Hangzhou Tianlong Pharmaceutical Co., Ltd.

The quality standards for xanthane hydride were established.The xanthane hydride was identified by thin layer chromatog. (TLC), and its purity was determined by HPLC.The TLC spots were clear and specific.The HPLC method results showed that, the degree of the separation between xanthane hydride and the next impurity was >1.5.The precision and repeatability were 0.72% and 1.04%, resp.The loss on drying was less than 3% and the residue on ignition was lower than 0.5%.A quick, easy and accurate method was established and used in the process of oligonucleotides synthesis.

The method for the impurity controlling and content determination of dichloroacetic acid were investigated.By ion chromatog. (IC) for assay of DCAA, IC was carried out using a ion-pac AS23 column (4 mm x 250 mm), mobile phase: 4.5 mmol/L Na₂CO₃/0.8 mmol/L NaHCO₃, suppressed conductivity detector.The standard curve equation of DCAA was Y = 26.01X - 0.5187, (r= 0.9995).DCAA showed a good linearity in 0.004-1 μL/mL, and detection limit was 0.0002 μL/mL.The results indicated that the precision and repeatability were 1.26% and 0.94%, resp., and the anal. recovery was 99.19% (RSD= 1.21%, n= 6).The method for controlling the quality of DCAA is accurate and can be used in the process of oligonucleotide synthesis.

The paper aimed to establish a method for the determination of nilutamide and related impurities in nilutamide active pharmaceutical ingredient(API).HPLC method was adopted.WondaSil C₁₈-WR column was used with mobile phase consisting of acetonitrile-potassium dihydrogen phosphate solution(pH=7.5, gradient elution and isocratic elution), along with a diode array detector(DAD) to control nilutamide and impurity.The detection wavelength was set at 267 nm and 230 nm.The column temperature was 30 °C, and sample amount was 10 μl.The linear range of nilutamide and impurity I were 0.1-1.25 mg/mL(r=0.999 6) and 0.64-6.40 μ g/mL(0.999 9); and the average recoveries were 94.2%(RSD=0.57%, n=2) and 98.6%(RSD=2.1%, n=2).The impurity I was not more than 0.2%, and total impurity was less than 2.0%.The method is rapid, simple, specific, and suitable for the quality control of nilutamide API.