Evaluation of subvisible particles in human immunoglobulin and lipid nanoparticles repackaged from a multi-dose vial using plastic syringes.

The multi-dose vial (MDV) is widely used for most biopharmaceuticals that are repackaged in plastic syringes before use. However, subvisible particle formation with the use of plastic syringes containing silicone oil (SO syringes) for handling therapeutic proteins can be problematic. This study aimed to evaluate the extent of and trends in microparticle (>1 µm) formation and accumulation in repackaged syringes from MDVs containing human immunoglobulin (IgG) and lipid nanoparticles (LNPs). Light obscuration (LO) and flow imaging (FI) were used to analyze the microparticles. The number of microparticles observed with the use SO syringes was greater than that with SO-free syringes, and the number of microparticles continuously increased as did the number of times of repackaging in syringes for both drugs. However, a large variation was observed across different brands of SO syringes. In contrast, using a different technique of drug withdrawal from the vial significantly reduced the number of microparticles. Furthermore, the use of filter-integrated needles or the inclusion of stabilizers such as acetyl-arginine and Tween 20 into the formulation also helped reduce particle formation.

Enhanced protein aggregation suppressor activity of N-acetyl-l-arginine for agitation-induced aggregation with silicone oil and its impact on innate immune responses.

Previously, N-acetyl-l-arginine (NALA) suppressed the aggregation of intravenous immunoglobulins (IVIG) more effectively and with a minimum decrease in transition temperature (Tm) than arginine monohydrochloride. In this study, we performed a comparative study with etanercept (commercial product: Enbrel®), where 25 mM arginine monohydrochloride (arginine) was added to the prefilled syringe. The biophysical properties were investigated using differential scanning calorimetry (DSC), dynamic light scattering (DLS), size-exclusion chromatography (SEC), and flow-imaging microscopy (FI). NALA retained the transition temperature of etanercept better than arginine, where arginine significantly reduced the Tm by increasing its concentration. End-over-end rotation was applied to each formulation for 5 days to accelerate protein aggregation and subvisible particle formation. Higher monomeric content was retained with NALA with a decrease in particle level. Higher aggregation onset temperature (Tagg) was detected for etanercept with NALA than arginine. The results of this comparative study were consistent with previous study, suggesting that NALA could be a better excipient for liquid protein formulations. Agitated IVIG and etanercept were injected into C57BL/6J female mice to observe immunogenic response after 24 h. In the presence of silicone oil, NALA dramatically reduced IL-1 expression, implying that decreased aggregation was related to reduced immunogenicity of both etanercept and IVIG.