Solubility Measurement, Correlation, and Thermodynamic Analysis of N-Acetyl-l-leucine in 12 Pure Organic Solvents from 283.15 to 323.15 K

Abstract

The solubility of N-acetyl-l-leucine in 12 mono organic solvents (methanol, ethanol, n-propanol, 2-propanol, 1-butanol, isobutanol, 2-butanol, methyl acetate, ethyl acetate, propyl acetate, acetone, and acetonitrile) was determined by the gravimetric method over the temperatures ranging from 283.15 to 323.15 K at 0.1 MPa. The solubility of N-acetyl-l-leucine in each experimental solvent increases with increasing temperature. Moreover, the solubility is an order of magnitude higher in alcohol solvents than in other solvents, which is mainly attributed to the hydrogen bond formation. In addition, the experimental solubility data are correlated by three models, including the modified Apelblat equation, λh equation, and the nonrandom two-liquid (NRTL) model. All of the average relative deviation % values are less than 3.72%, which indicates that the three models have satisfactory correlations. Furthermore, the mixing thermodynamic properties of N-acetyl-l-leucine in 12 mono solvents including Δmix G 0, Δmix H 0, and Δmix S 0 are calculated based on the NRTL model, indicating that the mixing process was spontaneous.

Solubility of 2-Amino-5-chloro-3-methylbenzoic Acid in Ten Pure Solvents and Three Groups of Binary Mixed Solvents at T = 278.15–323.15 K

“…The solubility of 2-amino-5-chloro-3-methylbenzoic acid in different solvent systems was determined by gravimetric analysis. This method has been used in many studies and proved its reliability. − First, we added an excess of 2-amino-5-chloro-3-methylbenzoic acid and 8 mL of different solvents into a 10 mL stoppered glass test tube. Second, these glass test tubes were fixed in a double-layer glass container filled with water and connected to a smart constant-temperature water bath to maintain a constant temperature.…”

Measurement and Correlation of the Solubility and Thermodynamic Properties of Ribavirin(II) in Nine Pure Solvents and (1-Propanol + Water) Binary Solvents

“…Drug preparation and utilization, such as crystallization and formulation, require the corresponding solubility data. 1 Crystallization is a complex mass and heat transfer process and is influenced by the changes in physical and chemical conditions. 2 Suitable solvents and operating conditions are important for the synthesis and crystallization of drugs.…”