Advantages of ultra performance liquid chromatography over high-performance liquid chromatography: comparison of different analytical approaches during analysis of diclofenac gel.

Miniaturization embracing instrumentation, column particle size, and column dimensions is one of the major current trends in separation techniques. This leads to shortening of analysis time and great savings in solvent consumption. Ultra performance liquid chromatography (UPLC) is one of the new developments in liquid chromatography. An ultra-high pressure system allows using of small particle-packed columns with small diameter, which has a positive effect on both system efficiency and analysis time. An analytical method for determination of the active substance diclofenac, the degradation product 1-(2,6-dichlorphenyl)-2-indolinone, and the preservatives methylparaben and propylparaben was used for testing and comparing LC systems. Various octadecylsilica-based analytical columns were examined. Acquity UPLC BEH C18 (2.1 x 50 mm, 1.7 microm) and (2.1 x 100 mm, 1.7 microm) were tested for UPLC. The following analytical columns were used in a test for HPLC: Purospher RP 18e (125 x 4.0 mm, 5 microm), Zorbax Eclipse XDB C18 (75 x 4.6 mm, 3.5 microm), Zorbax Eclipse SB C18 (50 x 4.6 mm, 1.8 microm), as was a monolithic column (Chromolith Performance RP-18e (100 x 4.6 mm). Results of a System Suitability Test (SST) were calculated and compared for each chromatographic peak. System efficiency and analysis duration were compared with regard to solvent consumption and system maintenance