Determination of a new bisphosphonate, YM175, in plasma, urine and bone by high-performance liquid chromatography with electrochemical detection.
A high-performance liquid chromatographic method for the determination of disodium dihydrogen(cycloheptylamino)methylene-bisphosphonate monohydrate (YM175) in plasma, urine and bone is described. Plasma obtained in high-dose animal studies is pretreated by Method A, a simple method using 1 ml of plasma, which is based on deproteinization of plasma followed by coprecipitation of the drug with calcium phosphate and removal of excess calcium ions by AG 50W-X8 resin. Plasma obtained in lower-dose clinical studies is treated by Method B, a more sensitive method using 10 ml of plasma, which is based on solid-phase extraction using a Sep-Pak C18 cartridge coupled with Method A. Urine and bone are treated similarly to Method B. The chromatographic system consists of a mobile phase at pH 11, an alkali-stable column and an electrochemical detector operating in the oxidation mode. The determination limit is 5 ng/ml for Method A and 0.5 ng/ml for Method B in plasma, 1 ng/ml in urine, and 25 ng/g in bone.
Usui
T
T
Drug Metabolism Department, Yamanouchi Pharmaceutical Co., Ltd., Tokyo, Japan.
Watanabe
T
T
Higuchi
S
S
D000818:Animals; D001842:Bone and Bones / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004164:Diphosphonates / Q000032:analysis* / Q000097:blood / Q000652:urine; D004285:Dogs; D004563:Electrochemistry; D006801:Humans; D051381:Rats; D015203:Reproducibility of Results
D004164:Diphosphonates; C071542:cimadronate