Federal University of Paraíba – UFPB Unified Development and Medicine Assays Laboratories – LUDEM João Pessoa Brasil 58051-970 Cidade Universitária, Campus I – CCS Paraíba João Pessoa Brasil 58051-970 Cidade Universitária, Campus I – CCS Paraíba
The objective of this work was to develop
and validate a fast and reproducible method to determine the concentration
of metronidazole in drug substance and tablets. The samples were analyzed
by dynamic thermogravimetry, using 10, 20, 40, 60 and 80C min–1
heating rates in nitrogen and in nitrogen with synthetic air. Obtained data
were used in the Antoine and Langmuir equations in order to have the pressure
curves. Vapor pressure curves of drug and tablet of metronidazole were evaluated
using the mathematical indexes of difference factor, f1,
and similarity factor, f2,
to compare their profiles. The data showed that there is no significant difference
between the vapor pressure profiles of drug and tablet of metronidazole in
both environmental conditions, which confirms that the process is really vaporization.
The concentration of metronidazole was determined in the raw material and
tablets of the drug.