Drug retention by inline filters--effect of positively charged polyethersulfone filter membranes on drug solutions with low concentration

Protein Adsorption of In-line Intravenous Infusion Filter and the Corresponding Mitigation Plans

Protein adsorption is one of the most frequently observed incompatibility issues during intravenous (IV) administration of therapeutic proteins, especially at low concentration, leading to a lower-than-expected drug recovery and potential insufficient therapeutic effect. With its porous structure and complex surface physicochemical property, the in-line filter is usually the main component where protein adsorption happens. Thus, comprehending the adsorption mechanism between proteins and filter membranes is essential for designing effective mitigation strategies. In this study, the adsorption behaviors for 4 proteins with different pI (isoelectric point) and hydrophobicity were evaluated after dilution to 5 μg/mL in 5% dextrose (D5W) and 0.9% sodium chloride (saline), respectively. The results showed that in-line filter is the main contributor to protein loss compared with IV bag and infusion line. The adsorption in D5W was dominated by electrostatic attraction between positively charged protein and negatively charged filter membrane. By adjusting the solution pH above the protein pI to have negatively charged protein or using positively charged filter membrane, the adsorption was effectively reduced by reducing the electrostatic attraction, while adding electrolyte solution could be similarly effective by shielding the surface charge to reduce the electrostatic attraction. In addition, adding surfactant could further reduce the adsorption induced by hydrophobic interaction between protein and contacting materials including IV bag, infusion line and in-line filter as well. When saline was used as a diluent, hydrophobic interaction between protein and filter membrane was the main cause for protein with high hydrophobicity. 0.005% (w/v) polysorbate 80 was demonstrated to be effective to elevate the dose recovery to about 100% for all the evaluated proteins. A decision tree was provided to guide the design of proper mitigation plans to reduce the protein adsorption during IV infusion based on the type of diluent, filter membrane and protein pI.

Role of Microfiltration Membrane Morphology on Nanoparticle Purification to Enhance Downstream Purification of Viral Vectors

In the rapidly advancing realms of gene therapy and biotechnology, the efficient purification of viral vectors is pivotal for ensuring the safety and efficacy of gene therapies. This study focuses on optimizing membrane selection for viral vector purification by evaluating key properties, including porosity, thickness, pore structure, and hydrophilicity. Notably, we employed adeno-associated virus (AAV)-sized nanoparticles (20 nm), 200 nm particles, and bovine serum albumin (BSA) to model viral vector harvesting. Experimental data from constant pressure normal flow filtration (NFF) at 1 and 2 bar using four commercial flat sheet membranes revealed distinct fouling behaviors. Symmetric membranes predominantly showed internal and external pore blockage, while asymmetric membranes formed a cake layer on the surface. Hydrophilicity exhibited a positive correlation with recovery, demonstrating an enhanced recovery with increased hydrophilicity. Membranes with higher porosity and interpore connectivity showcased superior throughput, reduced operating time, and increased recovery. Asymmetric polyether sulfone (PES) membranes emerged as the optimal choice, achieving ∼100% recovery of AAV-sized particles, an ∼44% reduction in model cell debris (200 nm particles), an ∼35% decrease in BSA, and the fastest operating time of all membranes tested. This systematic investigation into fouling behaviors and membrane properties not only informs optimal conditions for viral vector recovery but also lays the groundwork for advancing membrane-based strategies in bioprocessing.

A critical review of diffusive gradients in thin films technique for measuring organic pollutants: Potential limitations, application to solid phases, and combination with bioassays

Diffusive gradient in thin films (DGT) for organics has received considerable attention for studying the chemical dynamics of various organic pollutants in the environment. This review investigates current limitations of DGT for organics and identifies several research gaps for future studies. The application of a protective outer filter membrane has been recommended for most DGT applications, however, important questions regarding longer lag times due to significant interaction or adsorption of specific groups of compounds on the outer membrane remain. A modified DGT configuration has been developed that uses the diffusive gel as the outer membrane without the use of an extra filter membrane, however use of this configuration, while largely successful, remains limited. Biofouling has been a concern when using DGT for metals; however, effect on the performance of DGT for organics needs to be systemically studied. Storage stability of compounds on intact DGT samplers has been assessed in select studies and that data is synthesized here. DGT has been used to describe the kinetic desorption of antibiotics from soils and biosolids based on the soil/biosolid physical-chemical characteristics, yet applications remain limited and requires further research before wide-scale adoption is recommended. Finally, DGT for organics has been rarely, albeit successfully, combined with bioassays as well as in vivo bioaccumulation studies in zebrafish. Studies using DGT combined with bioassays to predict the adverse effects of environmental mixtures on aquatic or terrestrial biota are discussed here and should be considered for future research.

Critical Drug Loss Induced by Silicone and Polyurethane Implantable Catheters in a Simulated Infusion Setup with Three Model Drugs

Silicone and polyurethane are biocompatible materials used for the manufacture of implantable catheters, but are known to induce drug loss by sorption, causing potentially important clinical consequences. Despite this, their impact on the drugs infused through them is rarely studied, or they are studied individually and not part of a complete infusion setup. The aim of this work was to experimentally investigate the drug loss that these devices can cause, on their own and within a complete infusion setup. Paracetamol, diazepam, and insulin were chosen as models to assess drug sorption. Four commonly used silicone and polyurethane catheters were studied independently and as part of two different setups composed of a syringe, an extension set, and silicone or polyurethane implantable catheter. Simulated infusion through the catheter alone or through the complete setup were tested, at flowrates of 1 mL/h and 10 mL/h. Drug concentrations were monitored by liquid chromatography, and the silicone and polyurethane materials were characterized by ATR-IR spectroscopy and Zeta surface potential measurements. The losses observed with the complete setups followed the same trend as the losses induced individually by the most sorptive device of the setup. With the complete setups, no loss of paracetamol was observed, but diazepam and insulin maximum losses were respectively of 96.4 ± 0.9% and 54.0 ± 5.6%, when using a polyurethane catheter. Overall, catheters were shown to be the cause of some extremely high drug losses that could not be countered by optimizing the extension set in the setup.

Strategies to prevent drug incompatibility during simultaneous multi-drug infusion in intensive care units: a literature review

PURPOSE

Drug protocols in intensive care units may require the concomitant administration of many drugs as patients' venous accesses are often limited. A major challenge for clinicians is to limit the risk of simultaneously infusing incompatible drugs. Incompatibilities can lead to the formation of particles and inactivation of drugs, whose consequences on the body have already been indicated. Our objective was to assess current strategies to counter the risk of incompatible infusions and control the resulting clinical consequences.

METHODS

This review was independently conducted by three investigators in respect of the PRISMA statement. Three online databases were consulted. Full-text articles, notes, or letters written in English or French, published or in press between the 1990s and the end of February 2020, with clinical study design, were eligible. Parameters of interest were mainly number and size of particles, and a number of observed/avoided incompatibilities.

RESULTS

All in all, 382 articles were screened, 17 meeting all the acceptance criteria. The strategies outlined and assessed were filtration, the use of multi-lumen devices, the purging of infusion lines, incompatibility tables and databases, and the use of standard operating procedures.

CONCLUSION

Although many strategies have been developed in recent years to address drug incompatibility risks, clinical data is still lacking. All studies with in vitro design were excluded although some current innovative strategies, like niosomes, should be considered and studied by means of clinical data in the future.