Phase Separation Study of Imipramine Hydrochloride-Additive Systems

Phase separation study of an antidepressant drug, imipramine hydrochloride (IMP), in presence of various additives (i.e., alcohols, sugars, amino acids) has been made by cloud point (CP) measurements. Whereas the CP remained constant with lower alcohols, higher ones (due to their hydrophobic nature) decreased it and medium chain alcohols showed peaked behavior. With diols, the CP remained constant but showed peaked behavior with cycloalkanols. Sugars have a CP decreasing effect because of their water structure making property. All the amino acids increased the CP but to different extent. At different fixed [hexanol], the CP decreased with increasing pH while increase in drug concentration increased the CP. The results are discussed in terms of additive effects on bulk solvent (water) and drug morphology. In the presence and absence of C6OH, the thermodynamic parameters ([image omitted], [image omitted] and [image omitted]) of IMP at CP are found to be positive up to a certain C6OH concentration (90mM), and above this concentration, the [image omitted] values become negative.