A new organic hydrophilic monolith stationary phase for HILIC - ELSD topiramate quantification and separation with its main polar impurities in infusion solutions

In this study, a hydrophilic monolith doped with fumed silica nanoparticles was in-situ prepared in a liquid chromatography column. It was clearly demonstrated the addition of silica nanoparticles in the polymerization mixture improved the formation of mesopores in the low size domain (5.2 nm) and thus the specific surface area and hydrophilicity of the monolith. Stability studies showed this monolith was not affected after slightly swelling or shrinking under different solvent conditions. The potential of this new column was exemplified by its capability in hydrophilic interaction liquid chromatography conditions (1) to separate five standard compounds (nucleotides) and (2) to monitor the main degradation products of topiramate an anticonvulsant molecule used primarily to treat epilepsy. For this second separation, the optimum HPLC gradient conditions were determined with only 18 experiments using a computer assisted design of experiments - simplex algorithm software developed in our laboratory. This column was then used successfully for the quantification of the different doses (in mg) of topiramate in a meglumin pharmaceutical formulation. This novel HPLC analytical shows promise as a stability-indicating assay and may be suitable for the quality control of topiramate in pharmaceutical préparations.