Hydration and dehydration kinetics of xylazine hydrochloride

Abstract

From the experiments where mixture of xylazine hydrochloride hydrate H and anhydrous X were held at constant conditions, the stable form of xylazine hydrochloride can be found out. To determine equilibrium relative humidity, the unstable form of xylazine hydrochloride was inserted in thermostated humidity chamber and its weight was recorded by weighing the sample outside the chamber. The kinetic model and the rate constant for each condition were determined. The rate constants give information regarding the speed of the process at every experimentally used relative humidity. Thus using the data in coordinates k – p for each temperature it is possible to determine the water vapor pressure of the equilibrium. With this method the phase boundary for xylazine hydrochloride was determined and hydration enthalpy was calculated. The hydration rates of xylazine polymorphs A and X were investigated.

Keywords::

• Polymorphism
• xylazine hydrochloride
• hydrate
• hydration
• dehydration
• solid state kinetics

Acknowledgments

We would like to thank JSC Grindeks for supplying xylazine hydrochloride and the JSC Grindeks Fund for the support of the science and education scholarship for Agris Bērziņš.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.