Accelerated stability study of a reference standard for determining the potency of human anti-D immunoglobulin

INTRODUCTION. Stability of the reference standard for human anti-D immunoglobulin is a key prerequisite for the accuracy of its potency determination. Accelerated stability testing allows comparing several formulations of the protective medium in a short time and selecting the most effective one for long-term stability of the reference standard. AIM. To select a stabilizer for the reference standard used for determining the potency of human anti-D immunoglobulin by means of accelerated stability testing. MATERIALS AND METHODS. The study objects were candidates for the reference standard (CRS), which consisted of freeze-dried anti-D antibodies in three formulations (F1, F2, F3): F1 (glycine 18.8 g/L and sodium chloride 4.0 g/L), F2 (glycine 12.5 g/L and L-proline 12.5 g/L), and F3 (trehalose 40.0 g/L and bovine serum albumin 2.0 g/L). Anti-D antibody content was determined by flow cytometry; molecular size distribution was assessed by high-performance liquid chromatography; and clarity and color were measured spectrophotometrically. The CRS with different protective medium compositions were compared by kinetic modeling using the Arrhenius equation. RESULTS. During lyophilization, the potency (anti-D antibody content), protein content, molecular size distribution, clarity, and color of the CRS were preserved, indicating that the studied protective media are effective lyoprotectants. Under accelerated stability testing conditions, a decrease in anti-D antibody content was observed after 168 days of storage. Using the Arrhenius model, the estimated shelf lives at a storage temperature of 5±3 °C for the CRS were 20, 13, and 8 years for formulations F3, F2, and F1, respectively. Moreover, the CRS stabilized with trehalose and bovine serum albumin showed less change in molecular size distribution, clarity, color, and solubility. This makes it possible to predict the stability of anti-D antibodies against chemical degradation and protein aggregation during long-term storage when this formulation is used. CONCLUSIONS. Trehalose (40.0 g/L) with the addition of bovine serum albumin (2.0 g/L) was selected as the stabilizer for the human anti-D immunoglobulin reference standard, ensuring the stability of anti-D antibodies during lyophilization and storage.