Determination of Related Substance in Indometacin Enteric-coated Tablet by Improving HPLC / 中国药房

ABSTRACT

OBJECTIVE:To improve HPLC for the contents determination of 2-methyl-5-methoxy-indole-3-acetic acid(impuri-ty Ⅰ) and 4-chlorobenzoic (impurity Ⅱ) in Indometacin enteric-coated tablet. METHODS:The column was Phenomenex Phe-nyl-Hexyl with mobile phase of 10 g/L acetic acid solution- acetonitrile(gradient elution)at a flow rate of 1.0 ml/min,the detec-tion wavelength was 254 nm,column temperature was 40℃,injection volume was 20 μl. RESULTS:The linear range was 0.262 2-5.243 0 μg/ml for impurity Ⅰ(r=0.999 8)and 0.252 5-5.050 0 μg/ml for impurity Ⅱ(r=0.999 8);the limits of quanti-tation were 1.12 ng and 0.48 ng,limits of detection were 0.340 ng and 0.146 ng,respectively;RSDs of precision,stability and re-producibility tests were lower than 2%;recoveries were 99.71%-100.52%(RSD=0.28%,n=9) and 100.84%-102.14%(RSD=0.47%,n=9). CONCLUSIONS:The method is accurate and rapid,and can be used for the contents determination of impurity Ⅰand impurityⅡin Indometacin enteric-coated tablet.