Strode J T, Taylor L T, Howard A L, Ip D, Brooks M A
Department of Chemistry, Virginia Polytechnic Institute, Blacksburg, VA 24061.
J Pharm Biomed Anal. 1994 Aug;12(8):1003-14. doi: 10.1016/0731-7085(94)00048-4.
A reproducible and selective supercritical fluid chromatography (SFC) method was developed for the analysis of felodipine, a drug indicated for the treatment of hypertension. Methanol-modified carbon dioxide was employed as the SFC mobile phase with both electron capture detection (ECD) and multi-wavelength detection (MWD) being used simultaneously for analyte determination. Chromatography limit of detection (LOD) and limit of quantitation (LOQ), linear dynamic range (LDR) and injection precision were obtained in order to assess chromatographic and detector performance for both the SFC/MWD and SFC/ECD/MWD systems. The method was shown to be stability indicating since felodipine could be separated from its potential oxidative degradation product, H152/37, in under 6 min (felodipine k' = 2.44). Sample throughput was increased by 60% with the SFC assay vs LC. The optimized SFC method was shown to be equivalent to an existing LC/UV procedure for the analysis of a sustained-release tablet while realizing a 92% saving in disposable solvent waste. In order to achieve further solvent savings overall, supercritical fluid extraction (SFE) with 8% methanol-modified carbon dioxide as the extraction fluid was used to extract felodipine from a sustained-release tablet (as opposed to traditional solvent extraction). Comparable drug recoveries were obtained with SFE sample preparation technique when either SFC or LC extract analysis was utilized.
开发了一种可重现且具有选择性的超临界流体色谱法（SFC），用于分析非洛地平，一种用于治疗高血压的药物。以甲醇改性的二氧化碳作为SFC流动相，同时使用电子捕获检测（ECD）和多波长检测（MWD）来测定分析物。获得了色谱检测限（LOD）和定量限（LOQ）、线性动态范围（LDR）和进样精密度，以评估SFC/MWD和SFC/ECD/MWD系统的色谱和检测器性能。该方法显示出稳定性指示能力，因为非洛地平能够在6分钟内与其潜在的氧化降解产物H152/37分离（非洛地平k' = 2.44）。与液相色谱（LC）相比，SFC测定法的样品通量提高了60%。经优化的SFC方法在分析缓释片时被证明与现有的LC/UV方法等效，同时可减少92%的一次性溶剂浪费。为了进一步总体节省溶剂，使用以8%甲醇改性二氧化碳为萃取液的超临界流体萃取（SFE）从缓释片中萃取非洛地平（与传统溶剂萃取相反）。当采用SFC或LC提取物分析时，使用SFE样品制备技术可获得相当的药物回收率。
