title: CE assay for simultaneous determination of charged and neutral impurities in dexamphetamine sulfate using a dual CD system.
abstract: A CE assay for the simultaneous determination of charged and uncharged potential impurities (1S,2S-(+)-norpseudoephedrine, 1R,2S-(-)-norephedrine, phenylacetone and phenylacetone oxime) of dexamphetamine sulfate including the stereoisomer levoamphetamine was developed and validated. The optimized background electrolyte consisted of a 50 mM sodium phosphate buffer, pH 3.0, containing 80 mg/mL sulfobutylether-beta-CD and 25 mg/mL sulfated beta-CD. Separations were performed in 40.2/35 cm, 50 mum id fused-silica capillaries at a temperature of 20 degrees C and an applied voltage of -10 kV. 1R,2S-(-)-ephedrine was used as internal standard. The assay was validated in the range of 0.05-1.0% for the related substances and in the range of 0.05-5.0% for levoamphetamine. The LOD was 0.01-0.02% depending on the analyte. The assay also allowed the separation of the E,Z-stereoisomers of phenylacetone oxime. The effect of the degree of substitution of sulfobutylether-beta-CD was investigated. In commercial samples of dexamphetamine sulfate between 3.2 and 3.7% of levoamphetamine were found. Furthermore, phenylacetone and phenylacetone oxime could be observed at the LOD, indicating the synthetic origin of the investigated samples.
authors.affiliation: Department of Medicinal/Pharmaceutical Chemistry, Friedrich Schiller University Jena, Jena, Germany.
authors.forename: Sudaporn
authors.initials: S
authors.lastname: Wongwan
authors.forename: Bunleu
authors.initials: B
authors.lastname: Sungthong
authors.forename: Gerhard K E
authors.initials: GK
authors.lastname: Scriba
mesh_terms: D000096:Acetone / Q000031:analogs & derivatives / Q000032:analysis / Q000737:chemistry; D000661:Amphetamine / Q000032:analysis / Q000737:chemistry; D002138:Calibration; D003913:Dextroamphetamine / Q000032:analysis* / Q000737:chemistry; D004340:Drug Contamination; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D016014:Linear Models; D010091:Oximes / Q000032:analysis / Q000737:chemistry; D010665:Phenylpropanolamine / Q000032:analysis / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013237:Stereoisomerism; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D010091:Oximes; D047392:beta-Cyclodextrins; C008839:phenylacetone oxime; D000096:Acetone; C093196:SBE4-beta-cyclodextrin; D010665:Phenylpropanolamine; D000661:Amphetamine; C008863:1-phenyl-2-propanone; D003913:Dextroamphetamine