| A Thin Layer Chromatography Method to Identify Oxaliplatin in Aqueous Solution Norma Hernandez-Trejoa, Anja Hampeb, and Rainer Helmut Müllera Department of Pharmaceutical Technology, Biotechnology & Quality Management, Free University of Berlina, Berlin (Germany), and Pharmasol GmbHb, Berlin (Germany)
Within the preparation process of medicines in pharmacies - in addition to having a recognized analytical certificate -the identity of the drug needs to be confirmed. Ideally this should be done in a non-destructive way that the packaged drug can subsequently still be used for the medicine preparation. To achieve this, a new thin layer chromatography (TLC) method to identify oxaliplatin (CAS 61825-94-3) was developed. This method can be used during the quality assurance of oxaliplatin preparations for infusion. The method offers the possibility of directly using an aqueous prepara-tion of oxaliplatin instead of an additional sample preparation involving the weighing of the drug powder. The main advantage when using aqueous oxaliplatin solutions is the reduction of the occupational risk for the pharmacist when handling hazardous drugs, and the protection of the sterility of the drug powder solution before the administration of the preparations. In the present method a Silica 60 F254 aluminium sheet is used as a stationary phase and a quaternary mobile phase consisting of methanol-tetrahydrofuran-triethylamine-water (20:2:0.5:1.25 v/v). After a development of 8 cm in a presaturated chamber, the chromatography layer is dried, followed by visual inspection under a ultraviolet lamp at 254 nm. Oxaliplatin spots can be detected with a retention factor (rf) of ~ 0.7, also after chemical derivatization with specific reagents. The Especification of the method is based on the rf comparison of the oxaliplatin spots obtained for a test and a reference solution. Additionally, if the intensity of the sample spot lies between the colour and the intensity of the reference solution spot, the drug should be identified as oxaliplatin. The selectivity and the intermediate precision of the method were investigated in this study. The first was achieved by comparing oxaliplatin with potential impurities and ref-erence substances, described in the current monograph of the European Pharmacopoeia. After the analysis of a test batch of oxaliplatin by two different analysts, no significant differences were observed after statistical comparison of means and variances.
Key words Identification method • Oxaliplatin • Thin layer chromatography |
