Development of a Method for the Determination of Pyrimethamine Concentrations in Feeds by Ion-Pairing High-Performance Liquid Chromatography

Abstract

An ion-pairing reversed-phase high-performance liquid chromatography (HPLC) method with diode array detection at 280 nm was developed to determine pyrimethamine concentrations in feed for laying hens. Pyrimethamine was extracted with a mixture of 5% isobutanol and 95% benzene, and the extract was cleaned up on an alumina column. The drug was eluted from an Intersil ODS-3V column (250 by 4.6 mm) with a mixture of 25% acetonitrile and 75% water (vol/vol) containing 0.01 M tetramethylammonium chloride as an ion-pairing agent and adjusted with acetic acid to pH 3.5. The flow rate was 1.0 ml/min. Mean recovery of pyrimethamine from supplemented feeds at concentrations of 2, 4, and 5 microg/g of feed were 100.5, 103.5, and 100.8%, respectively. Precision within a day ranged from 4.3 to 7.0% for the three concentrations, and day-to-day precision was 5.3% for feed supplemented at a concentration of 4 microg/g. No chromatographic interference was detected from other 2,4-diaminopyrimidine compounds or other major drugs used in poultry.

Investigation of antimalarial drug pyrimethamine and its interaction with dsDNA by electrochemical and spectroscopic techniques

“…linear dynamic ranges for PMT are comparable or even better than those obtained in several previous studies. [62][63][64] This method, being fast, simple, sensitive, selective and cost effective, is used for recognition and evaluation of PMT. The precision of the method was evaluated by repeating the experiments on the same days (within day reproducibility) with different standard solutions (freshly prepared at the same concentration).…”

Simultaneous determination of pyrimethamine, sulfadoxine, mefloquine, and ibuprofen in pharmaceutical formulations by RP-HPLC

“…In some cases gastrointestinal hemorrhage and dyspepsia are reported. Hypersensitivity reactions occur occasionally, including skin rash, which can be controlled upon immediate withdrawal of therapy (British Pharmacopoeia, 2003;Merck, 2001;Martindale and Westcott, 1996) A number of methods have been reported by various authors for the determination of mefloquine (Lamant et al, 1988;Bergqvist et al, 1988Bergqvist et al, , 1991Bergqvist et al, , 1993Bergqvist et al, , 1994Karbwang et al, 1989;Qiu et al, 1992;Souri et al, 1997;Green et al, 1999), pyrimethamine (Timm and Weidekamm, 1982;Bergqvist et al, 1991;Eljaschewitsch et al, 1996;Bangchang et al, 1997;Astier et al, 1997;Liboux et al, 1991;Zytkovicz et al, 1991;Tracqui et al, 1993;Roberts et al, 1995;Gong et al, 2002;Lin and Jeng, 2002), sulfadoxine (Bhoir et al, 2001;Bonini et al, 1981), and ibuprofen (Sochor et al, 1994(Sochor et al, , 1995Lemko et al, 1993;Castillo and Smith 1993;Rifai et al, 1996;Save et al, 1997;Kepp et al, 1997;Bhushan and Martens, 1998;Kang et al, 1998;Ducret et al, 1998;Gasco-Lopez et al, 1999;Canaparo et al, 2000;Vermeulen and Remon, 2000;…”