Kunming Jida Pharmaceutical Co. Ltd.

Novel magnetic solid-phase extraction using carboxylated multiwalled carbon nanotubes was proposed with ultra high-performance liquid chromatography–tandem mass spectrometry for the determination of silodosin in biological samples. The effects of various experimental parameters including adsorbent amount, pH, adsorption time, desorption conditions, and adsorbent reusability were systematically validated. Under the optimized conditions, the calibration curve was linear within the concentration range of 1.0–800 ng mL−1 with the correlation coefficient of 0.9997 and the lower limit of detection was 0.3 ng mL−1. The extraction recoveries were over 90.0% with relative standard deviation (RSD) of less than 5.0%. All these results suggested that magnetic extraction method can be used for enrichment and quantification of silodosin in biological samples.

A new HPLC method to determine related substances in risperidone by DAD and peak purity anal. was established, using C₁₈ column (Kromasil, C₁₈, 5 μm, 4.6 × 200 mm), acetonitrile-1% triethylamine buffer (30:70) (adjust pH to 3.0 by phosphoric acid) as mobile phase.The flow rate is 0.8 mL/min, the column oven temperature is 30°, and the detection wavelength is 260 nm.Risperidone and related substances are well separated, and the LOD of raw material 1, intermediate 1, and intermediate 2 was 0.4, 4, 0.4, and 0.6 ng.DAD and peak purity anal. are useful for evaluation of determination of related substances in risperidone by HPLC, and the method is simple, fast, specific and sensitive.

The suitable chromatogram conditions for determination of the content of hydrocortisone sodium succinate for injection by high performance liquid chromatog. were optimized.The suitable chromatogram conditions were as follows: the stationary phase of Kromasil 100-5 C₁₈ column (4.6 × 150 mm, 5 μm) the mobile phase of methanol-phosphate buffer (50:50), the flow rate of 0.5 mL/min and the detection wavelength at 242 nm.The chromatogram conditions could be used for determination of the content of hydrocortisone sodium succinate for inject ion.