Preparation and characterization of heparin-loaded polymeric microparticles

Area of Science:

• Materials Science
• Polymer Chemistry
• Pharmaceutical Technology

Background:

• Heparin delivery systems are crucial for various therapeutic applications.
• Developing microparticle formulations requires careful selection of polymers and excipients to control drug release.
• Biodegradable and non-biodegradable polymers offer distinct properties for drug encapsulation.

Purpose of the Study:

• To investigate the preparation of heparin-loaded microparticles using biodegradable and non-biodegradable polymers.
• To evaluate the impact of different polymers (PCL, PLGA, Eudragit RS/RL) and excipients (gelatin, NaCl) on microparticle characteristics.
• To assess the in vitro release kinetics and biological activity of encapsulated heparin.

Main Methods:

• Water-in-oil-in-water emulsification and evaporation technique for microparticle preparation.
• Analysis of particle size, morphology, and drug entrapment efficiency.
• In vitro drug release studies and anti-Xa activity assay to confirm heparin's biological integrity.

Main Results:

• Microparticle diameters ranged from 80-130 microns, influenced by gelatin A addition.
• Eudragit RS/RL microparticles showed higher entrapment but lower 24-hour release compared to PCL/PLGA.
• Polymer blends modified entrapment and release kinetics; gelatin A increased entrapment but caused an initial burst release.
• Released heparin retained its anti-Xa biological activity, confirming no degradation during formulation.

Conclusions:

• Heparin microparticles can be successfully prepared using various biodegradable and non-biodegradable polymers.
• Polymer choice and excipients significantly modulate microparticle properties and drug release profiles.
• Formulated heparin maintains its therapeutic efficacy, indicating a promising approach for controlled heparin delivery.