Jet milling--a new technique for microparticle preparation

Area of Science:

• Pharmaceutical Technology
• Materials Science

Background:

• Traditional microparticle preparation often involves organic solvents, posing environmental and safety concerns.
• Developing solvent-free methods is crucial for sustainable pharmaceutical manufacturing.

Purpose of the Study:

• To describe and validate an innovative melt grinding technique for solvent-free microparticle preparation.
• To investigate the influence of process parameters on microparticle characteristics.
• To evaluate the drug release profile of prepared microparticles.

Main Methods:

• Microparticles were prepared using a three-step melt grinding process: melting/co-melting, pregrinding, and jet milling.
• Polylactic acid (PLA) and poly(lactic-co-glycolic acid) (PLGA) polymers were utilized.
• A 2((5-2)) factorial design was employed to study preparation parameters and microparticle properties (particle size, habitus, surface morphology).
• Scanning electron microscopy (SEM) was used for surface morphology analysis.
• In vitro drug release studies were performed using estrioltriacetate loaded microparticles.

Main Results:

• The melt grinding technique successfully produced microparticles with a mean particle size (x50) of 4-6 micrometers.
• SEM confirmed the preparation of non-porous microparticles with smooth surfaces.
• Drug-loaded microparticles exhibited a near zero-order release kinetic over 21 days, with no initial burst effect.
• The preparation process demonstrated reproducibility.

Conclusions:

• The described melt grinding technique is an effective and reproducible method for solvent-free microparticle preparation.
• This technique yields microparticles with desirable properties, including controlled drug release.
• It presents a viable, environmentally friendly alternative to conventional solvent-based methods in pharmaceutical manufacturing.