[Biotransformation of meclozine in the human body]

After oral administration of 1-[(4-chlorophenyl)-phenylmethyl]-4-[3-methylphenyl)-methyl]-piperazine (1, Meclozine) eleven compounds were isolated from human urine and faeces. The structural elucidation of the metabolites was accomplished by comparison of their spectral data with those of the synthetic reference compounds. The metabolites were identified as: Meclozine (1), N-[(4-chlorophenyl)-phenylmethyl]-piperazine (2), 3-(4-[(4-chlorophenyl)-phenylmethyl]-piperazino)-methyl-benzoic acid (3), 3-(4-[(4-chlorophenyl)-phenylmethyl]-piperazino)-methyl-benzamide] (4), 2-[3-(4-[(4-chlorophenyl)-phenylmethyl]-piperazino)-methyl-benzoyl ]-amino- ethanesulphonic acid (5), 3-(4-[(4-chlorophenyl)-3'-hydroxy-4'-methoxyphenylmethyl]-piper azino)- methyl-benzoic acid (6), 1-[(4-chlorophenyl)-phenylmethyl]-4-[(3-methylphenyl)-methyl]- piperazine-N4-oxide (7), 1-[(4-chlorophenyl)-phenylmethyl]-4-[(3-methylphenyl)-methyl]- piperazine-N,N'-dioxide (8), 3-methyl-benzoic acid (9), 3-methyl-hippuric acid (10) and 3-methyl-benzoic acid-glucuronide (11). The structure of compound 11 was confirmed after enzymatic cleavage and identification of the aglycon. A further metabolite was detected, but not identified.