Journal of Thermal Analysis and Calorimetry

, Volume 113, Issue 1, pp 265–271 | Cite as

Thermal behaviour studies of procaine and benzocaine

Part 1. Kinetic analysis of the active substances under non-isothermal conditions
  • Adriana Fulias
  • Gabriela Vlase
  • Carmen Grigorie
  • Ionuţ Ledeţi
  • Paul Albu
  • Mihai Bilanin
  • Titus Vlase


The analysed substances, procaine and benzocaine, are two anaesthetic agents currently being administered in tablet form, also in the topical (cream, gel, balm) and injectable dosage forms. The TG/DTG/DTA curves were obtained in air at different heating rates. For determination of the heat effects, the DTA curves (in μV) were changed with the heat flow curves (in mW), so that the peak area corresponds to an energy in J g−1 or kJ mol−1. The non-isothermal experiments are preformed to investigate the thermal degradation process of these active substances, both as a solid and are performed in a dynamic atmosphere of air at different heating rates, by heating from room temperature to 500 °C. The kinetic analysis was performed using the TG data in air for the first step of substance’s decomposition at four heating rates: 7, 10, 12 and 15 °C min−1. The data were processed according to an appropriate strategy to the following kinetic methods: Kissinger–Akahira–Sunose, Flynn–Wall–Ozawa, Friedman and NPK, to obtain realistic kinetic parameters, even if the decomposition process is a complex one. Thermal analysis was supplemented using Fourier Transform infrared spectroscopy coupled with the TG device to identify the anaesthetics with any products which may have formed (EGA—the evolved gas analysis).


Procaine Benzocaine Kinetic parameters Non-isothermal conditions NPK method 


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Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2013

Authors and Affiliations

  • Adriana Fulias
    • 1
  • Gabriela Vlase
    • 2
  • Carmen Grigorie
    • 2
  • Ionuţ Ledeţi
    • 1
  • Paul Albu
    • 3
  • Mihai Bilanin
    • 2
  • Titus Vlase
    • 2
  1. 1.Faculty of Pharmacy, University of Medicine and Pharmacy “Victor Babeş”TimişoaraRomania
  2. 2.Research Centre for Thermal Analysis in Environmental Problems, West University of TimisoaraTimişoaraRomania
  3. 3.Pharmacy and Dentistry, Department of PharmacyFaculty of General Medicine, “Vasile Goldis” West University of AradAradRomania

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