Simultaneous determination of chondroitin sulfate sodium, allantoin and pyridoxine hydrochloride in pharmaceutical eye drops by an ion-pair high-performance liquid chromatography

An ion-pair high-performance liquid chromatography (HPLC) method has been developed for the simultaneous determination of chondroitin sulfate sodium (CSS), allantoin and pyridoxine hydrochloride (VB6) in a commercial eye drops dosage form. An Alltima C18 column (250 mm × 4.6 mm i.d., 5 μm) was used for the separation at room temperature, with 25 mM ammonium dihydrogen phosphate (containing 0.01% heptanesulfonic acid sodium salt) and acetonitrile (95:5, v/v) as the mobile phase at the flow rate of 0.5 mL min−1. The detection wavelength for CSS, allantoin and VB6 was 195 nm, 215 nm and 291 nm, respectively. The method showed good linearity for CSS, allantoin and VB6, with correlation coefficients greater than 0.9996, in the range of 203.96–815.84 mg L−1, 371.16–1488.64 mg L−1, and 23.32–93.28 mg L−1, respectively. The instrumental and method precisions were adequate with all relative standard deviations lower than 2.0%. The accuracy of this method, measured by the recovery of three compounds from spiked placebo solutions, was from 99.01% to 101.92%. The three components, CSS, allantoin and VB6 were well separated from other ingredients and degradation products. This method is fast, simple, and can be used for direct and simultaneous determination of CSS, allantoin and VB6 in the pharmaceutical preparation.