Surface drug removal from ibuprofen-loaded PLA microspheres

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Pharmaceutical Sciences

Background:

• Poly(D,L-lactic acid) (PLA) microspheres are widely used for controlled drug delivery.
• Ibuprofen is a common non-steroidal anti-inflammatory drug (NSAID).
• Optimizing drug loading and release kinetics is crucial for effective therapeutic outcomes.

Purpose of the Study:

• To prepare and characterize ibuprofen-loaded PLA microspheres.
• To investigate the effect of surface drug removal on microsphere properties and drug release.
• To analyze the drug release behavior of treated and untreated microspheres.

Main Methods:

• Preparation of PLA microspheres using a double emulsion solvent evaporation method.
• Varying gelatin concentration to control microsphere size.
• Washing microspheres with water (Untreated Microspheres, Un-Ms) or sodium carbonate solution (Treated Microspheres, T-Ms) to remove surface drug.
• Characterization of microsphere size, morphology, and drug release profiles.

Main Results:

• Microsphere size (2.2, 4.1, 7.5 µm) was controlled by gelatin concentration.
• Surface drug removal did not alter microsphere size but modified the morphology of smaller T-Ms.
• Both Un-Ms and T-Ms exhibited biphasic drug release patterns.
• T-Ms showed a lower initial burst effect compared to Un-Ms.
• The second release phase rate increased for smaller microspheres, potentially due to altered matrix porosity.

Conclusions:

• Surface drug removal is a viable method to modulate initial drug release from PLA microspheres.
• Altering microsphere porosity through surface treatment can influence sustained drug release rates.
• PLA microspheres offer tunable properties for controlled delivery of drugs like ibuprofen.