Equilibrium solubility and apparent specific volume at saturation of sodium sulfadiazine in some aqueous cosolvent mixtures at 298.2 K

ABSTRACT

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 non-linearly 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.

KEYWORDS:

• Sodium sulfadiazine
• cosolvents
• solubility
• cosolvency
• apparent specific volume
• Jouyban-Acree model

Acknowledgements

We thank the Department of Pharmacy of the Universidad Nacional de Colombia for facilitating the reagents, equipment and laboratories used.

Disclosure statement

No potential conflict of interest was reported by the authors.