Method development for pharmaceutics: some solutions for tuning selectivity in reversed phase and hydrophilic...

Area of Science:

• Analytical Chemistry
• Chromatography
• Pharmaceutical Analysis

Background:

• Selecting optimal liquid chromatography (LC) conditions is challenging due to numerous variables affecting selectivity.
• Reversed-Phase Liquid Chromatography (RPLC) and Hydrophilic Interaction Liquid Chromatography (HILIC) offer distinct separation mechanisms.
• Understanding parameter influence on selectivity is crucial for effective pharmaceutical method development.

Purpose of the Study:

• To experimentally evaluate the impact of stationary phases, mobile phase pH, and organic modifiers on selectivity in RPLC and HILIC.
• To demonstrate the complementarity of RPLC and HILIC for analyzing diverse pharmaceutical compounds.
• To apply optimized RPLC and HILIC methods for drug cocktail and impurity profiling.

Main Methods:

• Analysis of 45 pharmaceutical compounds with varying physicochemical properties under RPLC and HILIC conditions.
• Utilized Principal Component Analysis (PCA) to model and assess the multivariate experimental dataset.
• Employed RPLC and HILIC for drug cocktail analysis (substrates and metabolites) and impurity profiling.

Main Results:

• Complementarity between RPLC and HILIC was experimentally demonstrated, showing distinct elution orders for compounds.
• Mobile phase pH was identified as a critical factor significantly influencing chromatographic selectivity.
• Successful resolution of complex mixtures, including drug metabolites and impurities, was achieved in both RPLC and HILIC modes.

Conclusions:

• RPLC and HILIC are complementary techniques valuable for pharmaceutical method development, offering distinct separation capabilities.
• Optimization of mobile phase pH and careful selection of stationary phases are essential for achieving desired selectivity.
• The study confirms the utility of RPLC and HILIC for comprehensive analysis of pharmaceutical compounds and their related substances.