Physicochemical Stability of Hospital Parenteral Nutrition Solutions: Effect of Changes in Composition and Storage Protocol

(1) Background: Parenteral nutrition (PN) is a technique used for the administration of nutrients to patients for whom traditional routes cannot be used. It is performed using solutions with extremely complex compositions, which can give rise to a large number of interactions. These interactions can impact their stability and put the patient's life at risk. The aim of this study is to determine how changes in composition and storage protocol affect the stability of NP solutions. (2) Methods: Twenty-three samples were prepared according to routine clinical practice, with modifications to the concentration of some components. The samples were stored at room temperature (RT) and refrigerated (4 °C). Measurements of the droplet diameter, pH, density and viscosity were performed for both storage protocols on days 1, 3, 10 and 14. (3) Results: The samples with the lowest concentration of lipids (PN13-17) and proteins (PN18-22) showed a larger droplet diameter than the rest of the samples throughout the experiments. The USP limits were exceeded for some of the measurements of these sample groups. The pH density and viscosity remained relatively constant under the conditions studied. (4) Conclusions: The PN samples were considered stable and safe for administration under real-world conditions, but the samples with the lowest concentrations of lipids and proteins showed a tendency towards emulsion instability.

Stability of lipid emulsion in total parenteral nutrition: An overview of literature

BACKGOUND AND AIMS

Total parenteral nutrition (TPN) is an extremely complex mixture. The multitude of chemical compounds involved can give rise to numerous reactions that condition its stability. We set out to review the existing literature on different issues related to stability, and which are still of concern in the hospital environment; such as the stability of the lipid emulsion. In addition, we analyse other related factors and parameters that allow us to predict the stability of TPN based on the composition.

MATERIAL AND METHODS

we searched PubMed and Google Scholar, over the date range 1995-2019 for relevant studies about TPN stability. We included experimental studies where the physical stability of the lipid emulsion in TPN had been analysed. We applied specific exclusion criteria.

RESULTS

we included 20 papers in this review of TPN stability. The studies combined different analytical techniques to assess the stability. In all the studies, the mean droplet diameter (MDD) is measured and the stability analysis is completed with other measurements. Temperature and components concentration are also considered.

CONCLUSIONS

studies on the stability of TPN used differing components with different chemical characteristics and their results can be difficult to extrapolate. There is no clear consensus about the composition of the mixtures and there is also great variety in the analytical techniques that were used to analyse stability. It is necessary to conduct new studies to update information on TPN stability.

Physicochemical Stability and Compatibility Testing of Voriconazole in All-in-One Parenteral Nutrition Admixtures

(1) Drug compatibility with all-in-one (AiO) parenteral nutrition (PN) admixtures is a very important pharmaceutical quality issue to be answered based on appropriate laboratory testing. We assessed voriconazole (V), a poorly water-soluble (logP ≈ 1) single-daily dosed antifungal drug monitored in patients and thus candidate for AiO PN admixing for convenient and safe patient care. We evaluated V compatibility and stability in AiO PN admixtures through adapted therapeutic drug monitoring method (drug stability) and visual microscopic emulsion stability by lipid droplets analysis improved by an automated microscopic digital assessment. (2) V was added in concentrations of 0.05/0.25/0.5 mg/mL (143.1/715.7/1431.5 µM), correlating to daily therapeutic dosing, to three commercially available industrial AiO PN admixtures. Three aliquots were stored in the refrigerator (4 °C), at room temperature (24 °C) and under stress conditions in a water bath (37 °C). Samples taken at 0/24/48/72/168 h after admixing were subjected to a stability-indicating one-week analysis. Assessment included visual examination, lipid droplet measurement according to an established and validated method (bright-field microscopy using oil immersion), pH measurement (glass electrode) and V identification/quantification (LC–MS/MS). (3) After one week, all samples at 37 °C showed slight yellow discoloration. The pH values remained stable. All samples met specifications for lipid droplets according to size (upper size ≤8 µm, mean size <4.5 ± 2 µm) and number (n ≤ 9 lipid droplets >5 µm). V concentrations were within an acceptable range, calculated for every timepoint as percent of the theoretical concentration spiked into the AiO PN. The median recovery was 98.2% (min–max, 90–112%). (4) At therapeutic doses, commercial V formulations were compatible and stable within specifications over one week in commonly used volumes of commercial AiO PN admixtures at 4–37 °C.

All-in-One Pediatric Parenteral Nutrition Admixtures with an Extended Shelf Life-Insight in Correlations between Composition and Physicochemical Parameters

The administration of three-in-one parenteral nutrition (PN) admixtures to pediatric patients requires special consideration, specifically concerning quality and physicochemical stability. The introduction of a new parenteral amino acid solution into the market prompted us to evaluate Aminoplasmal Paed-based PN admixtures’ stability. The study aimed to determine the physicochemical parameters of the chosen variations of PN admixtures and search for a correlation between its composition and those parameters. One hundred and sixty-eight variations of PN admixtures intended for patients weighing from 10 to 25 kg and aged from 1 to 12 years and differing in the quantitative composition of electrolytes were selected for the study. The samples were prepared using each of the four intravenous lipid emulsions dedicated to pediatric patients: Intralipid 20%, Clinoleic 20%, Lipidem 20%, and Smoflipid 20%. The stability of the PN admixtures was assessed by visual inspection and determination of pH, osmolality, zeta potential, and hydrodynamic mean droplet diameter (MDD) immediately upon preparation and after seven days of storage at the temperature of 5 ± 1 °C with light protection. Pearson’s correlation was used to quantify the relationships between selected ingredients of the PN admixtures and the physicochemical parameters. The PN admixtures were characterized by pH ranging from 5.91 to 7.04, osmolality ranging from 1238 to 1678 mOsm/kg, and zeta potential ranging from −41.3 to −2.16 mV. The changes in pH and osmolality after seven days of storage did not exceed 0.2 and 4.4%, respectively. The homogeneity of the PN admixtures was confirmed by determining the polydispersity index, which ranged from 0.06 to 0.2. The MDD of the studied formulas ranged from 235 to 395 nm and from 233 to 365 nm immediately upon preparation and after the storage period, respectively. Correlations between selected components of the PN admixtures and some physicochemical parameters were found. All Aminoplasmal Paed 10%-based PN admixtures were characterized by appropriate physicochemical quality to be administered via the central veins, both immediately upon preparation and after seven days of storage at the temperature of 5 ± 1 °C with light protection. The applied electrolyte concentrations ranges and types of lipid emulsions in the selected macronutrient quantitative compositions allowed the PN admixtures to remain stable for seven days within the specified limits.

Use of Intravenous Lipid Emulsions With Parenteral Nutrition: Practical Handling Aspects

A number of topics important to the handling of intravenous lipid emulsions (ILEs) were discussed at the international summit. ILE handling includes the preparation and the administration steps in the typical use of parenteral nutrition (PN). The discussion and consensus statements addressed several issues, including standardization of the PN process, use of commercially available multi-chamber PN or compounded PN bags, the supervision by a pharmacist with expertise, limiting ILE repackaging, and infusion duration.

Stability studies of parenteral nutrition with a high dose of vitamin C

BACKGROUND

Postoperative administration of parenteral nutrition has become routine management in patients with gastrointestinal cancer. Providing patient the complete parenteral nutrition containing not only the macronutrients and electrolytes but also adequate doses of vitamins is a significant issue of nutritional therapy. The aim of the study was to develop parenteral nutrition containing a high dose of vitamin C (500 mg) and evaluate their stability.

METHODS

Five compositions of parenteral nutrition were developed and stored for seven days in three different conditions. Physical stability studies including visual examination and determination of pH, size of lipid droplets (using dynamic laser scattering method), and zeta potential (using laser Doppler electrophoresis method) were performed for all studied parenteral nutrition with and without vitamin C immediately after preparation and after storage. The content of vitamin C was determined using high-performance liquid chromatography (HPLC) method.

RESULTS

The addition of vitamin C to parenteral nutrition did not affect its physical stability. Degradation of vitamin C in parenteral nutrition occurred according to first-order kinetics reaction. The content of vitamin C remained above 90% of zero-time content within the first 24 h for each studied parenteral nutrition compositions stored at 4°C and 25°C with light protection.

CONCLUSIONS

Vitamin C added to parenteral nutrition was unstable regardless of the storage conditions nor parenteral nutrition compositions. However, for the first 24 h, the content of vitamin C remained in the pharmacopoeial limit. Therefore, supplementation of parenteral nutrition admixtures with vitamin C in the dose of 500 mg is possible in the condition of administration to the patients within the first 24 h.

Hemofilter Obstruction with Intravenous Lipid Administration

A critically ill patient requiring continuous venovenous hemofiltration therapy received parenteral nutrition through the same commonly used intravascular device. The inclusion of injectable lipid emulsion had an adverse effect on hemofilter function. This was successfully managed first by using lipid-free parenteral nutrition and then by administering the total nutrient admixture via a separate central venous access device.

Physicochemical stability and compatibility testing of levetiracetam in all-in-one parenteral nutrition admixtures in daily practice

BACKGROUND

Parenteral antiepileptic drugs are frequently used in critically ill patients for seizure control therapy or prevention. Many of these patients require additional parenteral nutrition (PN). Therefore, a parallel infusion of the frequently used antiepileptic drug levetiracetam (LEV) is interesting in terms of the restricted i.v. lines (e.g., neonates). The potential interactions of the complex PN admixture with the drug product and the appropriate admixing of a drug at effective dosages require physicochemical lab assessments to obtain specific and reliable pharmaceutical documentation for the intended admixing.

AIM

To assess the of compatibility and stability of LEV, a neutral and hydrophilic drug, in commercial all-in-one (AiO) PN admixtures using simple validated tests to provide necessary data in a timely manner and to allow convenient, documented and safe treatment with PN as the drug vehicle.

METHODS

Different concentrations of LEV were injected into two different AiO PN admixtures with no further additives. Stability and compatibility tests for the drug and the PN admixtures were performed over seven days at +4°C, +23±1°C and +37°C without light protection. Stability and sample characteristics were observed by visual inspection and the validated light microscope method. Moreover, the pH level of the admixture was checked, as were the concentrations of LEV over time in the PN admixtures, using an established LC-MS/MS method.

RESULTS

The stability controls of LEV at different temperatures were within absolute ±20% of the theoretical value in a concentration range of 98.91-117.84% of the initial value. No changes in pH occurred (5.55±0.04) and no microscopic out of specification data or visual changes were observed. The mean value of the largest lipid droplet in each visual field over seven days was 2.4±0.08μm, comparable to that of the drug-free AiO admixture. Samples stored at +37°C showed yellowish discolorations after 96h of storage.

CONCLUSION

LEV showed compatibility and stability over seven days in the selected PN admixtures, and the described methods represented a valuable and timely approach to determine the stability and compatibility of the highly hydrophilic, not dissociated LEV in AiO admixtures under conditions of use. Further studies with clinically relevant and representative examples of physicochemically different drug classes are needed.

Development and evaluation of a test program for Y-site compatibility testing of total parenteral nutrition and intravenous drugs

Background

There is no standardized procedure or consensus to which tests should be performed to judge compatibility/incompatibility of intravenous drugs. The purpose of this study was to establish and evaluate a test program of methods suitable for detection of physical incompatibility in Y-site administration of total parenteral nutrition (TPN) and drugs.

Methods

Eight frequently used methods (dynamic light scattering, laser diffraction, light obscuration, turbidimetry, zeta potential, light microscopy, pH-measurements and visual examination using Tyndall beams), were scrutinized to elucidate strengths and weaknesses for compatibility testing. The responses of the methods were tested with samples containing precipitation of calcium phosphate and with heat destabilized TPN emulsions. A selection of drugs (acyclovir, ampicillin, ondansetron and paracetamol) was mixed with 3-in-1 TPN admixtures (Olimel® N5E, Kabiven® and SmofKabiven®) to assess compatibility (i.e. potential precipitates and emulsion stability). The obtained compatibility data was interpreted according to theory and compared to existing compatibility literature to further check the validity of the methods.

Results

Light obscuration together with turbidimetry, visual inspection and pH-measurements were able to capture signs of precipitations. For the analysis of emulsion stability, light obscuration and estimation of percent droplets above 5 μm (PFAT5) seemed to be the most sensitive method; however laser diffraction and monitoring changes in pH might be a useful support. Samples should always be compared to unmixed controls to reveal changes induced by the mixing. General acceptance criteria are difficult to define, although some limits are suggested based on current experience. The experimental compatibility data was supported by scattered reports in literature, further confirming the suitability of the test program. However, conflicting data are common, which complicates the comparison to existing literature.

Conclusions

Testing of these complex blends should be based on a combination of several methods and accompanied by theoretical considerations.

Three-in-one parenteral nutrition in neonates and pediatric patients: risks and benefits

Parenteral nutrition (PN) is a life-sustaining therapy designed to deliver essential nutrients to patients unable to meet nutrition needs via the enteral route. PN may be delivered via a 2-in-1 system (one solution containing amino acids, dextrose, electrolytes, vitamins, minerals, and fluids and one solution containing intravenous fat emulsions [IVFEs]) or via a 3-in-1 system (all nutrients mixed in one container). Although the use of 3-in-1 PN solutions is not necessarily therapeutically advantageous, certain benefits may exist such as the potential to reduce the risk of contamination due to decreased manipulations; ease of administration, particularly in the home care setting; possible cost savings; and reduced IVFE wastage. However, the incorporation of IVFE in 3-in-1 solutions also presents unique risks for the neonatal and pediatric population such as decreased stability, increased lipid globule size, decreased sterility and the potential for increased microbial growth/infectious complications, the need to use a larger filter size, precipitation and compatibility risks, and an increased chance of catheter occlusion. This review outlines the unique issues and challenges to be considered when formulating neonatal and pediatric 3-in-1 PN admixtures. While 3-in-1 PN solutions may be advantageous for certain pediatric populations, specifically those dependent on home PN, the risks do not outweigh the benefits in neonatal patients, and use should be avoided in this population.

A.S.P.E.N. clinical guidelines: parenteral nutrition ordering, order review, compounding, labeling, and dispensing

BACKGROUND

Parenteral nutrition (PN) is a high-alert medication available for patient care within a complex clinical process. Beyond application of best practice recommendations to guide safe use and optimize clinical outcome, several issues are better addressed through evidence-based policies, procedures, and practices. This document provides evidence-based guidance for clinical practices involving PN prescribing, order review, and preparation.

METHOD

A systematic review of the best available evidence was used by an expert work group to answer a series of questions about PN prescribing, order review, compounding, labeling, and dispensing. Concepts from the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) format were applied as appropriate. The specific clinical guideline recommendations were developed using consensus prior to review and approval by the American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) Board of Directors. The following questions were addressed: (1) Does education of prescribers improve PN ordering? (2) What is the maximum safe osmolarity of PN admixtures intended for peripheral vein administration? (3) What are the appropriate calcium intake and calcium-phosphate ratios in PN for optimal neonatal bone mineralization? (4) What are the clinical advantages or disadvantages of commercially available premade ("premixed") multichambered PN formulations compared with traditional/customized PN formulations? (5) What are the clinical (infection, catheter occlusion) advantages or disadvantages of 2-in-1 compared with 3-in-1 PN admixtures? (6) What macronutrient dosing limits are expected to provide for the most stable 3-in-1 admixtures? (7) What are the most appropriate recommendations for optimizing calcium (gluconate) and (Na- or K-) phosphate compatibility in PN admixtures? (8) What micronutrient contamination is present in parenteral stock solutions currently used to compound PN admixtures? (9) Is it safe to use the PN admixture as a vehicle for non-nutrient medication delivery? (10) Should heparin be included in the PN admixture to reduce the risk of central vein thrombosis? (11) What methods of repackaging intravenous fat emulsion (IVFE) into smaller patient-specific volumes are safe? (12) What beyond-use date should be used for (a) IVFE dispensed for separate infusion in the original container and (b) repackaged IVFE?

Compatibility of intravenous medications with parenteral nutrition: in vitro evaluation

BACKGROUND AND AIM

Hospitalized patients requiring parenteral nutrition (PN) often need to receive intravenous (IV) medications as well. Y-site administration is occasionally necessary, but physicochemical incompatibilities can occur between the medications and PN. The aim of the present study was to assess the physical compatibility between 25 frequently coadministered IV medications and a commercially available ready-to-use total PN.

METHODS

PN (NuTRIflex Lipid Special; B. Braun Medical AG, Sempach, Switzerland) and medications were mixed in 1:1 (v/v) proportions, and the stability was assessed at the time of mixing and after 1 and 4 hours. The stability of lipid emulsion was observed by microscopic investigation, visual inspection, dynamic laser light scattering, and laser light obscuration. The binary admixtures of PN (without lipid emulsion) and medications were used to detect discoloration, visibly detectable precipitates, and subvisual particles.

RESULTS

Two of 25 medications were incompatible with the lipid emulsion (serum albumin 20% and tropisetron), 2 showed signs of degradation (discoloration) over time (esomeprazole and pantoprazole), and 1 precipitated at high concentrations (5-fluorouracil). The other 20 medications were considered compatible when administered by Y-site.

CONCLUSION

The present study validated the compatibility of 1 commercially available PN and 20 medications. These results offer new solutions to support the implementation of complex therapeutic schemes in practice, when coadministration via Y-site cannot be avoided.

Kinetic stability of all-in-one parenteral nutrition admixtures in the presence of high dose Ca2+ additive under clinical application circumstances

Background

TPN infusions are usually administered during a treatment period of 10–24 hours per day due to the metabolic capacity of the liver. During this time interval physicochemically stable TPN solution (emulsion) is needed for the treatment. The purpose of the present study was to examine how the kinetic stability features of ready-made total parenteral nutrition admixtures containing olive oil and soybean oil will change under the usage-modeling 24-hour application with and without overdose Ca²⁺.

Methods

Particle size analysis and zeta potential measurements were carried out to evaluate the possible changes in the kinetic stability of the emulsions.

Results

Our results indicate that in two of the four mixtures bimodal droplet-size distribution figures were detected and appearance of fat particles over 5 μm can not be disclosed. The tendency for separation of large diameter droplets in the two types of oil-based emulsion systems was different. In case of soybean containing emulsion second peak of droplets appeared in the bottom of the container in contrast to the olive oil containing emulsions where the second peak appeared in the surface layer. Interestingly this phenomenon is independent of calcium-content.

Conclusions

From therapeutic point the emulsions of the bigger droplets containing upper layer are safer because the potentially dangerous big droplets could remain in the infusion bag after the administration.