Static vs. Dynamic Electrostatic Repulsion Reversed Phase Liquid Chromatography: Solutions for Pharmaceutical and Biopharmaceutical Basic Compounds

Assessing the performance of new chromatographic technologies for the separation of peptide epimeric impurities: the case of Icatibant

The biopharmaceutical industry faces the challenge of efficiently characterising impurity profiles of therapeutical peptides, also due to their complex polar and ionisable attributes. This research explores the potential of advanced chromatographic techniques to address this challenge. The study compares dynamic electrostatic repulsion reversed phase (d-ERRP) to its counterparts (static ERRP and ion pair reversed phase IP-RP) in analysing Icatibant and its elusive epimeric impurity, [L-Arg]1-Icatibant and highlights its exceptional capabilities in generating symmetric peaks, mitigating the common tailing phenomenon, and serving as a steadfast guardian of column longevity. The result highlights d-ERRP as a pioneering tool in the domain of liquid chromatography, fostering its role as a reference technique for the analysis of therapeutic peptides.

Development of HPLC Method for Simultaneous Determination of Ibuprofen and Chlorpheniramine Maleate

One of the most prevalent over-the-counter cold and cough medications is the chlorpheniramine maleate (CPM)–ibuprofen (IBF) combination. A reversed-phase high-performance liquid chromatography (RP-HPLC) method was effectively optimized and developed for the simultaneous detection of chlorpheniramine maleate and ibuprofen in a pharmaceutical formulation. The mobile phase for the RP-HPLC method was an isocratic combination of acetonitrile and 0.01 M acetate buffer at pH 3.8 (55:45; v/v) on an Eclipse Plus C18 reversed phase column. An ultraviolet (UV) detector with a wavelength of 225 nm was used to detect the analytes at a flow rate of 1.0 mL/min. CPM and IBF were satisfactorily eluted, with mean retention times of 2.09 and 6.27 min, respectively. The approach was shown to be linear (R2 > 0.9998 for CPM and 0.9992 for IBF), precise (% RSD 3.02% for CPM and 3.48% for IBF), accurate (% recoveries 97.7–98.9% for CPM and 101–104.5% for IBF), specific, easy to use, sensitive, quick, and robust. Limits of detection (LODs) were found to be 10 and 27 μg/mL for CPM and IBF, respectively. Without interference from excipients, the validated method could be utilized in regular quality control analysis of various dosage combinations of hard gelatin capsules containing CPM and IBF.

Expanding the Use of Dynamic Electrostatic Repulsion Reversed-Phase Chromatography: An Effective Elution Mode for Peptides Control and Analysis

Bioactive peptides are increasingly used in clinical practice. Reversed-phase chromatography using formic or trifluoroacetic acid in the mobile phase is the most widely used technique for their analytical control. However, sometimes it does not prove sufficient to solve challenging chromatographic problems. In the search for alternative elution modes, the dynamic electrostatic repulsion reversed-phase was evaluated to separate eight probe peptides characterised by different molecular weights and isoelectric points. This technique, which involves TBAHSO4 in the mobile phase, provided the lowest asymmetry and peak width at half height values and the highest in peak capacity (about 200 for a gradient of 30 min) and resolution concerning the classic reversed-phase. All analyses were performed using cutting-edge columns developed for peptide separation, and the comparison of the chromatograms obtained shows how the dynamic electrostatic repulsion reversed-phase is an attractive alternative to the classic reversed-phase.