Time-of flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) are probably the most widely used surface analytical techniques beside Auger electron spectroscopy. These techniques were employed to analyse specific spectral features of the adsorbed compounds. Advantages and disadvantages of TOF SIMS and XPS techniques were discussed for a particular problem. The advantage of using TOF-SIMS is in its high resolution to follow specific fragment that is characteristic for a specific molecule. On the other hand, a specific spectral feature were presented in the XPS-excited Auger peak. On that basis a specific finger print connection will be discussed.
B.04 Guest lectureCOBISS.SI-ID: 21771542
Prednisolone, an important active pharmaceutical ingredient, is a synthetic glucocorticoid used for the preparation of various pharmaceutical products with anti-inflammatory and immunosuppressive properties. It is a challenge in high-performance liquid chromatography (HPLC) to separate the prednisolone peak and its structurally related substance (hydrocortisone), which only differs in a double bond at the C-1 position. Successful application of the HPLC method according to the European Pharmacopoeia monograph for related substances of prednisolone is very often limited to the chromatographic system available. This is due to the nonbaseline separation of the prednisolone and hydrocortisone peaks, which is strongly influenced by the instrument parameters and the chosen C18 column. First, an adjusted European Pharmacopoeia method for related substances of prednisolone was developed within the allowable adjustments. Next, an improved stability-indicating reversed-phase HPLC method for related substances of prednisolone was developed and validated for use in quality control laboratories for routine analysis. The optimized separation was performed on a Phenomenex Gemini C18 column (150 mm × 4.6 mm, 3 µm) using a gradient mobile-phase system consisting of acetonitrile/tetrahydrofuran/water (15:10:75 v/v/v), acetonitrile/water (80:20 v/v), and ultraviolet detection at 254 nm. A baseline separation was achieved. A full validation procedure was performed in accordance with International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use guidelines.
F.10 Improvements to an existing technological process or technologyCOBISS.SI-ID: 23091478