Physical Compatibility of Y-site Pediatric Drug Administration: A Call for Question of US Pharmacopeia Standards.

OBJECTIVE: To evaluate the physical intravenous Y-site compatibility of 29 combinations of medications at commonly used pediatric concentrations using both existing and novel techniques. METHODS: Medication combinations included were selected by a varied group of pediatric inpatient pharmacists, and then assessed by 3 independent reviewers for existing literature. For each combination, 2 different medications were mixed together in a 1:1 ratio and incubated at room temperature for 4 hours to simulate Y-site administration. Each sample was then analyzed using the US Pharmacopeia (USP) <788> recommended analytical technique of light obscuration (LO) in addition to novel flow imaging (FI) microscopy and backgrounded membrane imaging (BMI). Physical compatibility was determined using USP chapter <788> large volume particle count limits for all techniques. RESULTS: A total of 29 different medication combinations were studied. Five combinations met criteria for compatibility by all 3 techniques. The remaining 24 combinations reached the threshold to be considered incompatible by at least 1 of the 3 techniques. Light obscuration, BMI, and FI identified 14%, 59%, and 76% of combinations as incompatible, respectively. All samples deemed incompatible by LO were also incompatible by at least 1 of the other 2 techniques. Flow imaging and BMI results agreed in 69% of samples tested. CONCLUSIONS: Most combinations tested were found to be incompatible by at least 1 of the 3 instruments used. Light obscuration appears to have reduced accuracy for identifying particulate resulting in physical medication incompatibility when compared with the novel techniques of FI and BMI.

Physical compatibility of medications with concentrated neonatal and pediatric parenteral nutrition: A simulated Y-site drug compatibility study.

BACKGROUND: The physical intravenous Y-site compatibility of 15 different medications with highly concentrated neonatal and pediatric parenteral nutrition (PN) compounds is described, using existing and novel methods. METHODS: PN formulations were developed based on common prescribing practices in a 400+-bed freestanding children's hospital. Medications at commonly used pediatric concentrations were mixed in a 1:1 ratio with both pediatric and neonatal PN formulations and incubated at room temperature for 4 h to simulate Y-site administration. Samples were then analyzed using the light obscuration (LO) technique, as recommended by United States Pharmacopeia (USP) chapter 788, in addition to novel flow imaging (FI) microscopy and backgrounded membrane imaging (BMI). Physical compatibility was determined using USP 788 particle count limits for all techniques. RESULTS: Most combinations were found to be compatible per USP 788 thresholds. Pediatric PN was incompatible by at least two methods with cisatracurium 2 mg/ml, sildenafil 0.8 mg/ml, furosemide 10 mg/ml, and ketamine 10 mg/ml. Neonatal PN was incompatible by at least two methods with cisatracurium 2 mg/ml and furosemide 10 mg/ml. Overall, results for 20 of the 30 combinations (66%) agreed across all three methods. FI and BMI results agreed for 22 of 30 combinations. LO agreed with FI in 25 of 30 combinations, and BMI and LO results agreed in 23 of 30 combinations. CONCLUSION: Most combinations tested were found to be compatible across all methods. Novel methods of FI and BMI seem useful to further evaluate LO findings and improve accuracy of particle counts when assessing PN-medication combinations.

Quantitative assessment of silicone oil release with siliconized and silicone oil-free syringes by microflow imaging microscopy / Avaliação quantitativa da liberação de óleo de silicone por seringas siliconizadas e sem óleo de silicone usando microflow imaging microscopy

ABSTRACT Purpose: Since particles are released in syringes during intravitreal injections, we assessed them quantitatively after agitating syringes commonly used for intravitreal injections. Methods: With and without agitation, the SR 1-ml insulin, Becton-Dickinson Ultra-Fine 0.3-ml Short Needle with a half-unit scale, HSW Norm-Ject Tuberculin, and Becton-Di­ckinson 1-ml Luer Lok Tip were examined with buffer and bevacizumab, aflibercept, and ziv-aflibercept. Flow imaging microscopy was performed to assess the particle numbers, concentrations, morphology, and size distribution. Results: Using the Becton-Dickinson Ultra-Fine syringe, the average particle count after agitation was higher than in the no-agitation group. For particles greater than 10 and 25 µm, differences were observed using the SR syringe between the two studied conditions. There were no significant differences in the means for the other syringes. Without agitation, the SR syringe had the highest number of particles (2,417,361.7 ± 3,421,575.5) followed by the Becton-Dickinson Ultra-Fine with 812.530,9 ± 996.187,2. The Becton-Dickinson Luer Lok Tip and HSW Norm-Ject performed equally with 398,396.8 ± 484,239.2 and 416,016.4 ± 242,650.1 particles, respectively. Conclusions: Flicking syringes to eliminate air bubbles results in increased numbers of particles released during intravitreal injections into the human vitreous.

RESUMO Objetivo: Visto que partículas são liberadas nas seringas durante as injeções intravítreas (IVIs), estas foram avaliadas quantitativamente após a agitação das seringas mais comumente usadas para injeções intravítreas. Métodos: A seringa SR de 1 ml de insulina, a agulha curta Becton-Dickinson Ultra-Fine 0,3 ml com escala de meia unidade, HSW Norm-Ject Tuberculin e a Becton-Dickinson Luer Lok Tip de 1 ml foram estudadas com placedo e com bevacizumabe, aflibercept e ziv-aflibercept, com e sem agitação. MicroFlow Imaging Mi­croscopy foi realizada para avaliar o número de partículas, con­centração, morfologia e distribuição das mesmas por tamanho. Resultados: A contagem média de partículas após agitação foi maior do que no grupo sem agitação usando a seringa Becton-Di­ckinson Ultra-Fine. Diferenças foram observadas usando a seringa SR entre as duas condições estudadas para partículas maiores que 10 e 25 µm. Para as demais seringas, não foram observadas diferenças significativas nas médias. A seringa SR apresentou o maior número de partículas sem agitação (2.417.361,7 ± 3.421.575,5) seguida da Becton-Dickinson Ultra-Fine com 812.530,9 ± 996.187,2. A BD Luer Lok Tip e a HSW Norm-Ject se comportaram de forma semelhante com 398.396,8 ± 484.239,2 e 416.016,4 ± 242.650,1 partículas, respectivamente. Conclusões: Agitar seringas para remover bolhas de ar resulta em um maior número de partículas liberadas durante Becton-Dickinson no vítreo humano.

Exploring the Protein Stabilizing Capability of Surfactants Against Agitation Stress and the Underlying Mechanisms.

The application of surfactants in liquid protein formulation is a common practice to protect proteins from liquid-air interface-induced protein aggregation. Typically, Polysorbate 20 or 80 are used, but degradation of these surfactants can result in particle formation and/or protein degradation. The purpose of the current study was to directly compare three alternative protein stabilizing molecules - Poloxamer 188, hydroxypropyl-cyclodextrin and a trehalose-based surfactant - to Polysorbate 80 for their capacities to reduce agitation-induced protein aggregation and particle formation; and furthermore, investigate their underlying protein stabilizing mechanisms. To this end, a small-volume, rapid agitation stress approach was used to quantify the molecules' abilities to stabilize two model proteins. This assay was presented to be a powerful tool to screen the protein stabilizing capability of surfactants using minimum of material and time. SEC, turbidity measurements and particle analysis showed an efficient protein stabilization of all tested surfactants as well as cyclodextrin. STD-NMR and dynamic surface tension measurements indicated the competitive surface adsorption to be the main protein stabilizing mechanism of the three surfactants tested. It might also play a role to some extent in the protein stabilization by HPßCD. However, additional mechanisms might also contribute to protein stabilization leaving room for further investigations.

Quantitative assessment of silicone oil release with siliconized and silicone oil-free syringes by microflow imaging microscopy.

PURPOSE: Since particles are released in syringes during intravitreal injections, we assessed them quantitatively after agitating syringes commonly used for intravitreal injections. METHODS: With and without agitation, the SR 1-ml insulin, Becton-Dickinson Ultra-Fine 0.3-ml Short Needle with a half-unit scale, HSW Norm-Ject Tuberculin, and Becton-Di-ckinson 1-ml Luer Lok Tip were examined with buffer and bevacizumab, aflibercept, and ziv-aflibercept. Flow imaging microscopy was performed to assess the particle numbers, concentrations, morphology, and size distribution. RESULTS: Using the Becton-Dickinson Ultra-Fine syringe, the average particle count after agitation was higher than in the no-agitation group. For particles greater than 10 and 25 µm, differences were observed using the SR syringe between the two studied conditions. There were no significant differences in the means for the other syringes. Without agitation, the SR syringe had the highest number of particles (2,417,361.7 ± 3,421,575.5) followed by the Becton-Dickinson Ultra-Fine with 812.530,9 ± 996.187,2. The Becton-Dickinson Luer Lok Tip and HSW Norm-Ject performed equally with 398,396.8 ± 484,239.2 and 416,016.4 ± 242,650.1 particles, respectively. CONCLUSIONS: Flicking syringes to eliminate air bubbles results in increased numbers of particles released during intravitreal injections into the human vitreous.

Effects of Transportation of IV Bags Containing Protein Formulations Via Hospital Pneumatic Tube System: Particle Characterization by Multiple Methods.

In hospitals, often drug products in intravenous (IV) bags are transported via pneumatic tube systems (PTS). The goal of this study was to evaluate the effects of such transportation of protein products on particle formation in polyvinyl chloride (PVC) and polyolefin (PO) IV bags, containing either IV saline or dextrose. We studied intravenous immunoglobulin (IVIG) and a monoclonal antibody (mAb). Particles were quantified with flow imaging, light obscuration and nanoparticle tracking analysis. PTS transportation of IVIG caused large increases in protein particle concentrations, with much greater increases observed in saline than in dextrose. The increases were greater in IV solutions in PO than those in PVC bags. With the mAb, PTS transportation in saline caused increases in protein particle levels in PO bags, but not in PVC bags. Transportation in dextrose did not result in significant increases in mAb particle concentrations in IV bags made of either material. Overall, the results document that the PTS transportation can result in large increases in protein particles and that magnitude of these increases depends the protein itself, the bag material and the IV solution. The main conclusion is that protein products in IV solutions should not be transported in hospital PTS.

Chemical-gas Sterilization of External Surface of Polymer-based Prefilled Syringes and Its Effect on Stability of Model Therapeutic Protein.

To reduce the risk of infection during intravitreal injections, the external surface of prefilled syringes (PFSs) must be sterilized. Usually, ethylene oxide (EO) gas or vaporized hydrogen peroxide (VHP) is used for sterilization. More recently, nitrogen dioxide (NO2) gas sterilization has been developed. It is known that gas permeability is approximately zero into glass-PFSs. However, polymer-PFSs (P-PFSs) have relatively high gas permeability. Therefore, there are concerns about the potential impact of external surface sterilization on drug solutions in P-PFSs. In this study, P-PFSs [filled with water for injection (WFI) or human serum albumin (HSA) solution] were externally sterilized using EO, VHP, and NO2 gases. For the WFI-filled syringes, the concentration of each gas that ingressed into the WFI was measured. For the HSA solution-filled syringes, the physical and chemical degradation of HSA molecules by each sterilant gas was quantified. For the EO- or VHP-sterilized syringes, the ingressed EO or hydrogen peroxide (H2O2) molecules were detected in the filled WFI. Additionally, EO-adducted or oxidized HSA molecules were observed in the HSA-filled syringes. In contrast, the NO2-sterilized WFI-filled syringes exhibited essentially immeasurable ingressed NO2, and protein degradation was not detected in HSA-filled syringes.

Mimicking Low pH Virus Inactivation Used in Antibody Manufacturing Processes: Effect of Processing Conditions and Biophysical Properties on Antibody Aggregation and Particle Formation.

Low pH virus inactivation (VI) step is routinely used in antibody production manufacturing. In this work, a mimic of the VI step was developed to focus on evaluating adverse effects on product quality. A commercially available lab-scale glass reactor system was utilized to assess impacts of process and solution conditions on process-induced monoclonal antibody particle formation. Flow imaging was found to be more sensitive than light obscuration in detecting microparticles. NaOH as a base titrant increased protein microparticles more than Tris. Both stirring and NaCl accelerated particle formation, indicating that interfacial stress and protein colloidal stability were important factors. Polysorbate 80 was effective at suppressing particle formation induced by stirring. In contrast, trehalose led to higher microparticle levels suggesting a conformational stabilizer may have other adverse effects during titration with stirring. Additionally, conformational and colloidal stability of antibodies were characterized to investigate the potential roles of antibody physicochemical properties in microparticle formation during VI. The stability data were supportive in rationalizing particle formation behaviors, but they were not predictive of particle formation during the mimicked viral inactivation steps. Overall, the results demonstrate the value of testing various solution and processing conditions in a scaled-down system prior to larger-scale VI bioprocesses.

In-vitro assessment of release of silicone oil droplets with the use of variety of syringes and needles used in intravitreal injections.

PURPOSE: To assess the variability of silicone oil (SO) particles released across syringes from the same lot and the role of different needle gauges. MATERIALS AND METHODS: Four syringe models and six needle models were assessed for SO release. About 50 microliters of a buffer solution were loaded into the syringe, needle or syringe/needle setup. The data were analyzed by imaging flow cytometry with fluorescently labeling for SO. RESULTS: All syringe models had a high coefficient of variation in SO release across syringes from the same lot. The amount of SO was significantly greater in the syringe when the needle was attached. SO particles with the BD 30G needle attached to the syringe were statistically greater than the 27G counterpart (p = 0.005). None of the other comparisons was statistically different. Finally, the number of SO particles was higher in the syringe/needle setup than in needles only (p = 0.0024). CONCLUSION: We found a high variability in SO content across syringes from the same lot. Additionally, there was no clear association between needle gauge and the number of SO particles, as well as their coefficient of variation. Finally, the needles accounted for a small number of SO particles in comparison to the combined syringe-needle setup.

Silicone oil-free syringes, siliconized syringes and needles: quantitative assessment of silicone oil release with drugs used for intravitreal injection.

PURPOSE: This study aimed to quantify the amount of silicone oil (SO) released across a variety of syringe and needle models routinely used for intravitreal injection. METHODS: The release of SO was assessed in eight models of syringes, two of which were reported to be 'SO-free', and eleven models of needles with unknown SO content. To evaluate SO release within the context of anti-VEGF therapeutics, syringes were evaluated using aflibercept, bevacizumab, buffer, ziv-aflibercept and formulation buffer. All syringe tests were performed with or without agitation by flicking for syringes. Needles were evaluated without agitation only. Samples were fluorescently labelled to identify SO, and triplicate measurements were collected using imaging flow cytometry. RESULTS: Seven out of 8 syringe models showed a statistically significant increase in the SO particle count after agitation. The two SO-free syringe models (HSW Norm-Ject, Daikyo Crystal Zenith) released the least SO particles, with or without agitation, whereas the BD Ultra-Fine and Saldanha-Rodrigues syringes released the most. More SO was released when the syringes were prefilled with formulation buffer than with ziv-aflibercept. Syringes filled with aflibercept and bevacizumab had intermediate levels. Agitation increased the release of SO into each of the drug solutions. Silicone oil (SO) was detected in all needles. CONCLUSIONS: Agitation of the syringe by flicking leads to a substantial increase in the number of SO particles. Silicone oil (SO)-free syringes had the best performance, but physicians must also be aware that needles are siliconized and also contribute to the injection of SO into the vitreous.

Subvisible Particles in Solutions of Remicade in Intravenous Saline Activate Immune System Pathways in In Vitro Human Cell Systems.

Among patients that receive Remicade® therapy, more than 20% have adverse infusion related reactions and approximately 50% have immunogenic responses.1-3 Upon characterization of initial Remicade®-IV solution we observed a high concentration of subvisible particles that could inadvertently be delivered to patients. This solution was processed through the IV infusion system, mimicking the typical clinical administration setup - either with or without an in-line filter connected to the IV line. The samples generated thereafter were tested using various in vitro assays for activation of the innate immune system via cytokine release in whole blood and in peripheral blood mononuclear cell (PBMC) cultures, and activation of the Toll like receptors (TLRs). Activation of the adaptive immune system was evaluated by monitoring upregulation of surface receptors on dendritic cells (DCs) and CD4+ T cell proliferation in response to IV solution of Remicade®. Our results indicate that subvisible particles in Remicade®-saline solution have a significant role in activation of the immune system but there are extrinsic factors potentially contributed by the in-line filters or other process parameters that also contribute to immune system activation.

High particle variability across siliconized and oil-free syringes and needles from the same lots.

Previous studies have reported silicone oil (SO) applied to needles and syringes in the vitreous of patients after intravitreal injections. We evaluated four syringes (SR 1-mL insulin, Saldanha-Rodrigues; BD 1-mL Tuberculin Slip Tip, Becton-Dickinson; BD Ultra-Fine 0.3 mL, HSW Norm-Ject Tuberculin, Henke Sass Wolf) and 10 needles (BD PrecisionGlide 27- and 30-gauge (G); BD Eclipse and JBP Nanoneedle 27-, 30-, 33- and 34-G; TSK Invisible Needle and 27 and 30-G Steriject Control Hub). The protein-free buffer samples injected into the syringes and needles under study were collected in an Eppendorf tube and taken to Flow imaging microscopy, that characterized the concentration and morphology of the microsized particles. The number of particles was analyzed. The coefficients of variation (CV) were the primary outcome. The Feltz and Miller test compared the CVs. The significance level was 5%. Numerous particles and high CVs were associated with both devices, needles and syringes; the comparisons among them did not reach significance. The BD Ultrafine 0.3 mL syringe (149.7%) had the highest CV and the SO-free HSW Norm-Ject (66.4%) syringe the lowest, and the TSK Invisible needle (149.5%) had the highest and the BD Precision Glide 30G needle (35.9%) needle the lowest. In conclusion, particle release, including those with SO morphology, varied greatly among instruments, even from the same lots, which is relevant considering that fewer particles are injected into some eyes compared with others.

Compatibility of medications with intravenous lipid emulsions: Effects of simulated Y-site mixing.

PURPOSE: To determine the physical intravenous Y-site compatibility of 19 commonly used medications at pediatric concentrations with 3 different types of lipid emulsion. METHODS: Medications at commonly used pediatric concentrations were mixed in a 1:1 ratio with lipid emulsions (Intralipid, Nutrilipid, and Smoflipid) and incubated at room temperature for 4 hours to simulate Y-site administration. Each sample was then diluted with particle-free water and analyzed using the analytical technique of light obscuration recommended in United States Pharmacopeia (USP) general information chapter 729 (USP <729>). Physical compatibility was determined by measuring the percentage of fat residing in globules larger than 5 µm (PFAT5) per USP <729> recommendations. RESULTS: Most combinations tested were physically compatible based on USP <729> regulations. Incompatibilities differed for the different brands of lipid emulsion. The two combinations that met USP <729> criteria for physical incompatibility were cisatracurium 2 mg/mL with Intralipid and gentamicin 2 mg/mL with Smoflipid. CONCLUSION: Three different lipid emulsions were physically compatible at the Y site with the majority of medications tested. Data regarding Y-site compatibility for one lipid emulsion product cannot be safely extrapolated to another without additional testing.

The Impact of Formulation Composition and Process Settings of Traditional Batch Versus Continuous Freeze-Drying On Protein Aggregation.

The long-term stability of therapeutic protein products can be extended by freeze-drying. However, the freeze-drying process itself has several harmful stresses. A rationalized formulation design can significantly mitigate protein damage caused by freezing, dehydration and interfacial stresses of lyophilization and reconstitution. Recently, a continuous spin-freeze-drying concept was proposed as a more economical, controllable, flexible and qualitative alternative to batch freeze-drying. The purpose of this work is to compare spin-freeze-drying to traditional batch freeze-drying with regard to protein physical stability. The impacts of spinning, freezing and drying were investigated for both processing methods. Herewith, the interaction between these process phases and two common rational formulation strategies, (i.e. adding a disaccharide and a surfactant) was examined. Protein aggregates formed due to the process phase stresses were characterized with particle counting techniques and size exclusion chromatography. It was found that spin-freeze-drying exhibited essentially identical stresses causing comparable aggregation in all the process phases as compared to batch freeze-drying. Moreover, there were also analogous impacts of the formulation excipients. These observations led to the conclusion that similar freeze-drying formulation excipients and strategies tested for decades in batch freeze-drying of proteins can be utilized for spin-freeze-drying; in order to maintain protein stability during processing.

Substandard Quality of the Antimicrobials Sold in the Street Markets in Haiti.

This pilot study was conducted to analyze the quality of the antimicrobials sold in the street markets in Port-au-Prince, Haiti. A total of 258 packs containing antimicrobials were bought in 28 street markets in Port-au-Prince (Haiti). Tablets and contents of capsules included in 196 packs were analyzed using a Raman handheld spectrometer (NanoRAM of BWTEK, Model: BWS456-785) during the first quarter of 2019. Three out of 11 antimicrobials (Amoxicillin, Metronidazole, and Cotrimoxazole) had a high spectral match with an HQI ≥ 90 to the respective authentic medicine for more than 95% of their tablets/capsules. For six antimicrobials (Tetracycline, Erythromycin, Cloxacillin, Azithromycin, Clarithromycin, and the combination Amoxicillin + Clavulanic Acid) none of their tablets/capsules showed a sufficient spectral match with the authentic medicine. This finding indicates that these products sold in the markets did not contain the labeled drug and/or contained a degraded drug. In addition to the fact that prescription antimicrobials can be purchased in street markets, the present field study found that for most of them (including "Watch" antimicrobials according to the AWaRe classification) were substandard, which contributes to the present antimicrobials resistance epidemic.

Effects of Tubing Type, Operating Parameters, and Surfactants on Particle Formation During Peristaltic Filling Pump Processing of a mAb Formulation.

Filling pump operation is an important cause of particle formation in therapeutic protein formulations. The goals of the present study were to investigate the impacts of peristaltic filling pump tubing type, pump operating parameters (acceleration and velocity), and formulation on both nanoparticle and microparticle formation in water, placebo, and a 120 mg/mL mAb drug formulation. Microparticles were quantified using flow imaging microscopy and light obscuration, and nanoparticles were counted with nanoparticle tracking analysis. Pumping of all solutions through Pharmed® tubing resulted in much higher particle levels than processing with Accusil™ or Masterflex® tubing. Pump acceleration did not measurably affect particle levels in pumped solutions, but in some cases, a relatively high pumping velocity of 400 rpm enhanced nanoparticle formation. The presence of surfactants reduced pumping-induced particle formation in the mAb solution, and the effects of 4 different surfactants tested were similar. Biophysical properties (secondary and tertiary structure, and thermal stability) of the protein in solution were not altered by pumping. Overall, this study demonstrates that investigations of pumping parameters and formulations using both nanoparticle and microparticle measurement methods are important for understanding pumping-induced particle formation and developing effective control strategies.

Effects of Tubing Type, Formulation, and Postpumping Agitation on Nanoparticle and Microparticle Formation in Intravenous Immunoglobulin Solutions Processed With a Peristaltic Filling Pump.

The main goal of this study was to use state-of-the-art instruments for nanoparticle (nanoparticle tracking analysis and resonant mass measurement) and microparticle counting (flow imaging) to assess the effects of peristaltic filling pump operation on particle formation in formulations of intravenous immunoglobulin. Microparticle levels were also measured with light obscuration. Postpumping agitation was studied as an accelerated degradation method, 3 different commercial peristaltic tubing types were tested, and the effects of formulation pH and inclusion of polysorbate 80 were determined. Overall, the results documented that nanoparticle measurements, as well as microparticle determinations with flow imaging, were essential to gain rigorous insights into impacts of processing and formulation parameters on pumping- and agitation-induced particle formation. In addition, light obscuration was a relatively insensitive method and failed to detect large increases in protein particles caused by pumping and postpumping agitation. Formulation studies showed that the presence of polysorbate 80 or increasing protein colloidal stability with appropriate choice of buffer generally reduced particle formation. The results highlight the need for filling pump assessments in formulation development studies. Combining such assessments with appropriate analytical methods should help assure that particle levels are controlled during filling pump operation and that the highest quality products are manufactured.

DEHP Nanodroplets Leached From Polyvinyl Chloride IV Bags Promote Aggregation of IVIG and Activate Complement in Human Serum.

Concerns regarding the impact of subvisible particulate impurities on the safety and efficacy of therapeutic protein products have led manufacturers to implement strategies to minimize protein aggregation and particle formation during manufacturing, storage, and shipping. However, once these products are released, manufacturers have limited control over product handling. In this work, we investigated the effect of di(2-ethylhexyl) phthalate (DEHP) nanodroplets generated in polyvinyl chloride (PVC) bags of intravenous (IV) saline on the stability and immunogenicity of IV immunoglobulin (IVIG) formulations. We showed that PVC IV bags containing saline can release DEHP droplets into the solution when agitated or transported using a pneumatic tube transportation system in a clinical setting. We next investigated the effects of emulsified DEHP nanodroplets on IVIG stability and immunogenicity. IVIG adsorbed strongly to DEHP nanodroplets, forming a monolayer. In addition, DEHP nanodroplets accelerated IVIG aggregation in agitated samples. The immunogenicity of DEHP nanodroplets and IVIG aggregates generated in these formulations were evaluated using an in vitro assay of complement activation in human serum. The results suggested DEHP nanodroplets shed from PVC IV bags could reduce protein stability and induce activation of the complement system, potentially contributing to adverse immune responses during the administration of therapeutic proteins.