Capillary reversed-phase high-performance liquid chromatographic determination of acetyl-methylprednisolone in feline spinal cord

• Published in: Journal of chromatography. B, Biomedical applications Vol. 667; no. 2; pp. 259 - 267
• Main Authors: Lee, Huey G., Huffmon, George V., Becklin, Robert R., Tseng, Jih-Lie, Soble-Smith, Jill, Robertson, James T., Desiderio, Dominic M.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 19.05.1995
• Subjects: Animals; Capillary Action; Cats; Chromatography, High Pressure Liquid - methods; Injections, Spinal; Methylprednisolone - administration & dosage; Methylprednisolone - analogs & derivatives; Methylprednisolone - analysis; Methylprednisolone - pharmacokinetics; Methylprednisolone Acetate; Molecular Structure; Spinal Cord - chemistry; Spinal Cord - metabolism; Spinal Cord Injuries - metabolism
• ISSN: 0378-4347; 1572-6495
• DOI: 10.1016/0378-4347(95)00043-I

Capillary reversed-phase high-performance liquid chromatography (RP-HPLC) was used to determine acetylmethylprednisolone (A-MP) that had been administered to feline spinal cord tissue. The method used a 300 mm × 0.32 mm I.D. packed capillary octadecylsilyl (ODS) column and an isocratic mobile phase of 40 m M triethylamine formate (TEAF, pH 3.2)-acetonitrile (50:50, v:v). The chromatographic behavior of A-MP was evaluated with respect to peak-area and peak-height by varying the A-MP concentration (12–190 μM) with a fixed injection volume (1 μl), and by varying the injection volume (1–10 μl) with a fixed concentration (12 μM) of A-MP. The limit of detection (signal-to-noise ratio, 3:1) was 250 pg (600 fmol) of synthetic A-MP. Various amounts of A-MP directly spiked into feline spinal cord segments were solvent extracted, separated, and plotted against peak-area ( r 2 = 1.00). Background tissue without A-MP gives minimal (<1%) interference at 243 nm. The method also detects exogenous A-MP that was administered into feline spinal cord via an intrathecal injection. Furthermore, the presence of A-MP was confirmed via its molecular ion and corresponding product ions that were obtained by fast-atom bombardment tandem mass spectrometry (FAB-MS-MS).