Analytical techniques for quantification of amorphous/crystalline phases in pharmaceutical solids

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Analytical Chemistry

Background:

• Pharmaceuticals exist in various solid-state forms, including amorphous, crystalline, solvates, and hydrates.
• Amorphous systems offer unique advantages in drug formulation, influencing drug product properties and biological performance.
• Accurate identification and quantification of solid-state forms are critical for predicting material behavior during storage and handling.

Purpose of the Study:

• To review existing analytical techniques for the quantitative analysis of amorphous and crystalline phases in pharmaceutical materials.
• To provide a compilation of theoretical and practical aspects of these quantification methods.
• To assist formulation scientists in selecting appropriate techniques for amorphous system quantification.

Main Methods:

• Literature review of analytical techniques for amorphous/crystalline phase quantification.
• Discussion of theoretical principles underlying different quantitative methods.
• Evaluation of practical considerations, including accuracy, precision, and suitability.

Main Results:

• Numerous analytical techniques exist for quantifying amorphous/crystalline phases, each with varying properties evaluated.
• Different techniques can yield divergent crystallinity values for the same sample.
• The choice of technique impacts the accuracy, precision, and suitability of the results.

Conclusions:

• Quantitative analysis of physical state is essential for manufacturing and regulatory control of drug products.
• Selecting the appropriate technique is crucial for reliable quantification of amorphous systems.
• This review facilitates informed technique selection for diverse quantification objectives.