title: Solubility and thermodynamic behavior of vanillin in propane-1,2-diol+water cosolvent mixtures at different temperatures.
abstract: The solubilities of bioactive compound vanillin were measured in various propane-1,2-diol+water cosolvent mixtures at T=(298-318)K and p=0.1 MPa. The experimental solubility of crystalline vanillin was determined and correlated with calculated solubility. The results showed good correlation of experimental solubilities of crystalline vanillin with calculated ones. The mole fraction solubility of crystalline vanillin was recorded highest in pure propane-1,2-diol (7.06×10(-2) at 298 K) and lowest in pure water (1.25×10(-3) at 298 K) over the entire temperature range investigated. Thermodynamic behavior of vanillin in various propane-1,2-diol+water cosolvent mixtures was evaluated by Van't Hoff and Krug analysis. The results showed an endothermic, spontaneous and an entropy-driven dissolution of crystalline vanillin in all propane-1,2-diol+water cosolvent mixtures. Based on solubility data of this work, vanillin has been considered as soluble in water and freely soluble in propane-1,2-diol.
authors.affiliation: Center of Excellence in Biotechnology Research, College of Science, King Saud University, P.O. Box 2460, Riyadh 11451, Saudi Arabia; Kayyali Chair for Pharmaceutical Industry, Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia. Electronic address: faiyazs@fastmail.fm.
authors.forename: Faiyaz
authors.initials: F
authors.lastname: Shakeel
authors.affiliation: Center of Excellence in Biotechnology Research, College of Science, King Saud University, P.O. Box 2460, Riyadh 11451, Saudi Arabia; Kayyali Chair for Pharmaceutical Industry, Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.
authors.forename: Nazrul
authors.initials: N
authors.lastname: Haq
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.
authors.forename: Nasir A
authors.initials: NA
authors.lastname: Siddiqui
authors.affiliation: Kayyali Chair for Pharmaceutical Industry, Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.
authors.forename: Fars K
authors.initials: FK
authors.lastname: Alanazi
authors.affiliation: Center of Excellence in Biotechnology Research, College of Science, King Saud University, P.O. Box 2460, Riyadh 11451, Saudi Arabia; Kayyali Chair for Pharmaceutical Industry, Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.
authors.forename: Ibrahim A
authors.initials: IA
authors.lastname: Alsarra
mesh_terms: D001547:Benzaldehydes / Q000737:chemistry*; D011407:Propane / Q000737:chemistry*; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D001547:Benzaldehydes; D012997:Solvents; D014867:Water; C100058:vanillin; D011407:Propane
keywords: Cosolvent mixture; Mathematical models; Propane-1,2-diol; Solubility; Thermodynamics; Vanillin