Aim of this work was to set up a method for the sensitive and selective determination of nitrite (NO2-) and total N-nitroso groups (TNG) in dalteparin and nadroparin, commercial low- molecular-weight heparins (LMWH), prepared by deaminative depolymerization of heparin with nitrous acid. The European Pharmacopoeia VI ed. indicates respectively 5 ppm as the maximum content for contaminant NO2- in the former and 0.25 ppm for TNG in the latter and no clear indication is given for N-NO groups in dalteparin, i.e. TNG must be absent because of the specific manufacturing process. The proposed technique is based on the development of a pre-analytical device, coupled to a chemiluminometer, constituted by three sequentially connected and commercially available purge vessels, where selective reagents are employed for the conversion of NO2- and N-NO to nitric oxide (NO). In detail, NO2- was determined in the first chamber and non-volatile and volatile TNG in the second and third. This method was validated for selectivity, sensitivity, linearity, accuracy and precision. The method was shown to be selective, with a quantitative linear range of 1-1000 ppb). The bias, intra- and inter-day percent relative error was lower than 1%. The contamination of NO2- and TNG in nadreparin was below the limits; for dalteparin NO2- fell within the limit, but there was a huge amount of TNG (15.80 ± 0.05 ppm-6.69 ± 0.02 ppm). Preliminary investigation on the solvent-extractable material from dalteparin showed the majority of chemiluminescence retained in the aqueous residue to indicate that this N-NO groups may belong to solvent unextractable material or be tightly bound to the dalteparin backbone.
A simplified screening procedure for determination of total N-NO groups (TNG) and nitrite (NO2-) in commercial low-molecular-weight heparins (LMWH) by selective chemical denitrosation followed by high-sensitivity chemiluminescence detection (NO-analyzer, NOA) / G. Beretta, F. Gelmini, M. Merlino, S. Furlanetto, R. Maffei Facino. - In: JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS. - ISSN 0731-7085. - 49:5(2009), pp. 1179-1184.
|Titolo:||A simplified screening procedure for determination of total N-NO groups (TNG) and nitrite (NO2-) in commercial low-molecular-weight heparins (LMWH) by selective chemical denitrosation followed by high-sensitivity chemiluminescence detection (NO-analyzer, NOA)|
BERETTA, GIANGIACOMO (Primo)
GELMINI, FABRIZIO (Secondo)
MAFFEI FACINO, ROBERTO (Ultimo)
|Settore Scientifico Disciplinare:||Settore CHIM/08 - Chimica Farmaceutica|
Settore CHIM/01 - Chimica Analitica
|Data di pubblicazione:||2009|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/j.jpba.2009.02.029|
|Appare nelle tipologie:||01 - Articolo su periodico|