Solid dispersion prepared by continuous cogrinding in an air jet mill.

Area of Science:

• Pharmaceutical Technology
• Materials Science
• Chemical Engineering

Background:

• Enhancing the dissolution rate of poorly water-soluble drugs is crucial for improving bioavailability.
• Continuous manufacturing processes are gaining traction in pharmaceutical production, moving beyond traditional batch methods.
• Solid dispersions and cogrinding are established techniques for drug formulation optimization.

Purpose of the Study:

• To investigate the efficacy of continuous cogrinding using a jet mill for preparing solid dispersions of poorly water-soluble drugs.
• To elucidate the mechanisms behind the enhanced dissolution rate of drugs processed via continuous cogrinding.
• To compare the physicochemical properties and dissolution behavior of coground formulations with physical mixtures.

Main Methods:

• Continuous cogrinding of griseofulvin (drug) and mannitol (hydrophilic carrier) using a jet mill.
• Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD) for structural analysis.
• Contact angle measurements and Confocal Raman microscopy for surface energy and dispersity analysis.
• Dissolution testing and application of the Hixson-Crowell model to assess dissolution enhancement.

Main Results:

• A drug load of 10% griseofulvin in mannitol was optimal for enhanced dissolution.
• Continuous cogrinding resulted in a rapidly dissolving, yet crystalline, drug formulation.
• Particle size reduction was not the primary factor for dissolution enhancement; increased surface free energies and bulk dispersity were key.
• The coground dispersion exhibited superior dissolution behavior compared to physical mixtures.

Conclusions:

• Continuous cogrinding in a jet mill is a viable and promising technique for producing solid dispersions with enhanced drug dissolution rates.
• The enhanced dissolution is attributed to increased surface free energies and improved drug dispersity within the hydrophilic carrier.
• This approach offers an efficient continuous manufacturing method for optimizing the performance of poorly water-soluble drugs.