glycol+water and fitted to the Jouyban-Acree equation.

Study of mesalazine solubility in ternary mixtures of ethanol, propylene glycol, and water at various temperatures

Mesalazine is a low-permeable and low-soluble drug, which makes it a class IV drug in the Biopharmaceutics Classification System. Hence, its solubilization can be helpful for various stages of formulation development. The purpose of this study was to investigate the solubilization manner and thermodynamics of mesalazine in ternary solvent combinations of {ethanol (1) + propylene glycol (2) + water (3)} using the shake-flask technique at (298.2-313.2) K. In the following, the mathematical representation of the acquired solubility data using some popular models was evaluated. The accuracies of the applied models were described by percentages of mean relative deviation (MRD%). Based on obtained results (MRD% < 10.0), it can be concluded that the trained models can adequately predict the solubility of mesalazine in the investigated ternary solvent combinations. The findings also revealed that the solution composition and temperatures greatly influence the solubility of mesalazine. In addition, the thermodynamic characteristics of the mesalazine dissolution process indicate that the mesalazine dissolution process is endothermic and entropy-driven. The generating data in the current work also expands the available solubility database for mesalazine in the solvent mixtures.

Formulation and development of novel control release transdermal patches of carvedilol to improve bioavailability for the treatment of heart failure

The main aim of this study is to optimize and evaluate transdermal patch of Carvedilol by the use of different polymer and different permeation enhancers which help to release drug in controlled action and thereby increase the bioavailability of the drug. Main objective was to avoid first pass metabolism of Carvedilol. Transdermal patches were developed by solvent evaporation method. The combination of Eudragit RS-100 as rate controlling polymer and Span 80 as a permeation enhancer was found to be ideal formulation (Formulation F7) with maximum drug release i.e. 100.29 ± 0.44 % within 12 h. Formulation F7 showed maximum bioavailability and showed maximum drop of BP at 6 h. From this study the conclusion was, transdermal patch of Carvedilol which contains Eudragit RS-100 polymer and Span 80 as penetration enhancer produced sustained and continued drug release.

Cytotoxicity of some choline-based deep eutectic solvents and their effect on solubility of coumarin drug

The effect of some deep eutectic solvents (DESs) on the coumarin solubility has been investigated using Hansen solubility parameters (HSP). The solubility of coumarin was measured in aqueous systems containing some DESs based on choline chloride (ChCl) as hydrogen bond acceptor (HBA) with urea (U), ethylene glycol (EG), and glycerol (GLY) as hydrogen bond donors (HBD) by widely applied shake-flask method at T = (298.15 to 313.15) K. The results indicate that coumarin solubility enhances with the concentration of DESs and temperature. Also, coumarin was dissolved more than 80 times compared with pure water in the presence of ChCl/EG. Then experimental data were fitted to Wilson, electrolyte Non-Random Tow-Liquid (e-NRTL), and UNIQUAC activity coefficient models. Furthermore, the dissolution thermodynamic properties including enthalpy, Gibbs free energy, and entropy have been calculated based on Gibbs and van't Hoff equations. Due to these results, it is indicated that coumarin dissolution in the studied systems is an endothermic process. Moreover, to investigate the biological properties of DESs, MTT assay have been applied to determinate cytotoxicity of the DESs. In the melanoma skin cell line, cell culture tests revealed that these solvents had very low toxicity and high biocompatibility.

Solubility Determination of c-Met Inhibitor in Solvent Mixtures and Mathematical Modeling to Develop Nanosuspension Formulation

The solubility and dissolution thermodynamics of new c-Met inhibitor, ABN401, were determined in eleven solvents and Transcutol^® HP-water mixture (TWM) from 298.15 to 318.15 K. The experimental solubilities were validated using five mathematical models, namely modified Apelblat, van't Hoff, Buchowski-Ksiazaczak λh, Yalkowsky, and Jouyban-Acree van't Hoff models. The experimental results were correlated and utilized further to investigate the feasibility of nanosuspension formation using liquid anti-solvent precipitation. Thermodynamic solubility of ABN401 increased significantly with the increase in temperature and maximum solubility was obtained with Transcutol^® HP while low solubility in was obtained water. An activity coefficient study indicated that high molecular interaction was observed in ABN401-Transcutol^® HP (THP). The solubility increased proportionately as the mole fraction of Transcutol^® HP increased in TWM, which was also supported by a solvent effect study. The result suggested endothermic and entropy-driven dissolution. Based on the solubility, nanosuspension was designed with Transcutol^® HP as solvent, and water as anti-solvent. The mean particle size of nanosuspension decreased to 43.05 nm when the mole fraction of ABN401 in THP, and mole fraction of ABN401 in TWM mixture were decreased to 0.04 and 0.1. The ultrasonicated nanosuspension appeared to give comparatively higher dissolution than micronized nanosuspension and provide a candidate formulation for in vivo purposes.

Solubility of codeine phosphate in carbitol + 2-propanol mixture at different temperatures

The solubility profile of codeine phosphate in the carbitol and 2-propanol mixtures at 293.2-313.2 K are determined and correlated with some developed cosolvency models. Moreover, the density values of codeine phosphate saturated solutions are also determined and fitted with the Jouyban-Acree model. The model accuracy is investigated by calculating the mean relative deviations (MRDs%). The thermodynamic parameters of codeine phosphate dissolution in the non-aqueous mixtures of carbitol and 2-propanol are also computed by using van't Hoff and Gibbs equations.