Some factors influencing dissolution from salicylic acid-urea solid dispersions

Area of Science:

• Pharmaceutical Sciences
• Materials Science

Background:

• Solid dispersion systems are crucial for enhancing drug solubility and dissolution.
• The fusion method offers a solvent-free approach for preparing solid dispersions.
• Controlling particle size is key to optimizing drug release profiles.

Purpose of the Study:

• To investigate the effect of cooling methods on the solid dispersion of salicylic acid-urea.
• To analyze the influence of particle size on drug dissolution rates.

Main Methods:

• Preparation of salicylic acid-urea solid dispersions via fusion method.
• Employing rapid cooling (liquid nitrogen) and slow cooling (air) techniques.
• Characterization using Differential Scanning Calorimetry (DSC) and X-ray Diffraction (XRD).
• Measurement of drug dissolution rates from non-disintegrating discs.

Main Results:

• Evidence of compound formation between salicylic acid and urea was observed.
• Rapid cooling resulted in significantly faster drug dissolution rates compared to slow cooling.
• Rapid cooling produced smaller drug particles due to increased nucleation sites.
• Slow cooling led to larger drug particles due to preferential growth of existing nuclei.

Conclusions:

• The cooling rate of the melt critically influences the particle size and dissolution rate of salicylic acid-urea solid dispersions.
• Rapid cooling is a promising strategy for enhancing the dissolution performance of solid dispersions.
• Understanding particle formation mechanisms is essential for optimizing drug delivery systems.