NSAIDs bound to methacrylic carriers: microstructural characterization and in vitro release analysis

Area of Science:

• Polymer Chemistry
• Materials Science
• Drug Delivery Systems

Background:

• Chemically controlled drug delivery systems, or 'polymeric drugs', are synthesized using copolymers.
• These systems incorporate active pharmaceutical ingredients like ibuprofen or ketoprofen directly into the polymer structure via labile ester bonds.

Purpose of the Study:

• To prepare and characterize novel polymeric drugs based on 2-hydroxyethyl methacrylate (HEMA) and methacrylic derivatives containing ibuprofen or ketoprofen.
• To investigate the in vitro release kinetics of these drugs from the polymeric matrices under varying conditions.

Main Methods:

• Free radical polymerization in solution at 50°C to synthesize copolymers.
• Incorporation of three distinct spacer types (aromatic amide, aliphatic ester, combined) into the monomer structure.
• In vitro drug release studies at pH 7.4 and 9 with varying copolymer compositions (1-30 wt% active monomer).

Main Results:

• Microstructural analysis indicated a random distribution of monomer units in the copolymers.
• HEMA-rich copolymers showed isolated active drug residues, facilitating controlled release.
• Controlled drug release over several weeks was observed, influenced by spacer type, drug identity (ketoprofen faster than ibuprofen), copolymer composition, and pH.

Conclusions:

• The developed polymeric drugs demonstrate tunable, long-term drug release capabilities.
• Release profiles are significantly modulated by the chemical structure of the copolymer and environmental pH.
• These findings highlight the potential of these polymeric drugs for advanced therapeutic applications.