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Determination of the Porosity of PLGA Microparticles by Tracking Their Sedimentation Velocity Using a Flow Imaging
A S Sediq1, S K D Waasdorp1, M R Nejadnik1
1Division of Drug Delivery Technology, Cluster BioTherapeutics, Leiden Academic Centre for Drug Research (LACDR), Leiden University, Leiden, The Netherlands.
Pharmaceutical Research
|February 19, 2017
Summary
Particle porosity can be determined using flow imaging microscopy and sedimentation velocity tracking. This method accurately measures microparticle porosity with minimal sample amounts, offering a viable alternative to traditional techniques.
Area of Science:
- Materials Science
- Chemical Engineering
- Biotechnology
Background:
- Microparticle characterization is crucial for various applications.
- Accurate determination of microparticle porosity is essential for understanding material properties and performance.
- Existing methods for porosity measurement can be resource-intensive.
Purpose of the Study:
- To investigate the utility of flow imaging microscopy (FlowCAM) coupled with sedimentation velocity tracking for determining microparticle porosity.
- To develop and validate novel methods for microparticle porosity assessment.
Main Methods:
- Two methods were developed: 1) tracking sedimentation rates in varying density media to extrapolate to zero velocity, and 2) using Stokes' law with particle size and velocity in a single medium.
- Polystyrene beads were used for method development and validation.
- Methods were applied to poly(lactic-co-glycolic acid) (PLGA) microparticle batches.
Main Results:
- Both developed methods yielded porosity values in excellent agreement with expected values.
- Porosity measurements for PLGA microparticles (4-52%) were consistent between the two methods.
- Results showed strong correlation with mercury intrusion porosimetry, a standard technique.
Conclusions:
- Two novel methods for determining average microparticle density and porosity via sedimentation velocity tracking were successfully developed.
- These methods require only small sample quantities (milligrams).
- Sedimentation velocity tracking offers a sensitive and efficient approach for microparticle porosity determination.
