Manufacturing monodisperse chitosan microparticles containing ampicillin using a microchannel chip

Area of Science:

• Biomaterials Science
• Microfluidics Engineering
• Pharmaceutical Technology

Background:

• Chitosan microparticles are promising drug delivery vehicles.
• Controlling microparticle size and drug release is crucial for efficacy.
• Existing methods for microparticle fabrication can be inefficient or lack precise control.

Purpose of the Study:

• To develop a microfluidic chip for producing size-controlled, monodisperse chitosan microparticles encapsulating ampicillin.
• To demonstrate the chip's capability in fabricating uniform microparticles efficiently.
• To investigate the drug release profile and its correlation with particle size.

Main Methods:

• Fabrication of a microfluidic chip using a CO2 laser on a poly methyl methacrylate (PMMA) substrate.
• Utilizing a cross-junction microchannel to shear a chitosan solution (disperse phase) with oil (continuous phase) forming chitosan emulsions.
• Gelation of emulsions using copper sulfate solution to form stable chitosan microparticles.
• Controlling microparticle size by adjusting the flow rate ratio between the disperse and continuous phases.

Main Results:

• Successfully prepared size-controlled monodisperse chitosan microparticles (100-800 microm, <5% variation).
• Demonstrated that microparticle size can be tuned by altering the sheath/sample flow rate ratio.
• Observed that emulsion size increases with the dispersed phase flow velocity.
• Confirmed once-daily release of ampicillin from the fabricated microspheres, suitable for clinical use.

Conclusions:

• The developed microfluidic chip provides an efficient method for producing uniform chitosan microparticles.
• Particle size control is achievable by manipulating flow rates within the microfluidic system.
• The predictable, once-daily drug release profile enhances the potential of these chitosan microparticles as drug carriers.