Formulation and characterization of catalase in albumin microspheres

Abstract

Catalase in albumin microspheres were formulated for intravenous administration to antagonize the effects of over-production of reactive oxygenated species (ROS) such as hydrogen peroxide (H₂O₂) in septic shock. The aim was to increase effective half-life of catalase and take advantage of the phagocytic uptake of the encapsulated catalase by the vascular endothelium. Catalase microspheres were prepared by spray-drying. The microspheres were evaluated for particle size, particle shape and surface morphology by scanning electron microscopy (SEM), drug encapsulation efficiency, chemical stability, thermal stability and in vitro drug release characteristics. The microspheres had a mean particle size of 4.7 ± 2 µm, optimal for phagocytic uptake, as demonstrated by Makino et al. SEM revealed that microspheres were spherical with smooth surface morphology. An encapsulation efficiency of 91.5 ± 3% was achieved and the encapsulated catalase was chemically and thermally stable. Application of in vitro drug release data to the Higuchi kinetic equation indicated matrix diffusion-controlled catalase release from albumin microspheres.

Key words::

• Microspheres
• albumin
• catalase

Acknowledgements

This study was supported by Dr Carl. W. Oettinger from the Dialysis Clinics of Atlanta and performed under the direction of Dr Martin J. D'Souza at the College of Pharmacy and Health Sciences, Mercer University, Atlanta, GA.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.