Aspirin-Loaded Polymeric Films for Drug Delivery Systems: Comparison between Soaking and Supercritical CO₂...

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Polymer Chemistry

Background:

• Polymeric implants offer advantages over traditional drug administration for localized therapy.
• Various methods exist for loading drugs into polymers, each with distinct efficiencies.
• Understanding drug loading and release kinetics is crucial for effective implant design.

Purpose of the Study:

• To compare the efficacy of supercritical CO2 (scCO2) impregnation versus soaking for loading aspirin into poly(l-lactic acid) (PLLA) and linear low-density polyethylene (LLDPE).
• To evaluate the impact of different loading methods on drug loading, residual solvents, polymer properties, and in vitro drug release profiles.
• To determine the optimal method for achieving high drug loading and controlled release from polymeric implants.

Main Methods:

• Aspirin was loaded into PLLA and LLDPE using both soaking and scCO2 impregnation.
• Drug loading (DL) was quantified for each method and polymer.
• In vitro hydrolysis and drug release studies were conducted.
• Residual solvents and polymer crystallinity were analyzed.

Main Results:

• scCO2 impregnation resulted in significantly higher aspirin DL and shorter loading times compared to soaking.
• PLLA demonstrated higher DL than LLDPE due to greater aspirin affinity.
• Solvents acted as plasticizers, increasing PLLA crystallinity.
• Aspirin-loaded PLLA showed accelerated in vitro hydrolysis.
• Soaking-prepared PLLA exhibited a burst release, while scCO2-prepared PLLA demonstrated sustained release over 74 days.

Conclusions:

• scCO2 impregnation is a superior method for achieving higher aspirin loadings in PLLA and LLDPE.
• The scCO2 method facilitates prolonged drug release, making it suitable for advanced localized drug delivery.
• Polymer properties and drug release kinetics are significantly influenced by the loading technique.