Solid-liquid equilibrium of nicotinamide in water-ethanol and water-propylene glycol mixtures
TL;DR: In this paper, the Apelblat model showed a good correlation in both solvent systems, the best predictive fit model, and the experimental results were compared with a correlative thermodynamic model, three activity coefficient models (Wilson, UNIQUAC, NRTL), and with literature data.
About: This article is published in Journal of Molecular Liquids.The article was published on 2022-01-01. It has received 2 citations till now. The article focuses on the topics: UNIQUAC & Non-random two-liquid model.
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TL;DR: The model allows stating that the adsorption of both the pharmaceutical compounds occurs via the formation of one or two layers on MAC adsorbent, the propranolol showing a higher tendency to form multiple layers.
8 citations
TL;DR: In this paper , the density and dynamic viscosity of the mixed solvents propylene glycol (PG) and macrogol 400 (M400) were studied over the entire concentration range at temperatures from 293.15 to 313.15 K.
Abstract: Aim. To study the density and dynamic viscosity of the mixed solvents propylene glycol (PG) – macrogol 400 (M400), to calculate their excess values and excess activation parameters of viscous flow, to evaluate the features of the structure of the mixed solvents and its influence on the in vitro release of PG and M400.
Materials and methods. The mixed solvents PG - M400 were studied over the entire concentration range at temperatures from 293.15 to 313.15 K. The density and dynamic viscosity were determined, and the excess density, excess dynamic viscosity, activation parameters of viscous flow, and excess activation parameters of viscous flow were calculated. The in vitro release of PG and M400 from the mixed solvents was studied using vertical diffusion cells. The content of PG and M400 in the receptor medium was determined by gas chromatography using validated analytical procedures. The release rate, cumulative content, percentage of released PG or M400, coefficients of correlation and coefficients of determination were calculated.
Results. The isotherms of excess density and excess dynamic viscosity of the mixed solvents PG-M400 pass through a maximum. The enthalpy makes the main contribution to the free activation energy of the viscous flow. The excess free energy is positive and has small values; the values of the excess entropy and excess enthalpy are negative, and the isotherms have the minimum at PG concentrations of 70‑75mol %. The release parameters of M400 are greater in binary mixtures where the M400 structure predominates. At PG content of ~75 mol %, the release parameters for PG and M400 are identical. With the increase in PG content above 75 mol %, when the PG structure predominates in the system, the release parameters of PG increase dramatically, and the release parameters of M400 decrease sharply.
Conclusions. The structure of the binary system PG – M400 depends on its composition. Based on the isotherms of excess activation of viscous flow, it is possible to differentiate the areas where the structure of PG or the structure of M400 dominates, or the mixed structure of the binary solvent prevails. The in vitro release parameters for PG and M400 depend on the structure of the mixed solvents. The greatest difference in the release parameters of PG and M400 was observed in the area where the structure of PG dominates
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TL;DR: In this article, the authors introduce the notion of uniformity of intensive potentials as a criterion of phase equilibrium, and propose a model for solubilities of solids in liquid mixtures.
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TL;DR: In this article, the apparent molar enthalpies of solution atT =298.15 K were derived from these solubilities, and the resulting values are ΔsolHm(o-C9H8O4,m=0.0226 mol kg−1)=22.9 kJ mol−1.
1,105 citations
220 citations
TL;DR: This work investigated the applicability of the thermodynamic model perturbed-chain statistical associating fluid theory (PC-SAFT) to correlate and to predict the solubility of exemplary five typical drug substances and intermediates in pure solvents and solvent mixtures.
183 citations