[Qualitative differences between ranibizumab from original and ready to use syringes].

OBJECTIVE

The aim of this study was to determine the influence of time, temperature and light exposure on ranibizumab (Genentech, San Francisco, USA) in plastic syringes.

METHODS

Samples of ranibizumab were drawn from the original vials into plastic tuberculin syringes, capped and analyzed after different storage intervals under varying temperature conditions (4 °C and room temperature) and light exposure (protected and room light). The samples were tested for the pH value, protein stability and concentration as well as for the binding affinity to VEGF-165 in an ELISA (enzyme linked immunoassay). Additionally, original freshly drawn samples were compared to commercially available ready to use ranibizumab syringes analyzed up to 14 days after sampling.

RESULTS

Samples stored under the described conditions retained a stable pH. Both SDS-PAGE analysis as well as protein concentration measurements shows slightly decreasing values over time that were not additionally influenced by light exposure or room temperature. The binding affinity to VEGF-165, however, was significantly decreased (p<0.05) over time starting from the first day after sampling. A similar effect could be observed in commercially available ready to use syringes. Exposure to light and room temperature led to additional decreases in the binding affinity to VEGF-165.

CONCLUSION

Until now different socioeconomic and legal aspects have influenced the choice whether to use original vials or pre-sampled ranibizumab. A new aspect is the effect of storage in plastic syringes on the quality and biological efficacy of the antibody fragment.