Disodium norcantharidate loaded poly(epsilon-caprolactone) microspheres I. Preparation and evaluation

Area of Science:

• Materials Science
• Pharmaceutical Sciences
• Polymer Chemistry

Background:

• Disodium norcantharidate (DSNC) is a water-soluble drug.
• Poly(epsilon-caprolactone) (PCL) is a biodegradable polymer often used for drug delivery systems.

Purpose of the Study:

• To prepare and characterize PCL microspheres for encapsulating DSNC.
• To investigate the influence of process parameters and material properties on DSNC encapsulation and release.

Main Methods:

• Solvent-in-oil-in-water (s/o/w) emulsion solvent evaporation technique was employed.
• Microsphere characterization included size, morphology (SEM), encapsulation efficiency, and drug release studies.
• X-ray diffraction (XRD) was used to analyze drug-polymer interactions and crystallinity.

Main Results:

• Dispersion viscosity was critical for successful DSNC encapsulation.
• SEM revealed microspheres with coarse surfaces and porous internal structures.
• XRD confirmed no DSNC-PCL interaction, but a decrease in PCL crystallinity was observed with drug loading.
• Drug release exhibited an initial burst followed by sustained release, attributed to diffusion and osmotic pressure.

Conclusions:

• PCL microspheres are a viable system for DSNC delivery.
• The release mechanism involves both diffusion and osmotic pressure, influenced by the microsphere's porous structure.
• Optimizing dispersion viscosity is key for efficient DSNC encapsulation in PCL microspheres.