Robust and Fast UV\u2013HPLC Method for Biotransformation Analysis of Azecines

Abstract

Dibenzoazecines are a new class of drug candidates for the treatment of schizophrenia. Compared to the drugs currently used in therapy, the azecines have a novel mechanism of action. Thus, they have the potential to cause fewer side effects compared to the standard therapy with a constant high neuroleptic potency. This theory was substantiated by comparative in vivo tests with haloperidol and risperidone. Seventeen new azecine derivatives have already been tested furthermore of stability, physicochemical parameters, pharmacokinetics including esterase cleavage, stability in simulated gastrointestinal fluid, stability at different pH values and determination of octanol/water-partition coefficients. For these substances, class is still a lack of information concerning the metabolism. Therefore, the present study investigated and developed a reliable and reproducible gradient reversed-phase HPLC–UV method to determinate the lead structure LE404 alongside emerging metabolites in compliance with international requirements like ICH guidelines and the European Pharmacopoeia. Up to now, there is no innovative method suitable for such a determination. Chromatographic separations were achieved with a phenomenex™ Gemini column (5 µm C18 110 Å, 250 × 4.60 mm) using a mixture of acetonitrile/potassium dihydrogen phosphate buffer (4 mmol L−1, pH 2.5) as mobile phase. The gradient method flow rate was 1.0 mL min−1, and UV detection was made at 220 nm. The optimized HPLC method was found to be specific, accurate, reproducible and robust for determination of LE404.