Tunable sustained release drug delivery system based on mononuclear aqueous core-polymer shell microcapsules

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Pharmaceutical Sciences

Background:

• Polymeric microcapsules are crucial for controlled drug delivery.
• Poly(d,l-lactide-co-glycolide) (PLGA) and poly(d,l-lactide) (PLA) are biocompatible polymers widely used in drug delivery.
• Developing microcapsules with aqueous cores is essential for encapsulating hydrophilic drugs.

Purpose of the Study:

• To prepare and characterize polymer shell microcapsules with mononuclear aqueous cores using PLGA and PLA.
• To evaluate the drug loading, encapsulation efficiency, and drug release kinetics of these microcapsules.
• To investigate the potential of tuning drug release rates by altering polymer composition.

Main Methods:

• Internal phase separation method was employed for microcapsule preparation.
• Varying ratios of PLGA, PLA, and water were used to optimize microcapsule formulation.
• Fluorescein sodium was used as a model water-soluble drug for loading and release studies.
• Drug release kinetics were analyzed to determine release mechanisms.

Main Results:

• An optimal polymer to water ratio of approximately 1:3 was identified for efficient drug loading.
• PLGA microcapsules demonstrated sustained drug release over 7 days, while PLA microcapsules released drugs over 49 days.
• Drug release from both types of microcapsules followed zero-order kinetics for the initial 90% of release.
• Blending PLGA and PLA polymers allowed for further modulation of drug release rates.

Conclusions:

• Aqueous core-PLGA and PLA microcapsules are effective platforms for sustained delivery of hydrophilic drugs.
• The drug release rate can be precisely controlled by adjusting the ratio of PLGA to PLA polymers.
• These microcapsules hold significant promise for developing advanced and versatile drug delivery systems.