Spectrophotometric, septrofluorimetric and LC determination of lisinopril

Three methods are described for the determination of lisinopril in the phar maceutical tablets. The spectrophotometric method depends on the reaction o f the lisinopril with sodium hypochlorite and phenyl hydrazine to form a co ndensation product measured at 362 nm. The spectrophotometric method was ex tended to develop a stability indicating method. The spectrophotometric met hod depends on reaction of the lisinopril with o-phthalaldehyde in the pres ence of 2-mercaptoethanol in berate buffer pH 9.5. The fluorescence of the reaction product was measured upon excitation at a maximum of 340 nm with e mission wavelength at 455 nm. The HPLC method depends on using Hypersil sil ica column with a mobile phase consisting of methanol-water-triethylamine ( 50:50:0.1 v/v) and the pH was adjusted to 1.6 with 0.1 N perchloric acid. Q uantitation was achieved with UV detection at 210 nm based on peak area. (C ) 2001 Elsevier Science B.V. All rights reserved.