IMPORTANCE: Bevacizumab acquired from compounding pharmacies for intravitreal injection may cause infectious and noninfectious inflammation. In addition to safety issues, the drug itself may have variable efficacy associated with product aliquoting, handling, and distribution. OBJECTIVE: To conduct surveillance cultures, evaluate endotoxin levels, and assess protein concentrations of bevacizumab obtained from compounding pharmacies in the United States. DESIGN AND SETTING: Prospective in vitro study of syringes containing intravitreal preparations of bevacizumab from compounding pharmacies. This study was conducted at a university-based, good manufacturing practice facility and academic ophthalmology practice. MAIN OUTCOMES AND MEASURES: Microbial culture growth, endotoxin levels, and quantity and binding affinity of protein in each sample. RESULTS: There were no microbial contaminants or endotoxin detected in any of the samples. Of the 21 compounded samples of bevacizumab obtained from 11 pharmacies, 17 (81%) had lower protein concentrations (mean [SD], 22.2 [4.9]mg/mL; range, 19.2-24.5mg/mL) compared with bevacizumab acquired directly from Genentech (25mg/mL; P 〈 .05). In 3 of 10 compounding pharmacies where more than 1 sample was available, there were statistically significant differences in the protein concentration between samples from the same compounding pharmacy. CONCLUSIONS AND RELEVANCE: Test results from intravitreal preparations of bevacizumab acquired from compounding pharmacies were negative for microbial contaminants and endotoxin. However, there were significant variations in protein concentration that appear in general to be lower than bevacizumab acquired directly from Genentech. The clinical implications of these variable protein levels remain uncertain.
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