Fluconazole encapsulation in PLGA microspheres by spray-drying

Area of Science:

• Polymer science
• Materials science
• Pharmaceutical technology

Background:

• Polymeric microspheres are widely used for drug delivery.
• Controlling drug release from microspheres is crucial for therapeutic efficacy.
• Fluconazole is a common antifungal medication.

Purpose of the Study:

• To prepare fluconazole-loaded poly(lactic-co-glycolic acid) (PLGA) microspheres using spray-drying.
• To investigate the influence of process parameters, particularly drug loading, on microsphere characteristics and drug release.
• To understand the physical state of fluconazole within the PLGA matrix.

Main Methods:

• Spray-drying technique for microsphere preparation.
• Characterization of microsphere physical properties (e.g., size, size distribution).
• Differential thermal analysis (DTA) and X-ray powder diffraction (XRPD) to determine drug's physical state.
• In vitro drug release studies.

Main Results:

• Polymer type and concentration did not significantly affect microsphere diameter, size distribution, or encapsulation efficiency.
• Drug loading significantly influenced microsphere size and the physical state of fluconazole (amorphous/molecular dispersion vs. crystalline).
• Drug release exhibited a biphasic pattern, with release kinetics dependent on polymer nature, drug loading, and fluconazole's physical state.

Conclusions:

• Spray-drying is a viable method for producing fluconazole-loaded PLGA microspheres.
• Drug loading is a critical factor controlling microsphere properties and drug release behavior.
• The physical state of fluconazole within the PLGA matrix dictates its release profile, offering potential for controlled antifungal therapy.