Oil-in-Water Microemulsion High Performance Liquid Chromatographic Analysis of Pharmaceuticals

Efficient and novel oil-in-water microemulsion HPLC separations of a range of solutes have been achieved using isocratic elution and a conventional reversed-phase HPLC column. A single set of isocratic oil-in-water microemulsion HPLC conditions are shown to be successful for the resolution of a wide range of basic, neutral and acidic drugs and excipients. A robust separation method was developed for the quantitative analysis of Naproxen in a tablet formulation. The method offered a similar run time and improved chromatography when compared to conventional HPLC modes, demonstrating its potential for routine use. In developing the separations the effect on the chromatography of varying the operating parameters was studied. While generally the method was robust to changes in some variables, others markedly changed the separation selectivity, solute retention, peak-peak resolution or resulted in poor chromatographic performance. The method was found to be compatible with very low UV working detection wavelengths. As a final stage to the experimental programme, a microemulsion method was developed with the capability of analysing a range of water-insoluble drugs.