Impact of the nature and concentration of plasticizers on the ability of PVC to sorb drug

Comparative Study of Sorption Phenomena Between Three Medications and Syringes Made of Cyclic Olefin Copolymer or Polypropylene

INTRODUCTION

Medical syringes are widely used in hospitals to store and administer drugs, and the contact time between the drugs and these syringes can vary from a few minutes to several weeks like for pharmaceutical preparations. The aim of this comparative study was to evaluate the potential sorption phenomena occurring between three drugs (paracetamol, diazepam and insulin aspart) and polypropylene syringes (PP) or syringes made of Cyclic Olefin Copolymer (COC).

MATERIALS AND METHODS

50 mL 3-part syringes made of either COC with crosslinked silicone on the barrel inner surface (COC-CLS) and a bromobutyl plunger seal, or PP lubricated with silicone oil (PP-SOL) with a polyisoprene plunger seal were used.

RESULTS

COC-CLS syringes induced less sorption of diazepam and insulin than PP-SOL syringes and the plunger seal material seemed to be the main cause of these interactions. An alkalinization of the medications in contact with the PP-SOL syringes was observed. It could be caused by leachable compounds and should be investigated further.

CONCLUSION

This work shows once again that it is essential to consider content-container interactions to help improve the safe use of parenteral drugs.

Insulin Adsorption onto PE and PVC Tubings

We investigate the adsorption of insulin onto PE and PVC materials by using HPLC measurements and computer simulations. We interpret the experiments by calculating the Gibbs free energy profiles during the adsorption process. The values of free energy of adsorption show a good agreement with the experimental measurements. The adsorption of insulin onto the different materials is characterized through the conformational changes with respect to its conformation in water and the interfacial regions, which are described by specific arrangements of polymer chains, water, insulin, and plasticizer molecules.

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.

[Infusion sets in neonatology: What practices in France?]

OBJECTIVES

Therapeutic management of ill newborns can require complex infusion practices using medical devices (MD). Currently, there does not exist any recommendations concerning these infusion practices. The objective of this work was to study and characterise French infusion methods neonatal and neonatal intensive care units.

MATERIALS AND METHODS

The study was performed in 2019, during 6 months. French hospitals possessing high (type 3) or medium (type 2B) grade maternity ward were contacted and asked to complete a 5 part online survey, to gather general information about the hospital/ward, infusion methods (overall and detailed), and detailed information about the medications and MD used.

RESULTS

The participation level was of 19.6 % Type 3 maternities use overall two-times more MD than those of type 2B. The vascular access device most commonly used was a single lumen catheter (80.6 % of infusion methods). 100 % of the hospitals having answered used multi-access devices (three-way tap, multiport infusion manifold, Y-extension lines) and 93.5 % used a pump-infusor. Lipidic filters for parenteral nutrition were used in 78.6 % of the hospitals. Two general standard of infusion methods were isolated: a simple version with two access points (type 2B hospitals), and a complex one with five access points (from hospitals with type 3 maternities).

CONCLUSIONS

Neonatal infusion practices in France are very heterogeneous, thus exposing the patients to a degree of variability during their therapeutic management. This work is a first step forwards to help analyse and anticipate the risks of content/container interactions caused by infusion practices.

Understanding and Characterizing the Drug Sorption to PVC and PE Materials

Characterizing the sorption of drugs onto polyvinylchloride (PVC) and polyethylene (PE) materials in terms of thermodynamic adsorption properties and atomistic details (local arrangements, orientation, and diffusion) is fundamental for the development of alternative materials that would limit drug sorption phenomena and plasticizer release. Here, a combination of experiments and sophisticated calculations of potential of mean forces are carried out to investigate the sorption of paracetamol and diazepam to PE and PVC surfaces. The simulated Gibbs free energies of adsorption are in line with the experimental interpretations. The polymer-drug-water interface is then characterized at the molecular scale by an in-depth investigation of local properties such as density, orientation, and diffusion.

An update on the hazard of and exposure to diethyl hexyl phthalate (DEHP) alternatives used in medical devices

The use of the plasticizer diethyl hexyl phthalate (DEHP) in PVC medical devices is being questioned due to its potential reprotoxic effects in patients exposed as a result from migration from the device. This article reviews new information on migration and toxicity data of eleven alternative plasticizers that have previously been evaluated by the Danish EPA and the EU SCENIHR (Scientific Committee on Emerging and Newly Identified Health Risks). The new toxicity data did not justify the reconsideration of the critical NOAELs as established by SCENIHR and Danish EPA. The dataset on oral toxicity studies is rather complete for most substances; however, in particular for reproductive toxicity and endocrine disruption, data gaps still exist for many alternatives. Toxicity data on intravenous exposure are lacking and these are essential to conclude on hazard characteristics of alternatives that are poorly absorbed via the oral exposure route. Migration data are emerging for a few alternatives but still sparse for the majority of the alternatives. Taking all data on migration and toxicity in consideration, 1,2-cyclohexanedicarboxylic acid, diisononylester (DINCH), and tris(2-ethylhexyl)benzene-1,2,4-tricarboxylate display a more favorable profile compared to DEHP. For these promising alternatives, a risk assessment for use in medical devices should be conducted. As a next step, we recommend the (further) generation of relevant migration data and, where needed, relevant toxicity data for the alternative substances, in order to be able to conduct a benefit-risk analysis of DEHP and the alternatives as obligatory in the new European Union Medical Device Regulation.

Impact of alternative materials to plasticized PVC infusion tubings on drug sorption and plasticizer release

Medical tubings in plasticized polyvinylchloride (PVC) are widely used for the infusion of medications but are known in some cases to cause content-container interactions (drug sorption and plasticizer release). The aim of this study was to assess interactions between drugs and five alternative materials to a reference plasticized PVC intravenous (IV) infusion tubing: three were PVC coextruded with polyethylene (PE), polyurethane (PU) or a thermoplastic elastomer (Styrene-EthyleneButadiene-Styrene (SEBS)) and two were SEBS or thermoplastic olefin (TPO) monolayer tubings. Diazepam and insulin were chosen as respective reference of absorption and adsorption while paracetamol acted as a negative control. The concentration of each drug was quantified with liquid chromatography to evaluate a potential loss after a static contact condition and simulated infusion at 1 mL/h and 10 mL/h dynamic condition by an electric syringe pump. A characterization of each material's surface was performed by Fourier transform infrared spectroscopy in attenuated total reflection mode (ATR-FTIR) and by measurement of surface zeta potential. Plasticizer release was quantified by gas chromatography coupled with mass spectrometry (GC-MS). For all tubings except PVC/PU, no loss of paracetamol was observed in any condition. Diazepam sorption appeared to be less important with PVC/PE, PVC/SEBS, SEBS and TPO tubings than with PVC, but was more important when using PVC/PU tubings. PVC tubings induced the least loss of insulin amongst all the studied materials. Surface analysis by ATR-FTIR highlighted the presence of a plasticizer (that could be attributed to Tris (2-Ethylhexyl) Trimellitate (TOTM)) in the coextruded SEBS layer of PVC/SEBS, which could have influenced drug sorption, probably as a consequence of a migration from the PVC layer. Coextruded PVC/SEBS and PVC/PE presented the lowest zeta potential of all studied materials with respective values of -39 mV and -36 mV and were related to the highest sorption of insulin while PVC/PU with the highest zeta potential (about -9 mV) presented the highest absorption of diazepam. Coextruded layered materials appeared to have a lower plasticizer release than PVC alone. As a conclusion, PVC/PE and thermoplastic elastomers alone or coextruded with PVC could be interesting alternatives to PVC tubings with regards to sorption phenomena and plasticizer release.

In vitro assessment of the influence of intravenous extension set materials on insulin aspart drug delivery

Insulin is a frequently prescribed drug in hospitals and is usually administered by syringe pumps with an extension line which can be made of various materials. Two insulin solutions were studied: an insulin analogue, Novorapid^® which contains insulin aspart and two phenolic preservatives (e.g. phenol and metacresol) and Umuline rapide^® with human insulin and metacresol as preservative. Some studies have indicated interactions between insulin, polyvinyl chloride (PVC) and polyethylene (PE). The aim of this work was to study such interactions between Novorapid^® or Umuline rapide^® and infusion extension line materials (PVC, PE and coextruded (PE/PVC)). Insulin solution at 1 IU/mL was infused at 2 mL/h over 24 hours with 16 different extension lines (8 in PVC, 3 in PE and 5 in PE/PVC). Ultra-Fast Liquid Chromatography with diode array detection (UFLC-DAD) was performed to quantify insulin (human and aspart) and preservatives (metacresol and phenol). Limited human insulin sorption was observed thirty minutes after the onset of infusion: 24.3 ± 12.9%, 3.1 ± 1.6% and 18.6 ± 10.0% for PVC, PE and PE/PVC respectively. With insulin aspart, sorption of about 5% was observed at the onset of infusion for all materials. However, there were interactions between phenol and especially metacresol with PVC, but no interactions with PE and PE/PVC. This study shows that insulin interacts with PVC, PE and PE/PVC at the onset of infusion. It also demonstrates that insulin preservatives interact with PVC, which may result in problems of insulin conservation and conformation. Some more studies are required to understand the clinical impact of the latter during infusion.

Assessment of Patient Exposure to Leachables From Lyophilized Drug Formulations Following Reconstitution, Storage, and Administration via Polymeric Packaging/Delivery Systems

It has been demonstrated that lyophilized drug formulations have an increased propensity to leach substances from the rubber stoppers comprising their primary packaging system when compared to aqueous liquid formulations stored in the same manner. Unfortunately, patient exposure to leachables originating in lyophilized drug products is not known. To that end, the goal of this study was to assess patient exposure to these leachables after reconstitution, storage, and administration of the lyophilized drug. To achieve this goal, several leachables present in 2 commercial lyophilized drug products were quantified after contact with polyvinyl chloride and non-polyvinyl chloride medication bags as well as an infusion set for durations of 15 min to 7 days at refrigerated and ambient temperature. The results obtained from this study showed that the bag's material of construction and the drugs formulation did not impact the mass of the leachables administered. Conversely, the mass of each leachable administered to the patient was reduced or eliminated as the contact duration with the intravenous bag and the temperature increased. However, for shorter contact durations, refrigerated storage, and higher molecular weight compounds, the patient would be exposed to a majority of the leachables originating from the vial.

A comparison of the pharmacokinetic and pharmacodynamic properties of nitroglycerin according to the composition of the administration set: A preliminary study

BACKGROUND

There is a risk of drug sorption into an intravenous administration set composed of polyvinyl chloride (PVC), polyurethane (PU), or polyolefin (PO). This has implications on the dose of the active ingredient the patient receives, and thus therapeutic success. This study aimed to determine the plasma concentration of nitroglycerin and the effect of nitroglycerin on patients based on the composition of the administration set.

METHODS

Using a randomized, open-labeled, 3 × 3 crossover method, 9 volunteers were assigned to 3 groups. In period I, nitroglycerin (100 μg/mL) was infused via a PVC- (group A), PU- (group B), or PO-based (group C) administration set. In period II, PU- (group A), PO- (group B), and PVC-based (group C) administration sets were used, and in period III, PO- (group A), PVC- (group B), and PU-based (group C) administration sets were used. The rate of drug administration in all periods was 12 mL/hour for 30 minutes using an infusion pump. Blood samples were collected, and the plasma concentrations of nitroglycerin were analyzed using validated high-performance liquid chromatography coupled with tandem mass spectrometry. Blood pressure was determined using a sphygmomanometer applied to the other upper arm at an interval of 5 minutes.

RESULTS

We observed that the mean plasma concentration of nitroglycerin over time when administered using a PO-based tube was higher than that when using a PU- or PVC-based tube. When the percent change of the mean arterial pressure from baseline at each time point was compared among groups, there were statistically significant differences between PU and PO or PVC at most points during nitroglycerin infusion.

CONCLUSION

Our results showed higher nitroglycerin plasma concentration and lower arterial pressure when a PO-based administration set was used than when a PVC- or PU-based administration set was used. PO-based administration sets may be more appropriate for nitroglycerin administration compared to those composed of PVC or PU.

Criteria for choosing an intravenous infusion line intended for multidrug infusion in anaesthesia and intensive care units

OBJECTIVE

The aims are to identify critical parameters influencing the drug mass flow rate of infusion delivery to patients during multidrug infusion and to discuss their clinical relevance.

DATA SOURCES

A review of literature was conducted in January 2016 using Medline, Google Scholar, ScienceDirect, Web of Science and Scopus online databases.

DATA EXTRACTION

References relating to the accuracy of fluid delivery via gravity-flow intravenous (IV) infusion systems and positive displacement pumps, components of IV administration sets, causes of flow rate variability, potential complications due to flow rate variability, IV therapies especially at low flow rates and drug compatibilities were considered relevant.

DATA SYNTHESIS

Several parameters impact the delivery of drugs and fluids by IV infusion. Among them are the components of infusion systems that particularly influence the flow rate of medications and fluids being delivered. By their conception, they may generate significant start-up delays and flow rate variability. Performing multidrug infusion requires taking into account two main points: the common dead volume of drugs delivered simultaneously with potential consequences on the accuracy and amount of drug delivery and the prevention of drug incompatibilities and their clinical effects.

CONCLUSION

To prevent the potentially serious effects of flow rate variability on patients, clinicians should receive instruction on the fluid dynamics of an IV administration set and so be able to take steps to minimise flow rate changes during IV therapy.

Influence of a Double-Lumen Extension Tube on Drug Delivery: Examples of Isosorbide Dinitrate and Diazepam

Purpose

Plastic materials such as polyurethane (PUR), polyethylene (PE), polypropylene (PP) and polyvinyl chloride (PVC) are widely used in double-lumen extension tubing. The purposes of our study were to 1) compare in vitro drug delivery through the double extension tubes available on the market 2) assess the plastic properties of PUR in infusion devices and their impact on drug delivery.

Methods

The study compared eight double-lumen extension tubes in PUR, co-extruded (PE/PVC) plastic and plasticised PVC from different manufacturers. Isosorbide dinitrate and diazepam were used as model compounds to evaluate their sorption on the internal surface of the infusion device. Control experiments were performed using norepinephrine known not to absorb to plastics. Drug concentrations delivered at the egress of extension tubes were determined over time by an analytical spectrophotometric UV-Vis method. The main characteristics of plastics were also determined.

Results

Significant differences in the sorption phenomenon were observed among the eight double-lumen extension tubes and between pairs of extension tubes. Mean concentrations of isosorbide dinitrate delivered at the egress of double-lumen extension tubes after a 150-minute infusion (mean values ± standard deviation in percentage of the initial concentrations in the prepared syringes) ranged between 80.53 ± 1.66 (one of the PUR tubes) and 92.84 ± 2.73 (PE/PVC tube). The same parameters measured during diazepam infusion ranged between 48.58 ± 2.88 (one of the PUR tubes) and 85.06 ± 3.94 (PE/PVC tube). The double-lumen extension tubes in PUR were either thermosetting (resin) or thermoplastic according to reference.

Conclusions

Clinicians must be aware of potential drug interactions with extension tube materials and so must consider their nature as well as the sterilisation method used before selecting an infusion device.