Influence of API physico-chemical properties on amorphization capacity of several mesoporous silica loading methods

Area of Science:

• Materials Science
• Pharmaceutical Technology
• Chemical Engineering

Background:

• Mesoporous silica (MS) is a key material for drug delivery systems.
• Optimizing drug loading into MS requires understanding drug-silica interactions.
• Physico-chemical properties of drugs influence loading efficiency and amorphization.

Purpose of the Study:

• To evaluate how drug physico-chemical properties affect mesoporous silica loading.
• To identify optimal loading methods for enhanced drug penetration and amorphization.
• To compare various impregnation techniques for drug-silica formulation.

Main Methods:

• Six model drugs (lidocaine, ibuprofen, ketoprofen, artemether, miconazole) with diverse properties were used.
• Impregnation methods included physical mixing, melting, wetting, supercritical CO2 (sc-CO2), and subcritical CO2.
• Drug recovery and crystallinity were assessed for each formulation.

Main Results:

• Loading efficiency approached 100% for most methods, with exceptions for sc-CO2 soluble drugs.
• Basic drug character minimized drug loss during impregnation.
• Supercritical processing of insoluble drugs reduced crystallinity, enhancing pore penetration.

Conclusions:

• Drug physico-chemical properties are critical for selecting appropriate mesoporous silica loading methods.
• Melting and subcritical CO2 methods show promise for high drug loading, especially for viscous drugs.
• A variety of loading techniques can yield highly loaded MS formulations.