ABSTRACT
Objective To build an identification method for Norvascand its counterfeit drugs based on the differences of their pharmaceutical excipients with the original and generic Amlodipine besylatetablets as tools .Methods Raman spectra of pharmaceutical excipients which were usually used in tablets were collected .Similarity algorithm and characteristic Raman bands were used to search the excipients contained in the tablets .If the excipients was not the same as excipients contained in Nor-vasc ,the tablet was judged as counterfeit drugs .Otherwise ,principal component analysis was used to identify counterfeit and generic .Results and conclusion The method based on Raman spectra of pharmaceutical excipients could identify Norvasc and counterfeit drugs efficiently and accurately .