Process for making S(-) Amlodipine salts

Abstract

A process for the preparation of S(−) Amlodipine salts which comprises reaction of S(−)Amlodipine base with a solution of pharmaceutically acceptable acid such as benzene sulfonic acid, oxalic acid, maleic acid, succinic acid and p-toluene sulfonic acid. The reaction is carried out in the presence of an organic solvent at room temperature. The organic solvents include alcohols like ethanol methanol 2 propanol hydrocarbons like toluene and polar solvent like dimethyl sulfoxide. The salt is obtained by addition of water and isolation of the salt formed by filtration. The unique feature of the invention is production of S(−) Amlodipine besylate in good chemical yield, high enantiomeric purity and with the quality required for preparation of pharmaceutical composition i.e. tablet formulation.

Dependencies are inferred from the claim text.