Quantitative analysis of natural cyclodextrins by high-performance liquid chromatography with pulsed amperometric detection: Application to cell permeation study

Simple HPLC-PAD methods were developed for quantitation of cyclodextrins (CDs) in aqueous matrices from in vitro cell permeation studies. C-18 solid-phase extraction was used for sample pretreatment. Samples were analysed using acetonitrile–water mobile phase with post-column alkalization by 0.5 M NaOH. Zorbax SB-Aq (for α-CD) and Zorbax SB-Phenyl (for β-CD and γ-CD) columns gave excellent peak shape and sufficient resolution of CD to glucose (2.7–3.2). The methods showed good concentration–response relationship (r ≥ 0.999), precision (RSD% 0.7–5.1), repeatability (RSD% 3.4–13.7) and accuracy (87–107%). The limits of quantitation were 0.78, 0.46 and 0.52 μg/ml for α-CD, β-CD and γ-CD (RSD% of 10.6, 8.1 and 16.3, respectively).