title: CE as orthogonal technique to HPLC for alprazolam degradation product identification.
abstract: The control of degradation products is currently a critical issue to the pharmaceutical industry. A degradation product that appeared in alprazolam tablets during their stability assay, 7-chloro-1-methyl-5-phenyl-[1,2,4]triazolo[4,3-a]quinolin-4-amine, also named triazolaminoquinoline, was tested as possible candidate in the HPLC method employed for the study. The impurity showed the same retention time and spectra as the degradation product; but as all these compounds are very closely related, a confirmation with an independent technique was necessary, and CE was chosen for that purpose. Problems related to the adsorption of the analytes to the negatively charged silica surface were solved by employing a new polymeric capillary coating consisting of poly(3-aminopropylmethylsiloxane). The polymer provided EOF towards the anode, and the two compounds were separated in less than 8 min in a 60 cm total-length capillary, 75 microm id capillary with a BGE containing 50 mM phosphate buffer at pH 2.0 with 20% ACN. When the sample containing the degradation product was injected, the presence of triazolaminoquinoline was confirmed.
authors.affiliation: Sección de Química Analítica, Facultad de Farmacia, Universidad San Pablo-CEU, Campus Montepríncipe, Madrid, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Saavedra
authors.forename: Angel Luis
authors.initials: AL
authors.lastname: Huidobro
authors.forename: Antonia
authors.initials: A
authors.lastname: García
authors.forename: Jose Carlos
authors.initials: JC
authors.lastname: Cabanelas
authors.forename: María G
authors.initials: MG
authors.lastname: González
authors.forename: Coral
authors.initials: C
authors.lastname: Barbas
mesh_terms: D000525:Alprazolam / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D004340:Drug Contamination; D019075:Electrophoresis, Capillary; D011804:Quinolines / Q000032:analysis*; D012833:Siloxanes / Q000737:chemistry
chemical_list: D011804:Quinolines; D012833:Siloxanes; C513347:poly(3-aminopropylmethylsiloxane); C465922:triazolaminoquinoleine; D000525:Alprazolam