Preparation, characterization and performance evaluation of neomycin-HSA microspheres

Area of Science:

• Biomaterials Science
• Pharmaceutics
• Drug Delivery Systems

Background:

• Human serum albumin (HSA) is a biocompatible polymer widely used in drug delivery.
• Microspheres offer controlled release and targeted delivery of therapeutic agents.
• Neomycin sulfate is an aminoglycoside antibiotic with a narrow therapeutic index.

Purpose of the Study:

• To prepare and characterize human serum albumin microspheres containing neomycin sulfate.
• To investigate the effect of various formulation parameters on microsphere properties.
• To evaluate the in vitro drug release and in vivo biodistribution of the microspheres.

Main Methods:

• Microspheres were prepared using emulsion polymerization and polymer dispersion techniques.
• Variables studied included phase ratios, HSA content, stirring rate, polymer content, and stabilizer concentration.
• In vitro drug release was assessed using a dialysis cell method.
• In vivo distribution studies were conducted to determine tissue localization.

Main Results:

• Polymer dispersion stabilized microspheres exhibited uniform size and narrow size distribution compared to emulsion polymerization.
• Drug release followed a Q versus (t)-1/2 linear relationship, indicating diffusion-controlled release.
• In vivo studies showed preferential localization in lung, liver, spleen, and kidney, dependent on microsphere size.
• Microspheres of 3-6 microns achieved approximately 55% localization in lung tissues.

Conclusions:

• Polymer dispersion is a superior technique for producing uniform HSA microspheres for neomycin sulfate.
• The size of HSA microspheres significantly influences their in vivo biodistribution, with a preference for lung accumulation.
• These findings support the potential of HSA microspheres for targeted lung delivery of neomycin sulfate.