INVESTIGADORES
WUILLOUD Rodolfo German
artículos
Título:
Determination of levothyroxine ant its degradation products in pharmaceutical tablets by HPLC-UV-ICP-MS
Autor/es:
KANNAMKUMARATH, SASI S.; WUILLOUD, RODOLFO G.; STALCUP, APRYLL; CARUSO, JOSEPH A.; HIMANSHU, PATEL; SAKR, ADEL
Revista:
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
Editorial:
ROYAL SOCIETY OF CHEMISTRY
Referencias:
Lugar: London; Año: 2004 vol. 19 p. 107 - 113
ISSN:
0267-9477
Resumen:
A new analytical methodology using high-performance liquid chromatography (HPLC) coupled to inductively coupled plasma mass spectrometry (ICP-MS) was applied to study the presence of possible degradation products in levothyroxine tablets. The analytical methodology takes advantage of the element-specific and highly-sensitive I detection provided by ICP-MS and is applied to the speciation of: 3,3?,5,5?-tetraiodothyronine (T4); 3,3?,5-triiodothyronine (T3); 3,5-diiodothyronine (T 2); 3,3?,5,5?-tetraiodothyroacetic acid (TTAA 4); 3,3?,5-triiodothyroacetic acid (TTAA3); and 3,5-diiodothyroacetic acid (TTAA2). Chromatographic conditions were optimized by using UV absorption at 225 nm and ICP-MS detection of 127I. Complete Chromatographic resolution of the levothyroxine degradation products within 25 min was obtained using 22% (v/v) acetonitrile at pH 2.3, adjusted with 0.08% (v/v) trifluoroacetic acid. The introduction of the mobile phase containing acetonitrile was performed by post column on-line dilution (1:3.3) of the Chromatographic eluent with a 2% (v/v) nitric acid solution using a PTFE tee. The separations with either detector were good with little detector effect on the resolution. The peak broadening caused by on-line dilution was insignificant. The detection limits obtained with UV detection ranged from 28.9 to 34.5 ?g I-11, whereas those obtained with the plasma detector were about 175-375 times better (lower). Finally, the analytical methodology was applied to the determination of possible iodine species originated by degradation of T4 in synthetic and commercial levothyroxine sodium tablets.