Effects of amorphous silicon dioxides on drug dissolution

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Drug Delivery Systems

Background:

• Amorphous silicon dioxide is utilized as an excipient in drug formulations.
• Understanding drug-excipient interactions is crucial for optimizing drug dissolution and bioavailability.
• Different processing methods can significantly alter the physical properties of drug-excipient mixtures.

Purpose of the Study:

• To investigate the impact of amorphous silicon dioxide grades and processing techniques on the dissolution profiles of prednisone, digoxin, and griseofulvin.
• To elucidate the relationship between the physical characteristics of amorphous silicon dioxide and drug dissolution rates.
• To compare the effects of solvent deposition and ball milling on drug incorporation and particle size distribution.

Main Methods:

• Determined dissolution profiles of prednisone, digoxin, and griseofulvin in simulated gastrointestinal fluids.
• Employed solvent deposition and ball milling techniques for drug incorporation with three grades of amorphous silicon dioxide.
• Analyzed drug entrapment, dissolution rates, and particle size distribution.

Main Results:

• Solvent deposition led to drug entrapment, particularly with amorphous silicon dioxide grades having larger average pore diameters.
• Ball milling drugs with amorphous silicon dioxide possessing the largest average particle diameter resulted in the slowest dissolution rates.
• A correlation was observed between the extent of dilution with amorphous silicon dioxides and drug dissolution.
• Ball milling broadened particle size distribution more than solvent deposition.

Conclusions:

• The choice of amorphous silicon dioxide grade and processing method significantly influences drug dissolution.
• Larger pore diameters in amorphous silicon dioxide facilitate drug entrapment via solvent deposition.
• Ball milling, especially with larger particle size excipients, can reduce drug dissolution rates.
• These findings are critical for the rational design of solid dosage forms to control drug release.