High-performance liquid chromatographic assay for the determination of the decapeptide cetrorelix, a novel luteinizing hormone-releasing hormone antagonist, in human plasma.
This is the first paper which describes a HPLC method for the determination of the decapeptide cetrorelix, a potent luteinizing hormone-releasing hormone (LH-RH) antagonist, in human plasma by liquid-liquid extraction, concentration by back-extraction with diluted acid into a smaller volume, and fluorescence detection, using the decapeptide D-21740 as internal standard. The excitation (227 nm) and emission wavelengths (340 nm) for cetrorelix and the internal standard are identical. The extraction yield for both peptides is ca. 50% and the assay is linear over the concentration range 2-20 ng/ml in plasma. The mobile phase components are ammonium acetate buffer (0.05 mol/l, pH 4) as solvent A and methanol-acetonitrile (1:1, v/v) as solvent B. The elution condition for the peptides from the column (Lichrospher 60 RP-Select B 5 microns, 250 x 4 mm I.D.) is isocratic with a 49:51 mixture of solvent A-solvent B. The lower limit of quantitation for cetrorelix is 2 ng/ml human plasma.
Department of Biochemistry, ASTA Medica AG, Frankfurt, Germany.
H H
HH
Raffel
M
M
Locher
H O
HO
Borbe
D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors* / Q000097:blood / Q000493:pharmacokinetics; D006801:Humans; D007202:Indicators and Reagents; D007275:Injections, Intravenous; D007279:Injections, Subcutaneous; D008969:Molecular Sequence Data; D012996:Solutions; D013050:Spectrometry, Fluorescence
D007202:Indicators and Reagents; D012996:Solutions; D007987:Gonadotropin-Releasing Hormone; C062876:cetrorelix