Related Experiment Video
Updated: Apr 7, 2026
11:14
Fatty Acid 13C Isotopologue Profiling Provides Insight into Trophic Carbon Transfer and Lipid Metabolism of Invertebrate Consumers
Published on: April 17, 2018
8.6K
PFAT5 and the Evolution of Lipid Admixture Stability
1Memorial Sloan Kettering Cancer Center, New York, New York klangm@mskcc.org.
JPEN. Journal of Parenteral and Enteral Nutrition
|July 17, 2015
Summary
The percentage of fat larger than 5 µm (PFAT5) is the only validated measure for lipid injectable emulsion stability. Previous methods like particle size are unreliable, and exceeding the PFAT5 limit has clinical consequences.
Area of Science:
- Parenteral nutrition
- Lipid emulsion stability
- Pharmacopeial standards
Background:
- Intravenous fat emulsions (IVFEs) are crucial in total nutrient admixtures (TNAs).
- Assessing IVFE stability in TNAs is critical for patient safety.
- Traditional methods for assessing lipid stability lack validation.
Purpose of the Study:
- To review traditional methods for assessing IVFE stability in TNAs.
- To highlight the limitations of current stability assessment parameters.
- To establish the percentage of fat larger than 5 µm (PFAT5) as the validated measure of lipid stability.
Main Methods:
- Review of existing literature on IVFE stability assessment.
- Analysis of traditional parameters: mean particle size, zeta potential, and visual checks.
- Emphasis on the United States Pharmacopeia Chapter 729 definition of PFAT5.
Main Results:
- Traditional methods (particle size, zeta potential, visual checks) are not valid measures of lipid stability.
- The PFAT5 parameter is the only validated method for assessing lipid stability.
- Exceeding the PFAT5 limit (0.05%) can lead to accumulation of unstable aggregates in organs.
Conclusions:
- Clinicians must be aware of the limitations in current literature regarding lipid stability assessment.
- PFAT5 is applicable to both manufactured and compounded lipid preparations.
- Further research using PFAT5 is needed to define the actual limits of TNA compounding.
Related Concept Videos
01:32Lipids as Anchors
8.0K
In the plasma membrane, the lipids forming the bilayer can also act as an anchor to tether proteins to the membrane. The three main types of lipid anchors found in eukaryotes are – prenyl groups, fatty acyl groups, and glycosylphosphatidylinositol or GPI groups. Prenyl and fatty acyl groups act as anchors on the cytosolic surface of the membrane, whereas GPI anchors proteins on the extracellular side.
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains...
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains...
8.0K
01:23Membrane Fluidity
179.5K
Cell membranes are composed of phospholipids, proteins, and carbohydrates loosely attached to one another through chemical interactions. Molecules are generally able to move about in the plane of the membrane, giving the membrane its flexible nature called fluidity. Two other features of the membrane contribute to membrane fluidity: the chemical structure of the phospholipids and the presence of cholesterol in the membrane.
179.5K
01:26Membrane Fluidity
18.0K
Membrane fluidity is explained by the fluid mosaic model of the cell membrane, which describes the plasma membrane structure as a mosaic of components—including phospholipids, cholesterol, proteins, and carbohydrates—that gives the membrane a fluid character.
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is...
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is...
18.0K
01:38What are Lipids?
225.4K
Overview
225.4K
01:29Biosynthesis of Lipids
882
Microbial membranes exhibit remarkable diversity in lipid composition, reflecting evolutionary adaptations to various environmental conditions. The three domains of life—Bacteria, Archaea, and Eukarya—synthesize membrane lipids through distinct biosynthetic pathways, leading to fundamental structural differences that impact membrane stability, function, and adaptability.Fatty Acid-Based Lipids in Bacteria and EukaryaBacteria and eukaryotes share a common fatty acid biosynthesis...
882
01:28Overview of Fatty Acid Metabolism
37.8K
Lipids also are sources of energy that power cellular processes. Like carbohydrates, lipids are composed of carbon, hydrogen, and oxygen, but these atoms are arranged differently. Most lipids are nonpolar and hydrophobic. Major types include fats and oils, waxes, phospholipids, and steroids.
Fatty acids are catabolized in a process called beta-oxidation, which takes place in the matrix of the mitochondria and converts their fatty acid chains into two-carbon units of acetyl groups. The acetyl...
Fatty acids are catabolized in a process called beta-oxidation, which takes place in the matrix of the mitochondria and converts their fatty acid chains into two-carbon units of acetyl groups. The acetyl...
37.8K