Solubility of N-(4-chlorophenyl)-2-(pyridin-4-ylcarbonyl)hydrazinecarbothioamide in PEG 400 + water co-solvent mixtures at 298.15 K to 338.15 K

• Solubility of isoniazid analogue in various PEG 400 + water mixtures was measured.
• The solubility was found to be highest in pure PEG 400.
• Experimental solubilities were correlated with Apelblat equation and Yalkowsky model.
• Solubilities were increased with increase in temperature and mass fraction of PEG 400.

The solubility of N-(4-chlorophenyl)-2-(pyridin-4-ylcarbonyl) hydrazinecarbothioamide (isoniazid analogue) in mono-solvents (water and polyethylene glycol 400 (PEG 400)) and various PEG 400 + water co-solvent mixtures was measured from (298.15 to 338.15) K using the shake flask method. The experimental solubilities were correlated with Apelblat equation and log-linear model of Yalkowsky. The root mean square deviations were observed in the range of 0.007–0.052 for Apelblat equation. However, the mean absolute errors were observed in the range of (0.36–4.94)% for log-linear model of Yalkowsky. Experimental solubilities of isoniazid analogue were correlated well with Apelblat equation and Yalkowsky model. The solubility of isoniazid analogue was observed highest and lowest in pure PEG 400 (0.108 at 298.15 K) and pure water (5.17 × 10−7 at 298.15 K), respectively. Based on solubility results, isoniazid analogue has been considered as freely soluble in PEG 400 and practically insoluble in water. The solubility data of this study could be useful in formulation development of isoniazid analogue in pharmaceutical industries.