Development of tandem-column liquid chromatographic methods for pharmaceutical compounds using simulations based on...

Area of Science:

• Analytical Chemistry
• Pharmaceutical Analysis
• Chromatography

Background:

• Liquid chromatography (LC) is vital for analyzing pharmaceutical compounds and impurities, but achieving separation is difficult due to structural similarities.
• Tandem-column LC (TC-LC) provides enhanced selectivity over single-column methods but requires extensive column screening.

Purpose of the Study:

• To develop and validate a computational workflow for selecting optimal column configurations in TC-LC for pharmaceutical analysis.
• To compare the critical resolution (Rc) of single-column versus TC-LC separations for small molecule pharmaceuticals and impurities.

Main Methods:

• Experimentally determined hydrophobic subtraction model (HSM) solute parameters for Linrodostat and its impurities.
• Utilized HSM column parameters to simulate and predict critical resolution (Rc) for numerous single and tandem column combinations.
• Validated predictions through experimental LC separations.

Main Results:

• A workflow using HSM simulations successfully predicted effective column configurations for separating a complex mixture.
• One tandem column configuration achieved complete baseline resolution, outperforming single-column methods in both predicted and experimental Rc values.
• The study demonstrated the significant selectivity potential of TC-LC and validated the predictive accuracy of the HSM-based workflow.

Conclusions:

• The proposed workflow significantly reduces the time and resources needed for column selection in TC-LC by prioritizing combinations computationally.
• TC-LC offers substantial advantages in selectivity for challenging pharmaceutical separations compared to conventional single-column approaches.
• Further improvements in prediction accuracy are possible, but the current workflow provides a valuable tool for accelerating method development.