Nicolas Simon

Impact of multiaccess infusion devices on in vitro drug delivery during multi-infusion therapy.

BACKGROUND: Multiaccess infusion sets allow multiple simultaneous infusions but may induce interference in drug delivery resulting from large variations in the delivery rate of potent drugs. In this study, we sought to understand the influence of multiaccess infusion device properties (dead space volume and antireflux valve [ARV]) on drug delivery during multi-infusion therapy. METHODS: Infusion sets differing in length, dead space volume, and presence of an ARV were assessed. Three drugs were infused simultaneously through different access points, and their concentrations were obtained using UV spectrophotometric analysis of the effluent. Different infusion configurations were compared by assessing (1) the amount of drug delivered to the patient per unit of time, (2) the mean amount of drug delivered to the patient per unit of time during the steady-state infusion (mass flow rate plateau), and (3) flow change efficiency calculated from the ratio of the area under the experimental instant mass flow rate curve to the area corresponding to theoretical instant mass flow rate curve. RESULTS: Infusion sets with lower dead space volumes offered significantly higher flow change efficiency (53.0% ± 15.4% with a dead space volume equal to 0.046 mL 5 min after the start of infusion) than infusion sets with higher dead space volume (5.6% ± 8.2% with a dead space volume equal to 6.16 mL), whatever the flow rate changes. Even in case of large dead space volumes, the presence of an ARV significantly increased the mass flow rate plateau (from 92.4% to 99.3% of the theoretical plateau without and with the presence of an ARV, respectively). CONCLUSIONS: Multi-infusion therapy induces perturbation in drug delivery. These perturbations (lag time, backflow, and bolus) could be reduced by using infusion sets including very low dead space volume and an ARV.

Infusion set characteristics such as antireflux valve and dead-space volume affect drug delivery: an experimental study designed to enhance infusion sets.

BACKGROUND: The ability of an infusion set to deliver a specific amount of drug to the patient can be directly related to the presence of an antireflux valve and dead-space volume. In this study we quantified separately the impact of these 2 components on drug delivery. METHODS: Various infusion sets were assessed differing in length, in dead-space volume, and with or without an antireflux valve. Noradrenalin was infused with a syringe pump simultaneously with a carrier flow. Effluent drug concentration was measured using ultraviolet spectrophotometry. Flow change efficiency (FCE) was calculated from the ratio of the area under the experimental mass flow rate curve to the area under the theoretical instantaneous mass flow rate curve. RESULTS: The FCE for infusion sets with or without antireflux valves were significantly different 10 to 15 minutes after the start of an infusion at flow rates of 7 mL/h for noradrenalin and 35 mL/h to 70 mL/h for the carrier fluid. They were not different with a carrier flow of 115 mL/h. DISCUSSION: These findings suggest that antireflux valves have a significant impact on FCE when the ratio of drug flow rate to carrier fluid flow rate is high. Infusion sets with very low dead-space volume connectors yield better FCE. There is a nonlinear relationship between dead-space volume and FCE 5 to 10 minutes after the onset of drug infusion. CONCLUSION: Care providers must consider dead-space volume and the presence of an antireflux valve when choosing their infusion sets.

The impact on drug mass flow rate of interrupting and resuming carrier fluid flow: an in vitro study on a very low dead-space volume infusion set.

BACKGROUND: Stopping and resuming carrier fluid flow can lead to potentially dangerous transient disturbances in drug mass flow rate. We compared the impact of 2 infusion sets, one with very low dead-space volume and the other with greater dead-space volume, on the amount of drug delivered during stop-and-go carrier fluid flows. METHODS: Two infusion sets, both with antireflux, connected to an angiocatheter and with dead-space volumes of 6.185 mL and 0.071 mL, respectively, were assessed. Two protocols were studied: carrier fluid flow of 90 mL/h associated with noradrenaline infused at 7 mL/h and carrier fluid flow of 350 mL/h with a noradrenaline infusion flow of 65 mL/h. During both protocols, the carrier fluid was stopped and resumed at the same rate 30 minutes later. Effluent noradrenaline concentration was measured using UV spectrophotometry. Flow change efficiency was calculated from the ratio of the area under the experimental mass flow rate curve to the area under the theoretical instantaneous mass flow rate curve. RESULTS: For both flow rate conditions, flow change efficiency was significantly different for the 2 infusion sets during the 10-minute period after stopping carrier fluid flow and the 10-minute period after restarting it. The major phenomena were sudden decreases in drug delivery after stopping carrier flow and sudden, temporary increases when it was resumed. The very low dead-space volume infusion set resulted in significant reduction in changes in drug delivery compared with the standard set, even at high flow rates. CONCLUSION: The use of a very low dead-space volume set attenuates disturbances in drug delivery caused by interrupting and resuming carrier fluid flow.

A chemometric approach to elucidate the parameter impact in the hyphenation of evaporative light scattering detector to supercritical fluid chromatography.

The aim of this work was to elucidate the effects of parameters influencing the evaporative light scattering detector (ELSD) response when it was coupled to supercritical fluid chromatography (SFC). Phthalates, currently used as plasticizers in medical devices, were selected as model compounds. The configuration of the hyphenation setup was firstly optimized and shown that both peak efficiency and sensitivity were improved by connecting the ELSD to the SFC before the back pressure regulator (BPR). By using a tee-junction which splits the flow after the PDA towards the collect fraction (or waste) and the ELSD, this instrument configuration has the advantage to be applicable for small-scale preparative SFC. The impacts of other parameters such as mobile phase composition and flow rate, outlet pressure, column oven temperature and ELSD drift tube temperature on the ELSD signal were evaluated using a chemometric approach. First, it was demonstrated that a classical mobile phase composed of CO2-methanol 90:10 (v/v) was suitable to obtain great nebulization efficiency. The flow rate of the eluent was the second main effect factor. The setting must be as low as possible to avoid the loss of large particle size in the drift tube resulting in a loss of signal intensity. Concerning the outlet pressure, the configuration of the setup between SFC and ELSD requires a setting as high as possible to limit the partial liquid-vapor separation of the mobile phase in the restrictor tube. Finally, due to the low quantity of solvent which must be evaporated in the detector, a drift tube temperature of 25 °C is suitable for the hyphenation of ELSD to SFC. In the optimized conditions, the proposed SFC/ELSD method could be suitable to quantify plasticizers in medical devices.

Quantification of five plasticizers used in PVC tubing through high performance liquid chromatographic-UV detection.

Searching for alternatives to di-(2-ethylhexyl)-phthalate, a plasticizer that has been widely used in the manufacturing of PVC medical devices, has become a major challenge since a European regulation underlined some clinical risks. The aim of this study is to develop an HPLC-UV method to quantify the currently used alternative plasticizers to DEHP. Five plasticizers, acetyl tributyl citrate, di-(2-ethylhexyl)-phthalate, di-(ethylhexyl)-terephthalate, di-isononyl-1,2-cyclohexane-dicarboxylate, and trioctyl trimellitate, were separated on a C8 stationary phase (2.6 μm, 100 mm × 4.6mm) under gradient elution in 13 min. They were detected at 221 nm leading to a quantification threshold from 0.3 to 750 μg/mL as a function of the plasticizer. Within-day and between-day precisions were inferior to 0.9% and 18%, respectively. The assays were validated according to the accuracy profile method. Plasticizers were extracted from PVC-tubing by dissolving PVC in THF then precipitating it in methanol with a yield of over 90% for each plasticizer. This assay could feasibly be used to quantify plasticizers in PVC medical devices.

Poly‐cyclodextrin functionalized porous bioceramics for local chemotherapy and anticancer bone reconstruction

The progress in bone cancer surgery and multimodal treatment concept achieve only modest improvement in the overall survival, due to failure in clearing out residual cancer cells at the surgical margin and extreme side-effects of adjuvant postoperative treatments. Our study aims to propose a new method based on cyclodextrin polymer (polyCD) functionalized hydroxyapatite (HA) for achieving a high local drug concentration with a sustained release profile and a better control of residual malignant cells via local drug delivery and promotion of the reconstruction of bone defects. PolyCD, a versatile carrier for therapeutic molecules, can be incorporated into HA (bone regeneration scaffold) through thermal treatment. The parameters of polyCD treatment on the macroporous HA (porosity 65%) were characterized via thermogravimetric analysis. Good cytocompatibility of polyCD functionalized bioceramics was demonstrated on osteoblast cells by cell vitality assay. An antibiotic (gentamicin) and an anticancer agent (cisplatin) were respectively loaded on polyCD functionalized bioceramics for drug release test. The results show that polyCD functionalization leads to significantly improved drug loading quantity (30% more concerning gentamicin and twice more for cisplatin) and drug release duration (7 days longer concerning gentamicin and 3 days longer for cisplatin). Conclusively, this study offers a safe and reliable drug delivery system for bioceramic matrices, which can load anticancer agents (or/and antibiotics) to reduce local recurrence (or/and infection).

Effectiveness of a Closed-System Transfer Device in Reducing Surface Contamination in a New Antineoplastic Drug-Compounding Unit: A Prospective, Controlled, Parallel Study.

Background The objective of this randomized, prospective and controlled study was to investigate the ability of a closed-system transfer device (CSTD; BD-Phaseal) to reduce the occupational exposure of two isolators to 10 cytotoxic drugs and compare to standard compounding devices. Methods and Findings The 6-month study started with the opening of a new compounding unit. Two isolators were set up with 2 workstations each, one to compound with standard devices (needles and spikes) and the other using the Phaseal system. Drugs were alternatively compounded in each isolator. Sampling involved wiping three surfaces (gloves, window, worktop), before and after a cleaning process. Exposure to ten antineoplastic drugs (cyclophosphamide, ifosfamide, dacarbazine, 5-FU, methotrexate, gemcitabine, cytarabine, irinotecan, doxorubicine and ganciclovir) was assessed on wipes by LC-MS/MS analysis. Contamination rates were compared using a Chi2 test and drug amounts by a Mann-Whitney test. Significance was defined for p<0.05. Overall contamination was lower in the “Phaseal” isolator than in the “Standard” isolator (12.24% vs. 26.39%; p < 0.0001) although it differed according to drug. Indeed, the contamination rates of gemcitabine were 49.3 and 43.4% (NS) for the Standard and Phaseal isolators, respectively, whereas for ganciclovir, they were 54.2 and 2.8% (p<0.0001). Gemcitabine amounts were 220.6 and 283.6 ng for the Standard and Phaseal isolators (NS), and ganciclovir amounts were 179.9 and 2.4 ng (p<0.0001). Conclusion This study confirms that using a CSTD may significantly decrease the chemical contamination of barrier isolators compared to standard devices for some drugs, although it does not eliminate contamination totally.

Technical evaluation of a new sterile medical device to improve anticancer chemotherapy administration.

PURPOSE/OBJECTIVES To assess the PCHIMX-1 (Doran International), a new sterile medical device intended by its manufacturer to improve the quality and safety of cytotoxic drug infusions, as well as its influence on manipulation times required for pharmacy technicians and nurses and its effect on infusion line outflow parameters. DESIGN PCHIMX-1 assemblies were compared to standard infusion sets. SETTING Pharmacy and oncology units of a French general hospital. METHODS Reference assemblies (an infusion bag connected to an infusion set) were compared to PCHIMX-1 assemblies (PCHIMX-1 connected to two bags and to an infusion set). Two assessments were performed: (a) comparison of the times of manipulation during both preparation and administration of 5-fluorouracil infusion bags (n = 40) and (b) effect of PCHIMX-1 on infusion quality. MAIN RESEARCH VARIABLES Manipulation times in the pharmacy (TP) and in the ward (TW) were measured, as well as flow rate and infusion efficiency. FINDINGS The results showed that TW was significantly increased, whereas TP was significantly decreased; total time was unchanged. Results also showed that PCHIMX-1 significantly changed infusion efficiency; flow rate was not affected. CONCLUSIONS PCHIMX-1 obliges pharmacy technicians and nurses to change their handling procedures. The device does not have any influence on infusion flow rate but considerably improves infusion quality by ensuring that the full quantity of medication prescribed is administered. IMPLICATIONS FOR NURSING PCHIMX-1 guarantees that the complete prescribed dose of chemotherapy is administered without any change in infusion quality and adheres to the latest recommendations concerning occupational exposure protection.

How to solve the problem of co-elution between two compounds in liquid chromatography through the first UV derivative spectrum. A trial on alternative plasticizers to di(2-ethylhexyl) phthalate

To meet new regulations, alternative plasticizers to di(2-ethylhexyl) phthalate (DEHP) are now commonly used in the manufacturing of medical devices. These are: acetyl tri-n-butyl citrate (ATBC), bis (2-ethylhexyl)adipate (DEHA), dioctyl terephtalate (DEHT), di-isononylphtalate (DINP), diisononylcyclohexane-1.2-dicarboxylate (DINCH) and trioctyltrimellilate (TOTM). An HPLC-UV analysis was previously developed to characterize four of them. However, two compounds were systematically co-eluated: DEHP with DEHA and DEHT with DINP. The first derivative of UV spectra and photodiode array detection allow the quantification of DEHA and DINP. Moreover, for each plasticizer, maximum wavelength absorbance was chosen to be as specific as possible. Quantification ranged from 0.3 to 750µg/mL according to the plasticizer. The assays were validated by analysis of variance. Our method was validated by determining the following parameters: specificity, linearity, limits of detection and quantification. The relative biases were inferior to 5% for ATBC, DEHP, DEHA and DINCH and inferior to 10% for DEHT, DINP and TOTM. Plasticizers were extracted with tetrahydrofuran and methanol. The developed method was then used to determine the composition of plasticizers in several medical devices used in clinical service. The major plasticizers were quantified from 19% to 40% w/w, traces of DEHT were found in six medical devices and DEHP in five.

Pediatric Patients With Solid or Hematological Tumor Disease: Vancomycin Population Pharmacokinetics and Dosage Optimization.

Background: In pediatric cancer patients, determination of optimal vancomycin dosage is essential because of high risk of inadequate concentrations and bacterial resistance. The aim of this study was to determine vancomycin pharmacokinetic parameters in this population and propose dosage optimization to achieve optimal concentration. Methods: We retrospectively reviewed the use of vancomycin in pediatric cancer patients with febrile neutropenia (hematological or solid tumor disease). Vancomycin was administered by continuous infusion, and dosages were adapted according to therapeutic drug monitoring results. Blood cultures were performed before the first dose of antibiotic. Vancomycin pharmacokinetic population parameters were determined using NONMEM software, and dosage simulations were performed according to the target concentration (20–25 mg/L). Results: One hundred twenty-one patients were included in this study, representing 301 vancomycin concentrations. Blood cultures were positive in 37.5% of patients, and observed pathogens were mainly Staphylococcus spp. (43.8% methicillin resistant). Volume of distribution (95% confidence interval) was 34.7 L (17.3–48.0), and total apparent clearance (CL) (95% confidence interval) was correlated to body weight, tumor disease, and cyclosporine coadministration: CL = &thgr;CL × (WT/70)0.75 L/h with &thgr;CL = 3.49 (3.02–3.96), 4.66 (3.98–5.31), and 4.97 (4.42–5.41) in patients managed for hematological malignancies with or without cyclosporine coadministration and for solid malignancies, respectively. Based on simulation results, vancomycin dosage (milligram per kilogram) should be adapted to each child on the basis of its body weight and cyclosporine coadministration. Conclusions: Our results highlight the requirement to adapt vancomycin dosage in cancer pediatric population. Simulations have allowed to describe new dosage schedules, and a chart was created for clinicians to adapt vancomycin dosage.