Calculating critical relative humidity from solubility according to nonelectrolyte Wilson nonrandom factor model

Abstract

The critical relative humidity (H_cr) of 25 drugs and chemicals was determined by the air humidity in equilibrium (AHE) method. The relationship between the H_cr and the solubility was explored theoretically, and the H_cr was calculated according to the nonelectrolyte Wilson nonrandom factor (N-Wilson-NRF) model or Raoult’s law from their solubility. The results indicate that the calculated H_cr is comparable to the measured one.

Keywords::

• Critical relative humidity
• air humidity in equilibrium method
• nonelectrolyte Wilson nonrandom factor model
• Raoult’s law
• solubility

Declaration of interest

The authors are grateful to the National Natural Science Foundation of China for financial support.