Stability of alemtuzumab solutions at room temperature

The 24-hour stability of alemtuzumab solutions prepared at concentrations not included in the product label and stored in glass or polyolefin containers at room temperature was evaluated.

Triplicate solutions of alemtuzumab (6.67, 40, and 120 microg/mL) in 0.9% sodium chloride were prepared in either glass bottles or polyolefin containers and stored at room temperature under normal fluorescent lighting conditions. The solutions were analyzed by a validated stability-indicating high-performance liquid chromatography (HPLC) assay at time zero and 8, 14, and 24 hours after preparation; solution pH values were measured and the containers visually inspected at all time points. Stability was defined as the retention of ≥90% of the initial alemtuzumab concentration.

HPLC analysis indicated that the percentage of the initial alemtuzumab concentration retained was >90% for all solutions evaluated, with no significant changes over the study period. The most dilute alemtuzumab solution (6.67 microg/mL) showed some degradation (91% of the initial concentration retained at hour 24), whereas the retained concentration was >99% for all other preparations throughout the study period. Solution pH values varied by drug concentration but did not change significantly over 24 hours. No evidence of particle formation was detected in any solution by visual inspection at any time during the study.

Solutions of alemtuzumab 6.67 microg/mL stored in glass bottles and solutions of 40 and 120 microg/mL stored in polyolefin containers were stable for at least 24 hours at room temperature.