Impurities in a lyophilized formulation of BMS-204352: identification and role of sanitizing agents

The purpose of this study was to identify two impurities in the parenteral lyophilized formulation of BMS-204352, investigate the role of sanitizing agents as their potential source, evaluate their effect on drug product stability, and develop a strategy to prevent their contamination of the drug product. The two impurities were identified as o-phenylphenol and 4-t-amylphenol based on liquid chromatography/mass spectroscopy (LC/MS) and chromatographic comparison to authentic samples. The LC/MS spectra of commercially available o-phenylphenol and 4-t-amylphenol showed identical patterns of fragmentation and the same retention times as the impurities identified in the BMS-204352 lyophilized product. Levels of these impurities were low and ranged between 0.2-0.3 microg/vial as determined by HPLC and using an authentic external reference standard. To confirm the hypothesis that the commercial sanitizing agents used in the sterile area were the source of these phenolic impurities, several product samples were spiked with the sanitizing agents. Both o-phenylphenol and 4-t-amylphenol were detected in the spiked samples. Further investigation revealed that o-phenylphenol and 4-t-amylphenol are active ingredients of these commercial sanitizing agents. Drug product samples containing the phenolic impurities showed no potency loss following storage at 30, 50, and 70 degrees C indicating these impurities had no adverse effect on product stability. These studies suggest that sanitizing agents used in the sterile area, although may be present at trace levels below typical cleaning procedure detection methods, need to be properly controlled and closely monitored during the manufacturing of injectable products, particularly highly potent drugs. Sanitizing agents, even though not used on product contact surfaces, may potentially contaminate a product through vapor transfer in an open environment.