BACKGROUND: After oral administration dipyrone is rapidly hydrolyzed to 4-methylaminoantipyrine, which is absorbed and further metabolized to 4-formylaminoantipyrine and to 4-aminoantipyrine, which is acetylated by a polymorphic N-acetyltransferase system to 4-acetylaminoantipyrine. To evaluate the presence of dipyrone metabolites in different rat matrices after intraperitoneal administration, an analytical method was developed and validated. METHODOLOGY: The four main dipyrone metabolites were extracted from plasma, cerebrospinal fluid and hypothalamus samples by LLE prior to LC-MS/MS. RESULTS: Standard calibration graphs for all metabolites were linear (r > 0.99). The intra- and inter-day precision and accuracy values were both inferior to 15%. CONCLUSION: This method is simple and specific for studying dipyrone metabolites after intraperitoneal administration.
BACKGROUND: After oral administration dipyrone is rapidly hydrolyzed to 4-methylaminoantipyrine, which is absorbed and further metabolized to 4-formylaminoantipyrine and to 4-aminoantipyrine, which is acetylated by a polymorphic N-acetyltransferase system to 4-acetylaminoantipyrine. To evaluate the presence of dipyrone metabolites in different rat matrices after intraperitoneal administration, an analytical method was developed and validated. METHODOLOGY: The four main dipyrone metabolites were extracted from plasma, cerebrospinal fluid and hypothalamus samples by LLE prior to LC-MS/MS. RESULTS: Standard calibration graphs for all metabolites were linear (r > 0.99). The intra- and inter-day precision and accuracy values were both inferior to 15%. CONCLUSION: This method is simple and specific for studying dipyrone metabolites after intraperitoneal administration.
Authors: David do C Malvar; Fernando A Aguiar; Artur de L L Vaz; Débora C R Assis; Miriam C C de Melo; Valquíria A P Jabor; Evanguedes Kalapothakis; Sérgio H Ferreira; Giuliano C Clososki; Glória E P de Souza Journal: Br J Pharmacol Date: 2014-08 Impact factor: 8.739