A sensitive and specific HPGPC‐FD method for the study of pharmacokinetics and tissue distribution of Radix Ophiopogonis polysaccharide in rats

Interest in antimyocardial ischemic activity of a graminan‐type fructan with a weight average molecular weight of 4.8 kDa extracted from Radix Ophiopogonis (ROP) has necessitated the study of its pharmacokinetics and tissue distribution. For that, a simple HPGPC–FD method was developed for the sensitive and specific determination of FITC‐ROP (fluorescein–isothiocyanate‐labeled ROP) in plasma and rat tissues (heart, liver, spleen, lung, kidney, brain and stomach). The analyte was separated on a Shodex Sugar KS‐802 high‐performance gel column with 0.1 M phosphate buffer (pH 7.0) as mobile phase at a flow rate of 0.5 mL/min, and fluorescence detection at λ_ex 495 nm and λ_em 515 nm. The calibration curve for FITC‐ROP was linear over the range 0.25–20.0 or 50.0 μg/mL in all studied biosamples with correlation coefficients >0.995. The inter‐day and intra‐day precisions of analysis were not more than 10%, and assay accuracy ranged from 93 to 105% for plasma and from 89 to 108% for tissue homogenates. This method has been confirmed here to be suitable for the study of pharmacokinetics and tissue distribution of ROP and the achieved results are highly instructive for the further pharmaceutical development of ROP, suggesting the promising application of the method to the increasingly important carbohydrate‐based drugs. Copyright © 2009 John Wiley & Sons, Ltd.