title: Evaluation of enantiomeric purity of magnesium-L-aspartate dihydrate.
abstract: Magnesium supplementation in form of organic magnesium salts is a very popular practice. We examined the enantiomeric purity of "Magnesium aspartate dihydrate" monographed in the European Pharmacopeia. A chiral capillary zone electrophoresis using (2-hydroxypropyl)-β-cyclodextrin coupled to laser induced fluorescence detection and a HPLC-fluorescence method with chiral derivatization using o-phthaldialdehyde and N-acetyl-L-cysteine as an orthogonal method were developed and validated. Two batch samples of this substance and three drug products containing the salt were analyzed by means of both methods. The concentration of the D-enantiomer of aspartic acid ranged from 0.03 to 0.12%. Simulations of the synthesis revealed that the d-aspartic acid content is elevated if the dissolution of L-aspartic acid was performed at acidic pH values.
authors.affiliation: University of Würzburg, Institute for Pharmacy and Food Chemistry, Würzburg 97074, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Wahl
authors.affiliation: University of Würzburg, Institute for Pharmacy and Food Chemistry, Würzburg 97074, Germany. Electronic address: u.holzgrabe@pharmazie.uni-wuerzburg.de.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Holzgrabe
mesh_terms: D001224:Aspartic Acid / Q000032:analysis* / Q000138:chemical synthesis; D002851:Chromatography, High Pressure Liquid; D026603:D-Aspartic Acid / Q000032:analysis; D004340:Drug Contamination; D019075:Electrophoresis, Capillary; D006863:Hydrogen-Ion Concentration; D013237:Stereoisomerism
chemical_list: D001224:Aspartic Acid; D026603:D-Aspartic Acid
keywords: Capillary electrophoresis; Chiral separation; Magnesium aspartate; Pharmaceutical analysis; Racemization