Simultaneous Determination of Four Basic Metabolites Formed from Butyrophenone Type Agents by HPLC with Dual Ultraviolet Detection

Abstract

Some basic metabolites of butyrophenone‐type agents are more neurotoxic than the parent compounds. We have developed a high performance liquid chromatography method with dual ultraviolet detection (HPLC‐dual UV method) to quantify simultaneously the four basic metabolites {1,3‐dihydro‐1‐(1,2,3,6‐tetrahydro‐4‐pyridinyl)‐2H‐benzimidazole‐2‐one, (DTP) 1‐phenyl‐1,3,8‐triazaspiro[4.5] decan‐4‐one (PTS), 4‐(4‐chlorophenyl)‐4‐hydroxypiperidine (CPHP), and 4‐(4‐bromophenyl)‐4‐hydroxypiperidine (BPHP)} of droperidol, spiperone, haloperidol, and bromperidol, respectively. DTP, PTS, CPHP, and BPHP were monitored at their UV maxima (278, 247, 220, and 220 nm, respectively) and also at 200 nm. A reversed‐phase (C₁₈) column was eluted with a mixture of acetonitrile‐water‐85% phosphoric acid (80:920:1, v/v/v) at a flow rate of 1.0 mL/min at 25°C. The four basic metabolites were well separated from each other in less than 25 min. The lower limits of detection were 8 to 20 ng/mL with detection at the UV absorption maxima, and 5 to 12 ng/mL with detection at 200 nm. The coefficients of variation for intra‐and inter‐day assays were less than 13.4%. The recoveries were satisfactory. These results confirm that the HPLC‐dual UV method is satisfactory for the simultaneous assay of DTP, PTS, CPHP, and BPHP in phosphate‐buffered saline.

Keywords:

• Butyrophenone‐type agent
• Basic metabolite
• High performance liquid chromatography
• Dual ultraviolet detection