Biorelevant Dissolution Method Considerations for the Appropriate Evaluation of Amorphous Solid Dispersions: are Two...

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery
• Biopharmaceutics

Background:

• Biorelevant dissolution testing simulates gastrointestinal (GI) conditions to predict drug performance.
• Conventional methods often fail to accurately capture dissolution, supersaturation, and precipitation for amorphous solid dispersions (ASDs).
• This limitation can lead to misinformed ASD formulation screening and optimization.

Purpose of the Study:

• To develop and validate a novel 2-stage pH-shift dissolution method for improved biorelevant testing.
• To compare the efficacy of the new method against conventional single-stage dissolution testing.
• To provide guidance for selecting appropriate biorelevant dissolution methods for various ASD formulations.

Main Methods:

• Developed a single compartment, 2-stage pH-shift dissolution testing method simulating GI tract conditions.
• Selected nine model drugs based on ionization properties and precipitation rates.
• Compared results from the 2-stage method with a conventional 1-stage method.

Main Results:

• The 2-stage pH-shift method demonstrated superior accuracy in assessing drug behavior compared to the 1-stage method.
• This method is particularly effective for non-ionized weak bases and neutral compounds with moderate precipitation rates from ASDs.
• Confirmed suitability for specific drugs like nifedipine and griseofulvin formulated as ASDs.

Conclusions:

• The 2-stage pH-shift dissolution method is the preferred approach for evaluating biorelevant dissolution of certain ASDs.
• This advanced method enhances the reliability of ASD formulation screening and optimization.
• A flowchart was developed to guide the selection of appropriate biorelevant dissolution characterization for diverse ASDs.