DSC purity analysis is based on thermodynamic phase diagrams for substances (purity ≥98%) which undergo a melting point. Impurities
which have eutectic behaviour with the analyte are determined together.
DSC purity analysis obtained from a single melting event of a 1–2 mg sample is, therefore, extremely attractive for the global
assessment of eutectic impurities. The main advantages in early development lie in the very small amount of material necessary
and the very fast analysis time.
However, the DSC purity analysis cannot replace chromatographic methods which deliver specific individual levels of impurities.
Furthermore, a complete validation of a DSC purity method is difficult and time consuming. Despite these limitations, DSC
is the best support for the development of chromatographic methods, for purity profile and stability assessment during pharmaceutical
Parameters of purity determination and validation aspects are discussed. Examples of use in pharmaceutical development are
DSC purity determinations have become very popular today . The latest edition of the Mettler software package for thermal analysis, TA72.S GraphWare, now comprises a powerful purity evaluation program. It is based on the simultaneous calculation of the mole ratio of the sum of the eutectic impurities, the melting point of the pure component, the melting point of the substance present and the linearization term. The portion of the melting curve investigated is selected appropriately.
Thermal analysis methods are well-established techniques in research laboratories of pharmaceutical industry. The robustness
and sensitivity of instrumentation, the introduction of automation and of reliable software according to the industrial needs
widened considerably the areas of applications in the last decade. Calibration of instruments and validation of results follow
the state of the art of cGMP as for other analytical techniques. Thermal analysis techniques are especially useful for the
study of the behavior of the poly-phasic systems drug substances and excipients and find a unique place for new delivery systems.
Since change of temperature and moisture occur by processing and storage, changes of the solid state may have a considerable
effect on activity, toxicity and stability of compounds. Current requirements of the International Conference of Harmonisation
for the characterization and the quantitation of polymorphism in new entities re-enforce the position of thermal analysis
techniques. This challenging task needs the use of complementary methods. Combined techniques and microcalorimetry demonstrate
their advantages. This article reviews the current use of thermal analysis and combined techniques in research and development
and in production. The advantage of commercially coupled techniques to thermogravimetry is emphasized with some examples.
Authors:J. FitzPatrick, E. Bond, A. Slemmons, and D. Vieira
Using 1 gram of 241Am from LANL stocks, the purification steps required to obtain a solution of 241Am from the original material are described. Part of the purified solution was submitted for purity analysis by mass spectrometry,
radiochemistry and trace metals analysis. The impurities were expected to be 239Pu and 237Np. A second fraction of this material was used for electroplating three samples onto titanium disks that were suitable for
insertion into an instrument package to be placed into the DANCE detector. The purification methods used, the electroplating
setup and the solutions to various problems that were encountered in making these targets are discussed. The analytical results
are discussed as well as the yields from the electrodeposition process. Comparison of these yields with those from similar
experiments utilizing 235U and 243Am are also discussed.
Authors:Monica Felts de La Roca Soares, José Lamartine Soares-Sobrinho, Keyla Emanuelle Ramos de Silva, Lariza Darlene Santos Alves, Pablo Queiroz Lopes, Lidiane Pinto Correia, Fábio Santos de Souza, Rui Oliveira Macêdo, and Pedro José. Rolim-Neto
quantification/purityanalysis, since the results presented by this technique does not differ significantly from the results presented by the analytic techniques of HPLC and UV–Vis spectrum that are widely used and recognized worldwide.
The DTA curves
Authors:Chen Chen, Fengqin Liu, Jingyang Zhao, Tao Chen, Yulin Li, and Dejun Zhang
collected according to the chromatogram. They were then evaporated under reduced pressure. Residues were dissolved in methanol in preparation for purityanalysis by HPLC.
HPLC Analysis and Identification of Compounds
Authors:Fatema Moni, Suriya Sharmin, Satyajit Roy Rony, Farhana Afroz, Shammi Akhter, and Md. Hossain Sohrab
Esomeprazole and Pantoprazole. Selectivity was further verified by performing peak purityanalysis which was found to be 0.9654 and 0.9065 for Esomeprazole and Pantoprazole, respectively. To ensure the instrument performance, other system suitability parameters
Authors:Y.-F. Yang, X.-Y. Lai, G.-L. Huang, Y.-H. Chen, X.-P. Du, Z.-D. Jiang, F. Chen, and H. Ni
.21 mg 5-HMF were obtained from 150 mg hydrolysate, and the purityanalysis showed that LA and 5-HMF were separated with the purity of 98.72% and 99.18%, respectively. Furthermore, the HPLC analysis showed that LA and 5-HMF were hardly detected in the