Solubility of celecoxib in N-methyl-2-pyrrolidone + 2-propanol mixtures at various temperatures

Abstract

The molar and the mole fraction solubilities of celecoxib was determined in binary mixtures of N-methyl-2-pyrrolidone (NMP) + 2-propanol (2-PrOH) of eleven different compositions at five different temperatures (between 293.2 K and 313.2 K). The molar solubility of the drug is highest in NMP with about 0.6 and 0.8 mol·L? 1, depending on the temperature, and decreases with decreasing mass fraction of NMP - resembling a sigmoid curve - by a factor of 3 to 5 in 2-PrOH. The lowest solubility of 4.4 -- 10? 2 mol·L? 1 at 293.2 K is observed at a local minimum of the curve at a mass fraction of the alcohol of 0.9. In a given solvent, the solubility of celecoxib increases with increasing temperature. The data serve for the extension of the library of solubilities of drugs in different solvents, relevant for pharmaceutical and chemical industries. They are further determined to compare the prediction ability of several mathematical cosolvency models: the log-linear model and its extension, the combined nearly ideal binary solvent Redlich-Kister model, the modified Wilson model, the general single model, and the Jouyban-Acree model in combination with the van't Hoff equation were applied. As result, the last model enabled the prediction of the solubility of celecoxib at all possible compositions of NMP + 2-PrOH mixtures at any temperature of interest with 17.1% overall mean percentage deviation. © 2016 Elsevier B.V.