Biosensor for Enantioselective Analysis of S-Cilazapril, S-Trandolapril, and S-Pentopril*

Abstract

The purpose of this research was to construct an amperometric biosensor on L-amino acid oxidase (L-AAOD) supported on a carbon paste for the enantioselective analysis of S-cilazapril (I), S-trandolapril (II), and S-pentopril (III). A chemically modified carbon paste was constructed with L-AAOD. The proposed amperometric biosensor proved reliable for the purity of I, II, and III. The linear working ranges obtained for drug assay were 0.001–100 μmol/l (I), 0.02–10 μmol/l (II), 0.08–50 μmol/l (III) over the pH ranges 7.0–7.4 (I), 6.8–7.4 (II), and 7.0–7.4 (III). The low limits of detection obtained were 5 pmol/l (I), 15 μmol/l (II), and 5 μmol/l (III), respectively. The selectivity of the biosensors was checked by both mixed and separate solution methods. Polyvinylpyrolidone and D-proline did not interfere with the assay of the studied drugs, whereas L-proline presented a potent interfering species. The relative standard deviation values (<0.2%) make the biosensors suitable for direct amperometric assay of these angiotensin-converting enzyme (ACE) inhibitors. The proposed amperometric biosensor that was based on L-AAOD proved reliable in the analysis of the above-mentioned ACE inhibitors and can be used for the quality control of these drugs.

Keywords:

• Angiotensin-converting enzyme inhibitors
• Enantioselective analysis
• Enantioselective biosensor
• S-Cilazapril
• S-Pentopril
• S-Trandolapril