Identification of antihypertensive combination tablets using ultra-high-speed liquid chromatography-photodiode array detection

The section of liquid chromatography in "General Tests, Processes, and Apparatus" has been revised in The Japanese Pharmacopoeia, Sixteenth Edition. In the case of using photodiode array detection (PDA), a new comment was added such that highly specific identification can be achieved by confirming the identity of the chemical structure of the component and that of an authentic specimen, in addition to the identity of their retention times. Thus, in this paper we describe a rapid and effective identification and quantification of the components of some combination tablets using the PDA detector. In the case of the ECARD® combination tablet, which contains Candesartan cilexetil and Hydrochlorothiazide, the analysis time was 15 min using conventional HPLC. The analysis time was cut down to under 2.5 min by using ultra-high-speed liquid chromatography (ultra-high-speed LC). In addition, the separated peaks that were detected by PDA detector exhibited the same spectra as those measured by a UV-VIS detector. Therefore, rapid and effective identification and quantification could be carried out by using the ultra-high-speed LC-PDA detector system. We think that the present system is of use for the analysis of various combination drugs and multi-component systems.