Structural evaluation of probucol nanoparticles in water by atomic force microscopy

Area of Science:

• Materials Science
• Pharmaceutical Technology
• Nanotechnology

Background:

• Probucol is a lipid-lowering drug with poor aqueous solubility.
• Nanoparticle formulations can enhance drug solubility and bioavailability.
• Solid-state characterization is crucial for understanding drug formulation stability.

Purpose of the Study:

• To structurally evaluate probucol nanoparticles coground with polyvinylpyrrolidone K17 and sodium dodecyl sulfate.
• To investigate the amorphous transformation and particle size of probucol after cogrinding.
• To assess the agglomeration behavior of probucol nanoparticles in aqueous suspension using AFM.

Main Methods:

• Solid-state nuclear magnetic resonance (NMR) spectroscopy was employed to analyze the crystalline-amorphous state of probucol.
• Atomic force microscopy (AFM) with force-distance curve analysis was used to determine particle size and evaluate agglomeration.
• Probucol nanoparticles were prepared by cogrinding with polyvinylpyrrolidone K17 and sodium dodecyl sulfate for 90 minutes.

Main Results:

• Solid-state NMR confirmed the conversion of crystalline probucol to an amorphous form upon cogrinding.
• AFM measurements showed number-averaged mean heights of 6 nm for freshly prepared probucol nanoparticles and 15 nm for 24h-stored samples.
• AFM identified the presence of probucol nanocrystals and particle agglomeration in aqueous suspension, suggesting nucleation and crystal growth.

Conclusions:

• Cogrinding effectively transforms probucol into an amorphous state, forming nanoparticles.
• Probucol nanoparticles undergo changes in size and agglomeration behavior upon dispersion in water.
• AFM is a valuable tool for characterizing nanoparticle structure and agglomeration in aqueous media.