Are traditional small-scale screening methods reliable to predict pharmaceutical spray drying?

Area of Science:

• Pharmaceutical Sciences
• Chemical Engineering
• Materials Science

Background:

• Small-scale screening techniques are increasingly used for evaluating drug solubility and amorphous miscibility in polymers.
• These methods aim to reduce empiricism and build quality into pharmaceutical product development.
• However, their ability to predict the properties of spray-dried amorphous solid dispersions (ASDs) is questionable.

Purpose of the Study:

• To overview current small-scale screening techniques for drug-polymer systems.
• To identify the limitations of these methods in predicting spray-dried ASD properties.
• To introduce scaling rules to improve the prediction of ASD properties from small-scale experiments.

Main Methods:

• Literature review of small-scale screening techniques and spray drying processes.
• Analysis of spray drying operations, including atomization and drying, from a scaling perspective.
• Application of scaling rules to address limitations in conventional miniaturized tools.

Main Results:

• Inconsistencies were found in predicting ASD properties using conventional small-scale methods.
• Miniaturized techniques often fail to simulate the complex operations and constraints of spray drying.
• Scaling rules offer a potential solution to bridge the gap between small-scale testing and spray drying performance.

Conclusions:

• Current small-scale screening methods have liabilities in predicting spray-dried ASD properties.
• Understanding and applying scaling principles to atomization and drying is crucial for accurate prediction.
• Further development of scale-up strategies can enhance the success rate of ASD formulations.