复方L-18甲基炔诺酮长效注射剂中L-18甲基炔诺酮的RP-HPLC法测定

REVERSED PHASE HIGH PERFORMANCE LIQUIDCHROMATOGRAPHIC DETERMINATION OFLEVONORGESTREL IN LONG ACTING COMPOUNDINJECTION OF LEVONORGESTREL

建立了复方L-18甲基炔诺酮(LNG)长效注射剂中LNG的反相高效液相色谱(RP-HPLC)测定法。采用YWG-C_(18)H_(37)(10μm)柱(150×5mm ΙD),甲醇-水(75:25)流动相,固定波长UV 254 nm检测器,以醋酸可的松为内标。色谱进样前须将注射液用甲醇稀释,并离心除去所析出的甲醇不溶性辅料。本法线性良好(r=0.9999),同次测定平均回收率为99.50±0.59％(n=21),不同次测定为99.94±0·86％(n=15),该混悬注射剂中另一主药雌二醇及各辅料均无干扰。应用本法测定了样品注射液5个批号,结果符合要求。

A simple and reliable RP-HPLC method was established for determining levonorgestrel (LNG) in long acting compound injection,an effective contraceptive pharmaceutics.This aqueous injection contains suspended miorocystals of LNG (5mg/ml) and estradiol (3.5mg/ml),as well as some exoipients.A YWG-C18H37 column,an eluant composed of 75% of methanol and 25% of water and a UV 254nm detector were adapted.Sample injection was diluted with methanol and the excipients diposited were isolated by centrifugation before chromatographic injection.Cortisone acetate (CTA) was used as internal standard.The experimental results exhibited absolutely seperate chromatographic peaks of LNG and CTA,good coefficient of correlation (r=0.999 9) and satisfying average intra-assay recovery of 99.50±0.59% (n=21) and average inter-assay recovery of 99.94±0.86% (n=16).Estradiol and the excipients had no interference.Five batches of this injection were assayed by the method and the contents were 99.79% ~102.86% of the amount labelled.