Thermal behavior of some phenitoine pharmaceuticals
The topic of the present work is to study the thermal behavior of phenitoine and pharmaceuticals by means of kinetic parameters determined in non-isothermal conditions.
The TG/DTG data were obtained at four heating rates. These data were processed by the following methods: Friedman (FR), Budrugeac-Segal (BS) and the modified non-parametric kinetics (Sempere-Nomen).
The main conclusions of the kinetic study are
The FR method is versatile, but the values of the kinetic parameters are not certain, especially by multistep processes.
The BS method offer a non-variant part of the activation energy, but the kinetic description is only formal.
The NPK method is able to discriminate between two or more steps of a complex process. In our case, there are a preponderant process (more than 70% of the explained variance).
By the NPK method there is a non-speculative separation of the temperature, respective conversion degree dependence of the reaction rate.
Keywordsnon-isothermal kinetics phenitoin thermal stability
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