Related Experiment Video
Updated: Jun 21, 2026
13:17
Manufacture of Concentrated, Lipid-based Oxygen Microbubble Emulsions by High Shear Homogenization and Serial Concentration
Published on: May 26, 2014
Changes in lipid-encapsulated microbubble population during continuous infusion and methods to maintain consistency.
Mehmet Kaya1, Thomas S Gregory, Paul A Dayton
1Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, NC 27599, USA.
Ultrasound in Medicine & Biology
|July 28, 2009
Summary
Microbubbles, used as ultrasound contrast agents, change concentration and size in syringes over time due to flotation. This impacts consistent dosing for quantitative imaging and continuous infusion applications.
Area of Science:
- Biomedical Engineering
- Ultrasound Imaging
- Materials Science
Background:
- Stabilized microbubbles are crucial ultrasound contrast agents for enhanced imaging.
- Continuous infusion strategies require consistent microbubble delivery for quantitative analysis.
- Microbubble buoyancy causes stratification in syringes, altering injected agent properties.
Purpose of the Study:
- To investigate the impact of microbubble flotation on contrast agent distribution within syringes.
- To quantify changes in microbubble concentration and mean diameter over time.
- To identify factors influencing microbubble stratification and explore mitigation strategies.
Main Methods:
- Studied microbubble populations pumped from syringes over time.
- Varied suspension medium and syringe diameter to assess effects on flotation.
- Analyzed changes in microbubble concentration and mean diameter.
Main Results:
- Microbubble distribution in syringes changes significantly over several minutes without mixing.
- Both concentration and mean diameter of the injected agent varied due to flotation.
- Suspension medium and syringe diameter influenced the rate of change.
Conclusions:
- Microbubble flotation leads to inconsistent contrast agent delivery from syringes.
- Researchers must consider microbubble stratification in continuous-infusion ultrasound applications.
- Mixing systems or viscosity modifiers can improve contrast agent homogeneity and delivery consistency.
Related Concept Videos
01:24Drug Accumulation During Multiple Dosing: Intermittent IV Infusions
Intermittent intravenous (IV) infusion is a method of drug administration where medications are delivered over short infusion periods followed by intervals of no drug delivery. This approach helps to prevent sustained high drug concentrations in the bloodstream, reducing the risk of adverse effects associated with prolonged exposure. Unlike continuous infusion, steady-state concentrations may not be achieved during a single dosing cycle but can be reached through repeated...
01:25Determination of Multiple Dosing Parameters: Loading and Maintenance Doses
A loading dose is an essential pharmacological strategy to rapidly achieve the target plasma drug concentration necessary for an immediate therapeutic effect. This approach is especially critical for drugs characterized by slow absorption or extended half-lives, where delaying therapeutic plasma levels could compromise treatment outcomes. By administering a loading dose, clinicians ensure a prompt onset of drug action, even for agents with complex pharmacokinetic profiles.Achieving steady-state...
01:05Steady State Concentration
A steady state refers to the level of a drug in the body once it has reached an equilibrium between administration and elimination. It represents the point at which the drug administration rate equals the drug elimination rate, resulting in a relatively constant concentration in the body over time. The dynamic equilibrium is crucial to ensure the drug's effectiveness with minimal risk of toxicity.
Most drugs are administered in repeated doses at fixed intervals or through continuous intravenous...
Most drugs are administered in repeated doses at fixed intervals or through continuous intravenous...
01:14Compartment Models: Single-Compartment Model
The single-compartment model serves as a simplified representation of the human body. This model assumes that the body functions as a single, well-mixed open compartment. When a drug is administered intravenously, it enters the body and quickly distributes uniformly. The drug then undergoes biotransformation and elimination, ultimately leaving the body. The volume of this compartment is referred to as the apparent volume of distribution into which the drug can uniformly distribute. In this...
01:15Determination of Multiple Dosing Parameters: Steady-State, Minimum and Maximum Concentrations
Gentamicin, an aminoglycoside antibiotic, is commonly administered via intermittent intravenous infusion to treat severe infections. An intermittent one-hour infusion of gentamicin, administered at eight-hour intervals, allows for precise control of plasma drug concentrations, minimizing toxicity while ensuring therapeutic efficacy. Pharmacokinetic principles govern the dynamics of plasma concentrations and can be mathematically described using specific equations.The plasma drug concentration...
01:09One-Compartment Model: IV Infusion
Intravenous (IV) infusion is often utilized when continuous and controlled drug delivery is necessary, such as during surgery or in the treatment of chronic diseases. This method offers numerous advantages, including immediate drug action, precise control over dosage, and bypassing the first-pass metabolism.
The one-compartment model for IV infusion uses mathematical equations to describe the rate of change in drug quantity in the body. At steady-state or infusion equilibrium, the drug input...
The one-compartment model for IV infusion uses mathematical equations to describe the rate of change in drug quantity in the body. At steady-state or infusion equilibrium, the drug input...