Bioanalysis and pharmacokinetics of chitosan ester in rabbit serum by HPLC with postcolumn fluorescence derivatization

Interest in antiatherosclerotic activity of chitosan ester (PS916) with a new form of sulfate amino polysaccharide derived from marine chitin has necessitated the development of a sensitive and specific method to study its pharmacokinetics. A sensitive and reproducible high-performance liquid chromatography (HPLC) with postcolumn fluorescence derivatization method was developed and validated for the determination of PS916 in rabbit serum. Chromatography was carried out using a C8 reversed-phase column with an isocratic mobile phase consisting of methanol–water (20:80, v/v) at a flow rate of 0.2 ml/min. The derivatization procedure involved postcolumn reaction with guanidine hydrochloride in an alkaline medium at 110 °C. The fluorometric detector was operated at 250 nm (excitation) and 435 nm (emission). The assay was linear over the concentration range of 5–100 μg/ml. The lower limit of detection (LLOD) was found to be 1.0 μg/ml. The proposed method was successfully applied for a pharmacokinetic study of PS916 in rabbits.