ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Determination of curcuminoids in substances and dosage forms by cyclodextrin-mediated capillary electrophoresis with diode array detection

Katarína Maráková, Peter Mikuš, Juraj Piešťanský, and Emil Havránek

Department of Pharmaceutical Analysis and Nuclear Pharmacy, Faculty of Pharmacy, Comenius University, Odbojárov 10, 832 32 Bratislava, Slovakia

E-mail: mikus@fpharm.uniba.sk

Abstract: The present work illustrates the potential of the capillary zone electrophoresis (CZE) separation technique coupled with the on-capillary diode array detector (DAD) for highly reliable determination of curcuminoids (curcumin, CUR, demethoxycurcumin, DCUR, and bisdemethoxycurcumin, BCUR) in substances (commercially available plant extract) and pharmaceutical preparation (commercial pharmaceutical capsules) with minimal sample preparation; (2-hydroxypropyl)-β-cyclodextrin (HP-β-CD) was chosen for an anionic separation of CUR and its structural analogues (DCUR and BCUR) as an appropriate complexing agent (i) providing complete resolution of the curcuminoids and (ii) reducing adsorption of these hydrophobic analytes onto the capillary wall. DAD detection was utilised for characterisation of the composition of the separated zones via differences in the corresponding UV-VIS spectra (scanned at interval of 200–800 nm). Reference and real spectra of the analytes demonstrated that the proposed separation method was sufficiently selective to produce well-separated (i.e. spectrally homogeneous) analyte zones with no interfering compounds present. Successful validation and application of the CZE-DAD method proposed here suggest its routine use in highly effective and reliable analysis of curcuminoids in pharmaceutical samples.

Keywords: capillary zone electrophoresis – diode array detection – curcuminoids – cyclodextrin – pharmaceutical analysis

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-011-0043-0

Chemical Papers 65 (4) 398–405 (2011)