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.

Use of Total Parenteral Nutrition (TPN) as a Vehicle for Drug Delivery

Total Parenteral Nutrition (TPN) is a method of providing nutrients directly into the bloodstream for individuals who are unable to meet their nutritional needs through the normal digestive process or gastrointestinal system. It provides macronutrients and micronutrients in a single container, reducing handling and contamination risks and making it more cost-effective. TPN has the potential to be used as a drug delivery system, with applications in combination therapies, personalized medicine, and integrating advanced technologies. It can enhance drug dosage precision and provide nutritional assistance, potentially reducing hospitalization and improving patient outcomes. However, implementing new applications requires thorough testing and regulatory approval. TPN could be particularly useful in pediatric and geriatric care and could also contribute to global health by combating malnutrition in areas with limited medical resources. Healthcare professionals prepare a sterile solution tailored to each patient's nutritional needs, and administration involves a central venous catheter. However, the simultaneous administration of medications with PN admixtures can result in pharmacological incompatibility, which can impact the stability of the oil-in-water system. The European Society for Clinical Nutrition and Metabolism and the American Society for Parenteral and Enteral Nutrition recommendations advise against including non-nutrient drugs in PN admixtures due to safety concerns. This review focuses on the utilization of Total Parenteral Nutrition (TPN) as a method for delivering drugs. It discusses the benefits and difficulties associated with its commercial application and offers suggestions for future research endeavors.

Stability and compatibility of parenteral nutrition solutions; a review of influencing factors

Both stability and compatibility of parenteral nutrition solutions (PNS) with drug products are major concerns for clinicians and clinical pharmacists, especially when concurrent administration of PNS with intravenous medications (IVM) is unavoidable. Since the same physicochemical principles apply to both adult's and paediatrics' PNS, concerns about stability and compatibility may still apply to both. However, these concerns are relatively more common in paediatrics and neonatal clinical settings, where limited vascular access can be problematic and the coadministration of PNS and drugs is more common. In neonatal and paediatric populations, there have been few experimental studies and comprehensive evaluations looking at medication compatibility with frequently used PNS. This work is part of a larger research project concerned for compatibility of PNS with commonly used intravenous medication in paediatric and neonates. This paper captures and reviews published data on factors influencing stability and compatibility of parenteral nutrition solutions. This information will help clinicians and clinical pharmacists to understand the principals of the stability and compatibility of PNS, furthermore, it will inform better design of future compatibility studies, as it highlights the complexity of PNS and the multiple factors influencing the stability of PNS, and hence its compatibility with IVM. When preparing, prescribing, and administering the PNS, especially when co-administration with IVM is unavoidable, it is important to take into account the physicochemical properties of the PNS components and IVM as well as administration conditions and environmental factors. These factors should also be considered in the design of the compatibility studies of the PNS with the IVM.

Physical Stability of Medium-Chain Triglyceride/Long-Chain Triglyceride Emulsion Injections From 5 Manufacturers in High-Concentration Electrolyte-Based Total Nutrient Admixtures

BACKGROUND

Lipid emulsion injections for parenteral nutrition are an important source of energy and essential fatty acids. Yet stability and compounding challenges remain. We compared the physicochemical stability of 5 commercial medium-chain triglyceride/long-chain triglyceride (MCT/LCT)-based lipid emulsions compounded in total nutrient admixtures (TNAs).

METHODS

Stability of the MCT/LCT-based TNAs was assessed when compounded with high concentrations of electrolytes. We measured mean droplet diameter (MDD), percentage of fat residing in globules ≥5 μm (PFAT5), pH, and osmolality immediately after compounding (time 0) and 6, 12, 18, 24, 36, 48, 60, and 72 hours later. Repeated-measures analyses of variance were used to evaluate changes in stability over time, and post hoc tests were used to assess group differences.

RESULTS

Over 72 hours, MDD of TNAs ranged from 0.206 to 0.713 μm, PFAT5 from 0.58% × 10^-3 to 43.18% × 10^-3 , pH from 5.769 to 5.879, and osmolality from 1304 to 1357 mOsm/kg. MDDs and PFAT5s showed a tendency to increase gradually over the first 24 hours and then decrease or remained stable after that. We identified some significant differences in MDDs and PFAT5s among the 5 MCT/LCT-based TNAs, although all met the United States Pharmacopeia <729> standards.

CONCLUSIONS

The stability of some commercial MCT/LCT-based TNAs under high concentrations of electrolytes exhibits differences over the 72 hours after compounding. Clinicians should pay attention, therefore, to possible performance differences of injectable lipid emulsions produced by different manufacturers when compounded in TNAs under high electrolyte concentrations.

Stability Study and Clinical Evaluation of Lipid Injectable Emulsion in Parenteral Nutrition Admixtures Used for Preterm Neonates

BACKGROUND

Intravenous administration of parenteral nutrition (PN) admixtures containing 4-oil lipid injectable emulsion (ILE) in preterm neonates is usually prohibited because of limited clinical data. The authors evaluated the stability, safety, and efficacy of PN admixtures containing 4-oil ILE, for the first time, in preterm neonates.

METHODS

A series of PN admixtures were prepared for consecutive administration in preterm neonates over a period of 15 days. Admixture stability was assessed after 24 hours of storage at 25 and 37 °C via visual inspection and measurement of mean droplet size (MDS). Safety and efficacy of the admixtures in preterm neonates were assessed via serum triglyceride levels and body weight increase measurements, respectively.

RESULTS

PN admixtures were stable at 25 °C and had MDS ˂500 nm. After 15 days, there was a significant increase in body weight (P ≤ .0001) and level of serum triglycerides (P ≤ .0001), compared with the level before PN administration.

CONCLUSIONS

PN admixtures containing 4-oil ILE were stable at 25 °C and showed instability at 37 °C. Therefore, it is recommended to keep the temperature during administration of PN admixtures at 25 °C. PN admixtures were well tolerated and safe over a period of 8 days while providing a balanced fatty acid supply. Tight monitoring of serum triglyceride level is essential, particularly in neonates of low birth weight and/or young gestational age, to avoid hypertriglyceridemia. Hence, the use of these PN admixtures is expected to be beneficial in terms of being cost-effective and reducing the contamination risks.

Compatibility of intravenous ibuprofen with lipids and parenteral nutrition, for use as a continuous infusion

There is increasing interest to administer ibuprofen as a continuous infusion instead of a traditional bolus for treating Patent Ductus Arteriosus (PDA). However, its compatibility data with commonly used drugs in the neonatal period, including parenteral nutrition (PN) and lipids is unavailable. The aim is to determine the compatibility of intravenous ibuprofen lysine with various ANZNN parenteral nutrition consensus group standard neonatal PN formulations and lipids. The PN and lipid solutions used in a tertiary neonatal unit were obtained. These included a Starter, Standard Preterm and low carbohydrate PN, and IV SMOF lipid admixture (SMOFLipid 20% 15 mL; Vitalipid N infant 4 mL, Soluvit N 1 mL) plus vitamin mixtures. 10% glucose was used as a control. 1:1 mixtures of different concentrations (1.25 to 5mg/mL) of ibuprofen lysine and each of the PN/glucose/lipid formulations were made. Samples were taken at hourly intervals for a total of 4 hours and tested for both physical (visual assessment, pH and microscopy) and chemical compatibility (High Performance Liquid Chromatography analysis). Zeta potential and particle diameter were measured for SMOF lipid admixture and ibuprofen combination to assess emulsion stability. 24 hour stability of ibuprofen dilution in 5 mL BD Luer-lok polypropylene syringes at 25°C was also assessed. Most PN formed opaque solutions when mixed with ibuprofen 2.5 and 5mg/mL solutions. However, ibuprofen dilution of 1.25mg/mL produced clear, colourless solutions with no microscopic particles when mixed with all PN/glucose/lipid formulations tested. Ibuprofen was chemically stable with all PN and SMOF lipid admixture, for a period of 4 hours. The zeta potential and particle diameter were within acceptable limits. Ibuprofen lysine was stable over 24 hours in Luer-lok polypropylene syringes. Ibuprofen 1.25mg/mL is physically and chemically compatible with 10% glucose, starter PN, standard preterm and low carbohydrate PN, and SMOF lipid admixture plus vitamins for a period of four hours, which is the maximum time they could be in an admixture during a continuous infusion.

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.

Assessment of the physicochemical stability of all-in-one parenteral emulsions for neonates according to USP specifications

BACKGROUND

The purpose of this study was to describe the methodology to assess the stability of all-in-one (AIO) parenteral nutrition admixtures, containing glucose, proteins, and lipids, to the standards of U.S. Pharmacopoeia (USP <729>). The influence of calcium and commercially available lipid emulsions and amino acid solutions were also examined.

METHODS

Four batches of 5 AIO admixtures containing calcium were compounded with commercially available lipid emulsions and amino acid solutions. Two of them contained calcium. Their stability was tested under conditions simulating clinical use. All the admixtures were assessed for criteria set by the USP <729>: (1) mean droplet diameter (MDD) and (2) percentage of volume weighted particles with diameter > 5 μm (PFAT5).

RESULTS

All admixtures were within the specifications set by the USP with respect to the MDD at 0, 24, and 48 hours, but only those batches lacking calcium met the benchmarks set by the pharmacopoeia, with respect to PFAT5, on the day of preparation.

CONCLUSIONS

The presence of calcium destabilized the admixtures, while the use of different commercial ingredients altered the admixtures' characteristics. Only 1 batch of the AIO admixtures studied was found to be compliant with USP <729> standards.

Influence of the relative composition of trace elements and vitamins in physicochemical stability of total parenteral nutrition formulations for neonatal use

OBJECTIVE

The present study aimed to evaluate the influence of the relative composition of trace elements and vitamins in physicochemical stability of neonatal parenteral nutrition.

MATERIAL AND METHODS

Three formulations for neonatal administration were selected; the main variable was the presence of trace elements and vitamins. The analyses where carried out immediately after preparation and at 24 h, 48 h, 72 h and 7 days after preparation. Three methods were selected to determine globule size: light obscuration, dynamic light scattering and optical microscopy. Complementary evaluation including visual inspection, determination of pH and osmolarity, peroxide levels and measurements of zeta potential were also performed.

RESULTS

There was an observable alteration in color and phase separation in the PN stored at 25°C and 40°C. Neither globule size pattern, nor any other physicochemical characteristic evaluated appeared to be considerably altered in any of the analyzed formulations even after 7 days of storage at 5°C. Globule size in all the PN studied was consistent with the established limit, below 500 nm by DLS measurement, and PFAT5 was below 0.05% under all storage temperatures.

CONCLUSION

Concomitant presence of trace elements and vitamins in the same neonatal formulation did not alter the evaluated aspects of stability.