Microspherical Particles of Solid Dispersion of Polyvinylpyrrolidone K29-32 for Inhalation Administration

Area of Science:

• Pharmaceutical Technology
• Materials Science

Background:

• Inhalation drug delivery offers a non-invasive alternative to traditional methods.
• Achieving optimal particle size (1-3 μm) is crucial for effective aerosol drug preparation.
• Microspherical solid dispersions can improve the bioavailability of poorly soluble drugs.

Purpose of the Study:

• To optimize the spray drying process for producing microspherical solid dispersions of polyvinylpyrrolidone K29-32 and phenacetin.
• To evaluate the pharmaceutical properties of the resulting microspheres for inhalation administration.

Main Methods:

• Spray drying was employed to create microspherical solid dispersions.
• Differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and viscometry were used for optimization.
• Particle size analysis and dissolution rate studies were conducted.

Main Results:

• Optimized spray drying yielded particles with diameters in the 1-3 μm range.
• A polymer/phenacetin mass ratio of 5:1 resulted in a negative Gibbs energy of dissolution.
• Microspheres produced with 7.0 μm spray caps showed optimal size distribution for inhalation.
• Phenacetin remained in an amorphous state for at least 4 months within the microspheres.
• Dissolution rates were significantly faster compared to pure drug powder.

Conclusions:

• The spray drying process is effective for producing microspherical solid dispersions suitable for inhalation.
• This method enhances the solubility and dissolution rate of hydrophobic drugs like phenacetin.
• The amorphous state of phenacetin is maintained, contributing to improved pharmaceutical properties.