Determination of impurities in an acidic drug substance by micellar electrokinetic chromatography

Abstract

SummaryA sensitive micellar electrokinetic chromatography method for the determination of impurities in SB-209247, a novel LTB4 antagonist, has been developed. Selectivity was optimised by systematic examination of the effects of the acetonitrile content in the separation buffer. Sensitivity and resolution was enhanced by focusing effects for both charged and neutral analytes achieved by a special sample buffer composition. Minor impurities well below 0.1% peak area ratio can be readily and reliably detected. The validity of the method has been successfully demonstrated with respect to reproducibility of peak area ratios and the linearity of a key impurity. A comparison with HPLC has shown the method has complementary selectivity and competitive sensitivity.

Impurity analysis of pharmaceuticals using capillary electromigration methods

“…The method was able to detect the impurities below 0.1% of the peak area of the main analyte. LOD and LOQ data of MEKC and HPLC were comparable [135].…”

“…In Fig. 10, a chromatogram of SB-209247 and seven impurities are depicted [135]. The method was able to detect the impurities below 0.1% of the peak area of the main analyte.…”

Determination of organic impurities in pharmaceutical preparations

“…is used for the determination of the neutral components of a sample [163][164][165]. Micelles are formed on the addition of surfactants to a buffer solution at concentrations exceeding the critical micelle concentration.…”

Focus. Dealing with ‘real’ samples: sample pre-treatment in microfluidic systems

“…One such technique is termed sweeping. Sweeping, initially observed by Gilges 50 and further developed by Quirino, 51,52 is defined as the picking and accumulating of neutral analyte molecules by pseudostationary phases (e.g. sodium dodecyl sulfate) that enter and fill the sample zone upon application of a voltage.…”