Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Thermodynamics of antiviral and antiparkinsonian drug amantadine hydrochloride: condensed state properties and decomposition



Ala Bazyleva, Andrey V. Blokhin, Dzmitry H. Zaitsau, Gennady J. Kabo, Yauheni Paulechka, Andrei F. Kazakov, John M. Shaw


Heat capacities of antiviral and antiparkinsonian drug amantadine hydrochloride in the crystalline state were measured by adiabatic and differential scanning calorimetry in the temperature range from (5 to 470) K. Two unresolved low-enthalpy solid-to-solid phase transitions with peak maxima at 120.0 and 123.1 K were detected. Thermodynamic functions for crystalline amantadine hydrochloride were derived from the data obtained. Decomposition of amantadine hydrochloride was studied by the Knudsen effusion method. Quantum chemical calculations supported completeness of the amantadine hydrochloride ionic pair disintegration under the effusion conditions. A data treatment model considering the difference in effusion rates of the decomposition products, anisotropy failure in the vicinity of the orifice, and vapor undersaturation in the effusion cell was developed. Thermodynamic parameters for the decomposition were thus derived and shown to be in agreement with available literature data on decomposition of similar organic hydrochlorides and with the entropy of reaction calculated directly from the entropies of the decomposition reaction participants. The obtained set of thermodynamic properties of the medication is expected to provide new key information necessary for optimization of production and storage conditions.
Journal of Chemical and Engineering Data


Amantadine hydrochloride, thermodynamic properties, heat capacity, decomposition, effusion, quantum-chemistry calculations


Bazyleva, A. , Blokhin, A. , Zaitsau, D. , Kabo, G. , Paulechka, Y. , Kazakov, A. and Shaw, J. (2017), Thermodynamics of antiviral and antiparkinsonian drug amantadine hydrochloride: condensed state properties and decomposition, Journal of Chemical and Engineering Data, [online], (Accessed July 24, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created May 1, 2017, Updated November 10, 2018