Poly-lactide-co-glycolide microparticle sizes: a rational factorial design and surface response analysis

Area of Science:

• Materials Science
• Pharmaceutical Sciences
• Chemical Engineering

Background:

• Microsphere size critically influences drug release rates.
• Controlling microsphere size is essential for predictable drug delivery.
• Poly(lactic-co-glycolic acid) (PLGA) microspheres are widely used in drug delivery systems.

Purpose of the Study:

• To establish a controllable method for producing poly(lactic-co-glycolic acid) (PLGA) microspheres of varying sizes.
• To investigate the impact of key process variables on PLGA microsphere size.
• To optimize PLGA microsphere formulation for specific size requirements.

Main Methods:

• Utilized a full factorial experimental design (2^3) with central points to study process variables.
• Investigated stirring velocity, phase volume ratio, and poly(vinyl alcohol) concentration.
• Analyzed surface response to understand variable interactions and their effect on microsphere size.

Main Results:

• Stirring velocity and poly(vinyl alcohol) concentration significantly influenced PLGA microsphere size (p < 0.05).
• Higher poly(vinyl alcohol) concentration and stirring velocity yielded smaller microspheres.
• Lower poly(vinyl alcohol) concentration and stirring velocity resulted in larger microspheres.
• Microsphere size was controllable within the 4-15 micrometer range with uniform spherical morphology.
• No significant impact on Ponca S loading was observed within the studied experimental region.

Conclusions:

• A rational approach to producing size-controlled PLGA microspheres was successfully demonstrated.
• The findings enable the formulation of PLGA microspheres with custom sizes for targeted applications.
• This method minimizes experimental effort for achieving desired microsphere characteristics.