Validation of a two-dimensional liquid chromatography method for quality control testing of pharmaceutical materials

Two-dimensional liquid chromatography with reversed phase in both dimensions: A review

Two-dimensional liquid chromatography (2D-LC), and in particular comprehensive two-dimensional liquid chromatography (LC×LC), offers increased peak capacity, resolution and selectivity compared to one-dimensional liquid chromatography. It is commonly accepted that the technique produces the best results when the separation mechanisms in the two dimensions are completely orthogonal; however, the use of similar separation mechanisms in both dimensions has been gaining popularity as it helps avoid difficulties related to mobile phase incompatibility and poor column efficiency. The remarkable advantages of using reversed phase in both dimensions (RPLC×RPLC) over other separation mechanisms made it a promising technique in the separation of complex samples. This review discusses some physical and practical considerations in method development for 2D-LC involving the use of RP in both dimensions. In addition, an extensive overview is presented of different applications that relied on RPLC×RPLC and 2D-LC with reversed phase column combinations to separate components of complex samples in different fields including food analysis, natural product analysis, environmental analysis, proteomics, lipidomics and metabolomics.

Simultaneous determination of favipiravir and surrogates of its metabolites by means of heart-cutting bidimensional liquid chromatography (2D-LC)

Therapeutic monitoring of drugs, particularly those with multiple metabolites, can be time-consuming and labor-intensive due to the need for different analytical methods depending on the specific metabolite or matrix of interest. In this study, we employed a heart-cutting 2D-LC separation method based on the coupling of reversed-phase and mixed-mode mechanisms to determine Favipiravir and surrogates of five main metabolites. This approach was applied to serum, plasma, urine, and human peripheral blood mononuclear cells. The method underwent validation to ensure its reliability. The findings highlight the potential of 2D-LC as a practical and efficient approach for therapeutic drug monitoring.

Unified chromatography in drug development: Exploiting chaotropic/kosmotropic salts for an accelerated method development

Recent trends in supercritical fluid chromatography (SFC) introduced an innovative gradient profile called Unified Chromatography (UC), which pushes the amount of liquid modifier up to 80-100 % of the total mobile phase composition. These new conditions allow the full transition from a supercritical to a liquid state, unifying the benefits of both SFC and liquid chromatography. However, to facilitate the use of UC for industrial drug development, a stronger effort is needed to streamline and simplify its method development and optimization. In this work, a quick and novel method development procedure for UC is introduced, enabled by the first-time use of novel additives in SFC/UC that exploit chaotropic/kosmotropic properties. A comprehensive view on some fundamental properties, such as the amount of liquid modifier blended with supercritical CO2 (scCO2) and the percentage of water added in the mobile phase is given, to clarify the benefits of using either a chaotropic salt (NaClO4), kosmotropic (HCOONa) or salt with mixed properties (NaOMs - sodium methanesulfonate). With this expanded knowledge, challenging separations of nucleosides, nucleotide, indoles, triazoles and related derivates have been accomplished with UC. Finally, we provide an example of UC delivering a faster and better method for an AbbVie pipeline compound under accelerated stability study. The combined use of scCO2-based chromatography and the novel additive NaClO4 ensures the retention and elution of all degradation species generated at different conditions, where RP-HPLC failed to provide satisfactory performance.

Trapping mode two-dimensional liquid chromatography for quantitative low-level impurity enrichment in pharmaceutical development

Trapping mode two-dimensional liquid chromatography (2D-LC) has recently found applications in pharmaceutical analysis to clean, refocus, and enrich analytes. Given its enrichment capability, 2D-LC with multiple trappings is appealing for low-level impurity monitoring that cannot be solved by single dimensional LC (1D-LC) or unenriched 2D-LC analysis. However, the quantitative features of multi-trapping 2D-LC remain largely unknown at impurity levels from parts-per-million (ppm) to 0.15% (w/w). We present a simple heart-cutting trapping mode 2D-LC workflow using only common components and software found in typical off-the-shelf 1D-LC instruments. This robust, turn-key system's quantitative capabilities were evaluated using a variety of standard markers, demonstrating linear enrichment for up to 20 trapping cycles and achieving a recovery of over 97.0%. Next, the trapping system was applied to several real-world low-level impurity pharmaceutical case studies including (1) the identification of two unknown impurities at sub-ppm levels resulting in material discoloration, (2) the discovery of a new impurity at 0.05% (w/w) co-eluted with a known impurity, making the undesired summation above the target specification, and (3) the quantification of a potential mutagenic impurity at 10-ppm level in a poorly soluble substrate. The recovery in all studies was better than 97.0% with RSD lower than 3.0%, demonstrating accuracy and precision of the 2D-LC trapping workflow. As no specialized equipment or software is required, we envision that the system could be used to develop low-impurity monitoring methods suitable for validation and potential execution in quality-control laboratories.

Emerging analytical techniques for pharmaceutical quality control: Where are we in 2022?

Quality control is a fundamental and critical activity in the pharmaceutical industry that guarantees the quality of medicines. QC analyses are currently performed using several well-known techniques, mainly liquid and gas chromatography. However, current trends are focused on the development of new techniques to reduce analysis time and cost, to improve the performances and decrease ecological footprint. In this context, analytical scientists developed and studied emerging technologies based on spectroscopy and chromatography. The present review aims to give an overview of the recent development of vibrational spectroscopy, supercritical fluid chromatography and multi-dimensional chromatography. Selected emerging techniques are discussed using SWOT analysis and published pharmaceutical QC applications are discussed.

Minimizing the Risk of Missing Critical Sample Information by Using Two-Dimensional Liquid Chromatography

Analytical requirements in the biopharmaceutical, pharmaceutical, and food industries, among several others, are more demanding than ever. Chromatographic techniques are great tools to acquire detailed information on a vast number of molecules and sample types. The present challenge in research and development (R&D), as well as in quality control (QC) laboratories, is to collect as much sample information as possible. However, even with the current one-dimensional (1D) analytical portfolio, it is not possible to fully ensure that all the relevant information from a sample has been captured. This article illustrates the power of an online two-dimensional liquid chromatographic (2D-LC) setup to unravel the complexity of biopharmaceutical and pharmaceutical samples. This technology tremendously increases the resolving power in all areas where LC is applied and drastically reduces the risk of missing information about the sample.

Development of a System Suitability Test for Two-Dimensional Liquid Chromatography

Verifying system performance is important when using chromatographic instrumentation for analyzing both known and unknown samples. Typically, system suitability tests (SSTs) are used to verify performance, which involves running an established method and comparing the results to pre-established acceptance criteria. As two-dimensional liquid chromatography (2D-LC) becomes used more widely and in regulated laboratory environments, development and implementation of SSTs will be critical for successful routine use of the 2D-LC technique.

Simultaneous separation of atenolol enantiomers and its acid/alkaline degradation impurities on mixed-mode chiral ligand exchange stationary phases

Simultaneous separation of the enantiomer and impurities is a huge challenge for the quality control of the chiral drug. In this work, mixed-mode chiral ligand exchange stationary phases (CSPs) modified by octyl and sulfhydryl ligands were prepared by vapor deposition and click chemistry methods. Qualitative and quantitative determination of the prepared CSPs were achieved by Fourier transform infrared spectroscopy, solid-state ¹³ C CP/MAS NMR, and elemental analysis. The chiral resolution of CSPs was investigated through a comprehensively chromatographic evaluation of various racemates. Besides, the thermodynamic experiment was carried out to elucidate the contribution of hydrophobic ligand to the improvement of chiral recognition and selectivity. Atenolol and its degradation products were analyzed on the synthesized CSPs and compared with the commercial chiral column. A good separation of atenolol enantiomers from its acid and alkaline degradation impurities was simultaneously achieved on the C₈ /L-Hypro CSP. This new CSP is expected to have more applications in the quality control of other chiral drugs.

Multi-column ultra-high performance liquid chromatography screening with chaotropic agents and computer-assisted separation modeling enables process development of new drug substances

Streamlined workflow for method development and optimization.

An overview of experimental designs in HPLC method development and validation

Chemometric approaches have been increasingly viewed as precious complements to high performance liquid chromatographic practices, since a large number of variables can be simultaneously controlled to achieve the desired separations. Moreover, their applications may efficiently identify and optimize the significant factors to accomplish competent results through limited experimental trials. The present manuscript discusses usefulness of various chemometric approaches in high and ultra performance liquid chromatography for (i) methods development from dissolution studies and sample preparation to detection, considering the progressive substitution of traditional detectors with tandem mass spectrometry instruments and the importance of stability indicating assays (ii) method validation through screening and optimization designs. Choice of appropriate types of experimental designs so as to either screen the most influential factors or optimize the selected factors' combination and the mathematical models in chemometry have been briefly recalled and the advantages of chemometric approaches have been emphasized. The evolution of the design of experiments to the Quality by Design paradigm for method development has been reviewed and the Six Sigma practice as a quality indicator in chromatography has been explained. Chemometric applications and various strategies in chromatographic separations have been described.