High Performance Liquid Chromatographic Analysis of Pharmaceuticals Using Oil-In-Water Microemulsion Eluent and Monolithic Column

摘要

Novel and efficient separations of pharmaceutical substances were achieved using oil-in-water microemulsion eluent and a conventional C18 packing with a flow rate of 1 mL/min−1. Attempts to decrease analysis time was limited due to the high viscosity of the microemulsion which generated relatively high back-pressures. Monolithic columns gave 3-fold lower back-pressures and allowed flow rates of 4 mL/min−1. with the same microemulsion mobile phase which permitted rapid separations to be achieved. Separation of a test-mix of paraben preservatives was achieved in both isocratic and gradient mode in less than 1 min. The monolith-microemulsion combination was applied to rapidly quantitatively analyse two formulated products with excellent linearity, accuracy and repeatability. Quantitative analysis times were under 90 seconds. Successful quantitation of both nicotine lozenges and naprosyn tablets was performed using this approach.