Detection of APIs in Pharmaceutical formulations using ARL X’TRA Companion X-ray Diffractometer

Importance of the topic

X-ray diffraction (XRD) plays a pivotal role in pharmaceutical analysis by revealing crystalline structures and polymorphs of active pharmaceutical ingredients (APIs) and excipients. Accurate phase identification and purity assessment underpin product safety, efficacy and regulatory compliance.

Objectives and Study Overview

This study demonstrates the detection and quantification of resveratrol in hydroxypropyl methylcellulose (HPMC) matrices using the Thermo Scientific ARL X'TRA Companion X-ray Diffractometer. Key goals include establishing the limit of detection (LoD) and evaluating method robustness for routine quality control applications.

Methodology and Instrumentation

• Instrument: ARL X'TRA Companion X-ray Diffractometer in Bragg-Brentano geometry with a θ/θ goniometer, 600 W Cu source, radial and axial collimation and integrated solid-state pixel detector.
• Software: Profex for data processing and Rietveld quantification; crystallography open database (COD) for theoretical peak matching.
• Samples: Pure HPMC and mixtures containing 1 wt.% and 5 wt.% resveratrol, measured in reflection mode with Cu Kα radiation, zero-background holder, 30 min acquisition and sample spinning.

Main Results and Discussion

Distinct resveratrol diffraction peaks were identified down to 1 wt.% against HPMC background. Linear regression analysis yielded an LoD of approximately 0.2 wt.% (3× standard error). The instrument’s fast data acquisition and automated Rietveld fitting enabled reliable phase quantification and detection of low-level APIs and polymorphic forms.

Practical Benefits and Applications

The ARL X'TRA Companion XRD offers rapid, high-throughput API identification and quantification within complex formulations, supporting stringent QA/QC workflows. One-click Rietveld analysis and LIMS integration streamline data reporting and compliance with regulatory standards, enhancing formulation development and batch release processes.

Future Trends and Potential Applications

Emerging directions include integration with machine learning for automated phase recognition, in situ monitoring of crystallization and dissolution, and expanded use in characterizing amorphous materials and polymorph screening. Advances in detector technology and software will further improve sensitivity and workflow automation.

Conclusion

This application note highlights the capability of the ARL X'TRA Companion XRD to detect APIs at sub-percent levels in pharmaceutical formulations, delivering fast, accurate and automated analyses essential for modern pharmaceutical quality control.

Reference

1. N. Döbelin, R. Kleeberg, J. Appl. Crystallogr. 2015, 48, 1573-1580.
2. F. Caruso et al., J. Agric. Food Chem. 2004, 52, 7279-7285.