Shao L K, Locke D C
Chemistry Department, Queens College, CUNY, Flushing 11367, USA.
Anal Chem. 1997 Jun 1;69(11):2008-16. doi: 10.1021/ac961312g.
Baseline separation of 15 taxanes including paclitaxel (Taxol) was achieved on pentafluorophenyl (PFP) HPLC columns. Methods using aqueous acetonitrile gradients on each of two commercial PFP columns were developed that are suitable for the determination of potency, content uniformity, and degradation profile of the paclitaxel bulk drug and injectable dosage form. The elution order is apparently related to molecular size, the number of acetylated hydroxyl groups, and the substitution of a xylosyl group at the 7-position. The resolution of several of the taxanes is a sensitive function of the starting eluent composition and the programming rate, which requires optimization of the methods on both columns. Retention of 10 of the taxanes was studied over the temperature range from 30 to 70 degrees C, and enthalpies of transfer, delta H degree, were determined. Conversion of a hydroxy group to an acetyl group, which can interact more strongly with the fluorines on the PFP, has a large effect on the delta H degree, as does the addition of a xylosyl derivative to the 7-hydroxy. The methods developed for the injectable drug form allow good resolution of the taxanes from the excipient Cremophor EL, a polyethoxylated castor oil used with ethanol to solubilize the paclitaxel. The methods for the bulk drug were fully validated in terms of accuracy, precision, specificity including forced degradation, limits of detection and quantitation, and linearity and range.
在五氟苯基（PFP）高效液相色谱柱上实现了包括紫杉醇（泰素）在内的15种紫杉烷类化合物的基线分离。开发了在两种商用PFP柱上使用乙腈水溶液梯度的方法，这些方法适用于测定紫杉醇原料药和注射剂剂型的效价、含量均匀度和降解情况。洗脱顺序显然与分子大小、乙酰化羟基的数量以及7位木糖基的取代有关。几种紫杉烷类化合物的分离度是起始洗脱液组成和程序升温速率的敏感函数，这需要在两根柱子上对方法进行优化。研究了10种紫杉烷类化合物在30至70摄氏度温度范围内的保留情况，并测定了转移焓（ΔH°）。羟基转化为乙酰基（其可与PFP上的氟更强地相互作用）对ΔH°有很大影响，7位羟基添加木糖基衍生物也是如此。为注射剂剂型开发的方法能够很好地将紫杉烷类化合物与辅料聚氧乙烯蓖麻油（Cremophor EL）分离，聚氧乙烯蓖麻油与乙醇一起用于溶解紫杉醇。原料药的方法在准确性、精密度、特异性（包括强制降解）、检测限和定量限以及线性和范围方面得到了充分验证。
