Thermal Characterization of Extracts Obtained from Different Parts of Nigella damascena (Ranunculaceae) by TG and DSC

Abstract

The increased search for herbal products has generated an increasing interest in improving the quality control of extracts by pharmaceutical industry since these are raw materials of great importance by their quality and versatility. Thermal analysis such as thermogravimetry (TG) is a technique of high sensitivity, reproductibility and rapid response to variations in mass, obtaining results related to the composition and thermal stability of the sample, being important to the characterization of raw plants. Thermogravimetric techniques and differential scaning calorimetry (DSC) used for the study of pre-formulation of drug-excipient compatibility have been gaining importance. These techniques are being used for the verification of possible interactions between drugs and excipients. Aiming at studying the behavior of a plant extract, using these thermoanalytical techniques, the plant species Nigella damascena semen and Nigella damascena herba was used. This plant has healing and anti-inflammatory properties. The methodology for obtaining the extract followed the European Pharmacopoeia methodology. The TG and DSC curves were obtained under nitrogen and air atmosphere (20 mL/min) at a heating rate of 10�C/min. The TG and DSC tests were analyzed within a temperature range from 25 to 1000�C.