Microparticles and Nanoparticles Delivered in Intravenous Saline and in an Intravenous Solution of a Therapeutic Antibody Product

Abstract

Intravenous (IV) infusion is used for administration of a large proportion of biologic therapeutics, including most monoclonal antibody products. In this study, we determined the subvisible particle levels in IV solutions and after the solutions were processed with an IV administration setup that mimicked the typical clinical method of administration. IV saline in bags manufactured by both Hospira and Baxter contained 1600-8000 microparticles/mL and 4-73 × 10⁶ nanoparticles/mL in solution. When IV immunoglobulin was diluted into the IV saline, 3700-23,000 microparticles/mL and 18-240 × 10⁶ nanoparticles/mL were detected. During processing of the solution through the IV system, in-line filters removed most microparticles. However, there were still 1-21 × 10⁶ nanoparticles/mL in IV saline and 7-83 × 10⁶ nanoparticles/mL in IV immunoglobulin diluted in saline. Finally, in samples processed through in-line filters, we found relatively large microparticles (20-60 μm) that were composed of protein or polycarbonate. These particles resulted from shedding of polycarbonate and sloughing off of protein films downstream from the filter membrane. Overall, the results document that even with in-line filters in place, high levels of subvisible particles are delivered to patients and there is a need for improved, more effective filters and IV solutions with lower particle levels.

Keywords: IgG antibody; adsorption; microparticles; nanoparticles; particle size; protein aggregation; protein delivery.

Figure 1

Setup in the lab replicating a typical IV infusion system used at the Outpatient Infusion Center at the University of Colorado Hospital

Figure 2

Particle concentrations in saline from an IV bag, and after the saline solution was processed through the infusion set, with or without an in-line filter connected to the IV tube. (Left panel) - Particles ≥ 1 μm from MFI analysis for three individual 250 mL IV saline bags manufactured by Hospira and (right panel) - particle distribution between 60–500 nm for one representative IV bag from NTA analysis. Results are shown for: initial sample collected from the injection port of the IV bag (a and b); sample processed through the infusion set connected without a filter (c and d); sample processed with a 1.2 μm Baxter in-line filter (e and f); and sample processed with a 0.2 μm Baxter in-line filter (g and h). Error bars indicate SD for 5 independent measurements of particles in the same sample.

Figure 3

Particle concentrations in IV saline bags and after the saline solution was processed through the infusion set, with or without an in-line filter connected to the IV tube. Three IV bags manufactured by Hospira and Baxter in 250 mL and 100 mL volume each were tested. Total particle concentrations are shown for: ≥ 1 μm from MFI analysis (a); ≥ 2 μm from FC analysis (b); and ≥ 60 nm from NTA analysis (c). Three different in-line filters were tested with the IV tubes; 1.2 μm pore size manufactured by CareFusion (CF); 1.2 μm pore size manufactured by Baxter (BX); and a 0.2 μm pore size manufactured by Baxter. Each datum point shows mean of particle counts obtained for a sample processed from one IV bag. Error bars indicate SD for 5 independent measurements of particles in the same sample.

Figure 4

Particle concentrations in IVIG diluted in IV saline bag, and after it was processed through the infusion set, with or without an in-line filter connected to the IV tube. (Left panel) -particles ≥ 1 μm from MFI analysis for IVIG samples from three individual 250 mL IV saline bags manufactured by Hospira and (right panel) - particle distribution between 60–500 nm for one representative IV bag from NTA analysis. Results are shown for: initial sample collected from the injection port of the IV bag (a and b); sample processed through the infusion set connected without a filter (c and d); sample processed with a 1.2 μm Baxter in-line filter (e and f); and sample processed with a 0.2 μm Baxter in-line filter (g and h). Error bars indicate SD for 5 independent measurements of particles in the same sample.

Figure 5

Particle concentrations in IVIG diluted in IV saline bag and after it was processed through the infusion set, with or without an in-line filter connected to the IV tube. IVIG diluted into three IV bags manufactured by Hospira and Baxter in 250 mL and 100 mL volume each were tested. Total particle concentrations are shown for: ≥ 1 μm from MFI analysis (a); ≥ 2 μm from FC analysis (b); and ≥ 60 nm from NTA analysis (c). Three different in-line filters were tested with the IV tubes; 1.2 μm pore size manufactured by CareFusion (CF); 1.2 μm pore size manufactured by Baxter (BX); and a 0.2 μm pore size manufactured by Baxter (BX). Each datum point shows mean of particle counts obtained for a sample processed from one IV bag. Error bars indicate SD for 5 independent measurements of particles in the same sample.

Figure 6

Particle concentrations as a function of volume of IVIG-saline solution processed through the IV tube with an in-line filter connected to the IV tube. Total particle concentrations ≥ 1 μm (a); ≥ 10 μm (b); and ≥ 15 μm (c) from MFI analysis. Three different in-line filters were tested: a 0.2 μm pore size manufactured by Baxter (BX); a 1.2 μm pore size manufactured by Baxter (BX); and a 1.2 μm pore size manufactured by CareFusion (CF). Error bars indicate SD for 3 independent measurements of particles in the same sample.

Figure 7

Particle images captured during FlowCAM analysis of IVIG-saline solution processed through the IV tubes with in-line filters from Baxter (BX) or Care Fusion (CF).

Figure 8

Representative images and Raman spectrum obtained by Morphologi G3-ID upon analysis of IVIG processed through the IV tube connected to a 0.2μm Baxter in-line filter. Image of a protein particle (a); Raman spectrum for the protein particle (b); image for polycarbonate particle (c); and Raman spectrum for polycarbonate (d). Black spectrum is for the sample particle and orange is the reference spectrum from the Raman spectral library.

Figure 9

Representative images of: fluorescently labeled IVIG adsorbing to the surface of an IV tube (a); particle images from saline used to flush the IV tube (b); filter membrane (c); and tube downstream from the filter membrane (d). An IVIG-saline solution spiked with fluorescently labeled IVIG molecules was processed through the IV system with a 0.2μm Baxter in-line filter.