Determination of related substances of levodopa including the R-enantiomer by CE

✍ Scribed by Sudaporn Wongwan; Manuela Hammitzsch-Wiedemann; Gerhard K. E. Scriba

• Book ID: 102184870
• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 205 KB
• Volume: 30
• Category: Article
• ISSN: 0173-0835
• DOI: 10.1002/elps.200900060

✦ Synopsis

Abstract

A CE assay for the simultaneous determination of the impurities of levodopa listed in the European Pharmacopoeia including the (R)‐enantiomer was developed and validated. The analysis was performed in a fused‐silica capillary employing sulfated β‐cyclodextrin as chiral selector at an applied voltage of 20 kV and a temperature of 18°C. The optimized background electrolyte consisted of 0.1 M sodium phosphate buffer, pH 2.0, containing 6 mg/mL sulfated β‐cyclodextrin. L‐phenylalanine was used as the internal standard. The assay was validated in the range of 0.1–1.0% for the impurities at a concentration of levodopa of 2 mg/mL. The effect of different batches of sulfated β‐cyclodextrin was investigated using levodopa and L‐tyrosine as critical pair. The method was applied to determine the purity of several samples of levodopa including the chemical reference substance of the European Pharmacopoeia.