Atemnkeng Magnus A, Marchand Els, Plaizier-Vercammen Jacqueline
Vrije Universiteit Brussel, Department of Pharmaceutical Technology and Physical Pharmacy, Laarbeeklaan 103, B-1090 Brussels, Belgium.
J Pharm Biomed Anal. 2007 Jan 17;43(2):727-32. doi: 10.1016/j.jpba.2006.07.053. Epub 2006 Oct 30.
Two HPLC-UV methods are described for the separate determination of artemether (AM) and the combined preservatives, methylparaben and propylparaben in a pharmaceutical dosage form. These analytes are contained in a dry suspension with a high amount of non-soluble excipients, some of which can interfere with the analysis. This makes their separation and analysis of the actives complex. Moreover, due to the wide difference in concentrations, the three analytes could not be quantitated simultaneously. Artemether was analysed using a reversed-phase Nucleosil C(18) column [5 microm, 125 mm x 4 mm (i.d.)] with a mixture of acetonitrile: potassium phosphate buffer pH 5.0 (0.05 M): water [48:32:10 (v/v/v)] as mobile phase. Due to the low solubility of the hydroxy benzoic acid esters in water, their sodium salts were used in the formulation. Complete separation of these preservatives was achieved on the same type of column as artemether using as eluent acetonitrile: potassium phosphate buffer pH 5.0 (0.05 M) (30:70, v/v). Quantitation was achieved with UV detection at 215 nm for artemether and 254 nm for the parabens, respectively. And in both methods, pump flow rate was 1.0 ml/min, sample injection volume 20 microl, ambient temperature maintained and no prior sample extraction methods were necessary throughout the experiments. Calibration curves were linear at concentration ranges of 4-16 microg/ml, 1-4 microg/ml and 1-10 mg/ml for methylparaben, propylparaben and artemether respectively. The excipient powder interference could be eliminated by diluting the sample and the analytes eluted at relatively short times using these systems. Both methods were further validated in terms of specificity, linearity, precision and accuracy. The procedures prescribed here are simple, selective and can be used for routine quality control and stability indicating tests involving the analysed compounds formulated in complex matrices.
本文描述了两种高效液相色谱 - 紫外检测法，用于分别测定药物剂型中蒿甲醚（AM）以及防腐剂甲基对羟基苯甲酸酯和丙基对羟基苯甲酸酯。这些分析物存在于含有大量不溶性辅料的干混悬剂中，其中一些辅料会干扰分析。这使得活性成分的分离和分析变得复杂。此外，由于浓度差异较大，这三种分析物无法同时进行定量分析。蒿甲醚采用反相Nucleosil C(18) 柱 [5微米，125毫米×4毫米（内径）] 进行分析，以乙腈：pH 5.0的磷酸钾缓冲液（0.05 M）：水 [48:32:10（v/v/v）] 的混合物作为流动相。由于羟基苯甲酸酯在水中的溶解度较低，其钠盐被用于制剂中。使用与蒿甲醚相同类型的色谱柱，以乙腈：pH 5.0的磷酸钾缓冲液（0.05 M）（30:70，v/v）作为洗脱剂，实现了这些防腐剂的完全分离。分别在215纳米处对蒿甲醚进行紫外检测以及在254纳米处对尼泊金酯进行紫外检测来实现定量分析。在这两种方法中，泵流速均为1.0毫升/分钟；进样体积为20微升；保持环境温度，并且在整个实验过程中无需预先进行样品提取方法。甲基对羟基苯甲酸酯、丙基对羟基苯甲酸酯和蒿甲醚的校准曲线在浓度范围分别为4 - 16微克/毫升、1 - 4微克/毫升和1 - 10毫克/毫升时呈线性。通过稀释样品可消除辅料粉末的干扰，并且使用这些系统，分析物在相对较短的时间内洗脱。两种方法在特异性、线性、精密度和准确度方面均进一步得到验证。此处规定的方法简单、具有选择性，可用于常规质量控制以及涉及复杂基质中所分析化合物的稳定性指示试验。
