| The main objective of this research was to determine and correlate the
equilibrium solubility of sodium sulfadiazine in several {cosolvent (1) +
water (2)} mixtures at 298.2 K. Cosolvents were formamide, N-methylformamide,
N,N-dimethylformamide, dimethyl sulphoxide, N-methyl-2-pyrrolidone,
1,4-dioxane, and methanol. Classical shake-flask method was used
to determine isothermal solubility. Drug concentration measurements were
performed by means of electrical conductivity determinations after adequate
aqueous dilutions. Solubility of sodium sulfadiazine decreases nonlinearly
with the addition of cosolvent to water in almost all mixtures
compositions. The Jouyban-Acree and Jouyban-Acree-Abraham models
correlate the solubility values with the mixtures composition for all cosolvent
systems. Furthermore, the apparent specific volume of this drug at
saturation was also calculated from density and mixtures compositions. |