Finger printing of counterfeit bevacizumab and identifying it before clinical use.

ABSTRACT

BACKGROUND: Bevacizumab is widely used for ophthalmic purposes. Recently, counterfeit bevacizumab has become a matter of concern. We analysed samples of suspected counterfeit formulations of bevacizumab and assessed the possibility of using simple tests in the clinic by ophthalmologists to prevent the use of counterfeit preparations in patients. METHODS: We did a protein analysis using Bradford assay and SDS-PAGE to confirm the presence of bevacizumab in 16 samples - 6 suspected and 10 others. The samples were also subjected to physicochemical analysis such as osmolarity, chloride content and pH. The samples tested negative for protein were analysed by mass spectrometry to detect drugs used in place of bevacizumab. We standardized the method of frothing and precipitation analysis for identifying authentic samples of bevacizumab before their clinical use. RESULTS: Five of the 16 samples tested were negative for the presence of bevacizumab. The physicochemical parameters also supported the protein analysis test. However, no ionizable organic compound (other drug[s]) was detected by mass spectrometry. CONCLUSION: Ophthalmic use of counterfeit bevacizumab can be prevented by simple methods such as the frothing and precipitation tests. These can identify the absence of an active drug.