Weak cation-exchange restricted-access material for on-line purification of basic drugs in plasma.
A methylcellulose-immobilized weak cation-exchange (MC-WCX) silica-based restricted-access material (RAM) was developed. The MC-WCX consists of an MC outer surface and 2-carboxyethyl phase internal surface, allowing for direct analysis of basic drugs in plasma. The retention properties of the MC-WCX were evaluated for sulpiride, quinidine, ranitidine, and desipramine. The MC-WCX retained model drugs by cation-exchange, and retained drugs were eluted with the mobile phase containing small amount of acids or salts compared with the MC strong cation-exchanger (MC-SCX). These results indicated the ease of use of the MC-WCX solid-phase extraction (SPE) column when coupled to a reversed-phase analytical column in column-switching high-performance liquid chromatography (HPLC), and various detection principals. Further direct analysis of model drugs in plasma using the MC-WCX SPE column in a column-switching HPLC system successfully performed with sufficient recovery. It is concluded that the MC-WCX is useful for the analysis of basic drugs in plasma.
Sato
Yoshiaki
Y
Analytical Research Laboratories, Eisai Co. Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan. y12-sato@hhc.eisai.co.jp <y12-sato@hhc.eisai.co.jp>
Yamamoto
Eiichi
E
Takakuwa
Susumu
S
Kato
Takashi
T
Asakawa
Naoki
N
D002411:Cation Exchange Resins; D002852:Chromatography, Ion Exchange / Q000379:methods*; D006801:Humans; D004364:Pharmaceutical Preparations / Q000097:blood / Q000302:isolation & purification*; D013056:Spectrophotometry, Ultraviolet
D002411:Cation Exchange Resins; D004364:Pharmaceutical Preparations