Preparation and characterisation of polyphosphazene-based controlled release systems for naproxen

Area of Science:

• Polymer Chemistry
• Materials Science
• Pharmacology

Background:

• Development of advanced drug delivery systems is crucial for effective therapeutic outcomes.
• Polyphosphazenes offer versatile platforms for biomedical applications due to their tunable properties.

Purpose of the Study:

• To synthesize and characterize a new polyphosphazene polymer for naproxen controlled release.
• To evaluate the in vitro and in vivo performance of naproxen-loaded polyphosphazene matrices.
• To investigate the influence of drug concentration and matrix properties on drug release kinetics.

Main Methods:

• Non-complete substitution of polydichlorophosphazene with phenylalanine ethyl ester and imidazole.
• Preparation of polymeric disks via solvent evaporation.
• In vitro and in vivo drug release studies.
• Scanning electron microscopy (SEM) for surface analysis.
• Pharmacological evaluation in acute and chronic inflammation models.

Main Results:

• The polyphosphazene polymer maintained disk integrity for extended periods in vitro and in vivo.
• Naproxen release rate was dependent on matrix thickness and drug loading.
• High drug concentrations resulted in initial release spikes, while lower concentrations approximated zero-order kinetics.
• SEM revealed naproxen crystals on the surface of matrices exhibiting release spikes.
• In vivo studies demonstrated the utility of initial spikes for acute inflammation and sustained release for chronic inflammation.

Conclusions:

• A novel polyphosphazene polymer is suitable for developing naproxen controlled release systems.
• The polymer matrices provide tunable drug release profiles, adaptable for different inflammatory conditions.
• Preliminary data suggest potential for effective management of both acute and chronic inflammatory diseases.