masterThesis
Determinação da energia de ativação e pureza de medicamentos de referência, genérico e similar utilizando técnicas termoanalíticas
Fecha
2014-08-28Registro en:
PAULA, Sueilha Ferreira de Andrade de. Determinação da energia de ativação e pureza de medicamentos de referência, genérico e similar utilizando técnicas termoanalíticas. 2014. 136f. Dissertação (Mestrado em Química) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2014.
Autor
Paula, Sueilha Ferreira de Andrade de
Resumen
In this work, the reference drugs, generic and similar to the active ingredients acetylsalicylic
acid, paracetamol, captopril, hydrochlorothiazide and mebendazole were purchased from local
pharmacies and studied by thermogravimetry (TG) and Differential Scanning Calorimetry
(DSC). Thermal decomposition was assessed to obtain from the Ozawa method the activation
energy in inert atmosphere (nitrogen), using three different heating ratios (5, 10 and 20 o
C
min-1). The pharmaceutical formulation of the AAS reference was the one who presented
different from the others (generic and similar) Thermogravimetric profile indicating likely
interaction between the active ingredient and excipients. Was observed at the heating rate of
the inverse temperature that no linearity of the data, ie, there was no correlation between the
percentage of mass loss and the activation energy involved in the thermal decomposition of
the pharmaceutical formulation of the AAS reference log graph. The analysis by differential
scanning calorimetry was performed in nitrogen atmosphere with a heating rate of 10 ° C
min-1. In the analysis of these same drugs, the data curves found on the melting point were,
except for hydrochlorothiazide, are consistent with the literature. Hydrochlorothiazide
presented a melting point well below that found in the literature, which may be justified due
to the interaction of the active ingredient with the excipient lactose. In the study of purity,
using the Van't Hoff equation, the reference drugs hydrochlorothiazide and mebendazole
reference generic and showed similar impurity content below the limit established that this
equation must be greater than 2.5 mol%