Murnane D, Martin G P, Marriott C
Drug Delivery Research Group, Pharmaceutical Science Research Division, King's College London, Stamford Street, London SE1 9NH, UK.
J Pharm Biomed Anal. 2006 Mar 18;40(5):1149-54. doi: 10.1016/j.jpba.2005.09.028. Epub 2005 Nov 8.
The analysis of weakly basic drugs such as salmeterol xinafoate (SX) by reverse-phase liquid chromatography remains a problem, particularly when present in combination with other drugs such as steroids and weak acids. This study describes the validation of an assay for a weakly basic drug, salmeterol (SB), its weakly acidic counter-ion, 1-hydroxy-2-naphthoic acid (XA), and the neutral glucocorticoid, fluticasone propionate (FP) using a second-generation silica stationary phase (Inertsil ODS-2). The assay utilized an Inertsil ODS-2 base-deactivated 250 mm x 4.6mm, 5 microm HPLC column, with 75:25 methanol:0.6% aqueous ammonium acetate as the mobile phase. Under these near neutral conditions, SB demonstrated a good peak shape (tailing factor=1.21+/-0.02, n=85). The method provided a short analysis time: XA, t(R)=2.96 min; SB, t(R)=5.23 min and FP, t(R)=7.01 min. The assay displayed good sensitivity for both XA (LOD for SX=0.22 microgmL(-1)) and SB (LOD for SX=0.26 microgmL(-1)). The limit of detection for FP was 0.19 microgmL(-1). Neither of the drugs was found to interfere in the determination of the other and the assay accuracy (% recovery) was high (the recoveries were: 99.58+/-1.85% for XA, 99.49+/-1.88% for SB and 100.24+/-1.28% for FP). The assay reproducibility was determined with a mean coefficient of variance for the five calibration concentrations of XA=0.71+/-0.18%; SB=1.11+/-0.64% and FP=0.92+/-0.14%. Analysis of a pressurized metered dose inhaler formulation demonstrated recovery of the analytes that are within pharmacopoeial limits. It was shown that RP-HPLC was suitable for the high throughput analysis of the combination of SX and FP.
采用反相液相色谱法分析诸如昔萘酸沙美特罗（SX）等弱碱性药物仍然存在问题，尤其是当它与其他药物如类固醇和弱酸同时存在时。本研究描述了一种使用第二代硅胶固定相（Inertsil ODS - 2）对弱碱性药物沙美特罗（SB）、其弱酸性抗衡离子1 - 羟基 - 2 - 萘甲酸（XA）以及中性糖皮质激素丙酸氟替卡松（FP）进行含量测定方法的验证。该测定使用了一根Inertsil ODS - 2碱性去活的250 mm×4.6mm、5μm的高效液相色谱柱，以75:25的甲醇:0.6%乙酸铵水溶液作为流动相。在这些接近中性的条件下，SB呈现出良好的峰形（拖尾因子 = 1.21±0.02，n = 85）。该方法提供了较短的分析时间：XA，t(R)=2.96分钟；SB，t(R)=5.23分钟；FP，t(R)=7.01分钟。该测定对XA（SX的检测限 = 0.22μg mL⁻¹）和SB（SX的检测限 = 0.26μg mL⁻¹）均显示出良好的灵敏度。FP的检测限为0.19μg mL⁻¹。未发现任何一种药物对其他药物的测定产生干扰，并且测定准确度（回收率%）很高（回收率分别为：XA为99.58±1.85%，SB为99.49±1.88%，FP为100.24±1.28%）。通过对XA的五个校准浓度计算得出平均变异系数来确定该测定的重现性：XA = 0.71±0.18%；SB = 1.11±0.64%；FP = 0.92±0.14%。对一种压力定量吸入气雾剂制剂的分析表明，分析物的回收率在药典规定的限度内。结果表明，反相高效液相色谱法适用于SX和FP组合的高通量分析。
