Head-column field-amplified sample stacking in capillary electrophoresis for the determination of cimetidine, famotidine, nizatidine, and ranitidine-HCl in plasma.
In this study, low concentrations of histamine2-receptor (H2-)antagonists were effected across a water plug, with separation taking place in a binary buffer comprising ethylene glycol and NaH2PO4 (pH 5.0), and detection at 214 nm. Liquid-liquid extraction with ethyl acetate- isopropanol is shown to provide extracts that are sufficiently clean. The calibration curves were linear over a concentration range of 0.1-2.00 microg/mL cimetidine, 0.2-5.0 microg/mL ranitidine-HCl, 0.3-5.0 microg/mL nizatidine, and 0.1-3.0 microg/mL famotidine. Mean recoveries were > 82%, while the intra- and interday relative standard deviations (RSDs) and relative errors (REs) were all < 13%. The method is sensitive with a detection limit of 3 ng/mL cimetidine, 30 ng/mL ranitidine HCl, 50 ng/mL nizatidine and 10 ng/mL famotidine (S/N = 3, electric-driven injection 90 s). This newly developed capillary electrophoresis (CE) method was applied for the determination of analytes extracted from plasma taken from a volunteer dosing a cimetidine, ranitidine, and nizatidine tablet simultaneously. These three H2-antagonists can be detected in real samples by this method, excluding the low dosing of famotidine tablet.
Wu
S M
SM
School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Taiwan. shmewu@kmu.edu.tw
Ho
Y H
YH
Wu
H L
HL
Chen
S H
SH
Ko
H S
HS
D002021:Buffers; D002927:Cimetidine / Q000097:blood*; D004553:Electric Conductivity; D019075:Electrophoresis, Capillary / Q000379:methods* / Q000592:standards; D019855:Ethylene Glycol; D015738:Famotidine / Q000097:blood*; D006635:Histamine H2 Antagonists / Q000097:blood*; D006801:Humans; D016567:Nizatidine / Q000097:blood*; D010710:Phosphates; D011899:Ranitidine / Q000097:blood*; D012680:Sensitivity and Specificity; D013997:Time Factors; D014867:Water
D002021:Buffers; D006635:Histamine H2 Antagonists; D010710:Phosphates; D014867:Water; D015738:Famotidine; D002927:Cimetidine; D011899:Ranitidine; D019855:Ethylene Glycol; D016567:Nizatidine