Liquid Chromatography-High Resolution Mass Spectrometry for Peptide Drug Quality Control

High-throughput method for Peptide mapping and Amino acid sequencing for Calcitonin Salmon in Calcitonin Salmon injection using Ultra High Performance Liquid Chromatography - High Resolution Mass Spectrometry (UHPLC-HRMS) with the application of Bioinformatic tools

BACKGROUND

Tandem mass spectrometry (MS/MS) can provide direct and accurate sequence characterization of synthetic peptide drugs, and peptide drug products including side chain modifications in the Peptide drugs. This article explains a step-by-step guide to developing a high-throughput method using high resolution mass spectrometry for characterization of Calcitonin Salmon injection containing high proportion of UV-active excipients.

METHODS

The major challenge in the method development of Amino acid sequencing and Peptide mapping was presence of phenol in drug product. Phenol is a UV-active excipient and reacts with both Dithiothreitol (DTT) and Trypsin. Hence Calcitonin Salmon was extracted from the Calcitonin Salmon injection using solid phase extraction after the extraction, Amino acid sequencing and peptide mapping study was performed. Upon incubation of Calcitonin Salmon with Trypsin and DTT, digested fragments were generated which were separated by mass compatible reverse phase chromatography and the molecular mass of each fragment was determined using HRMS.

RESULTS

A reverse phase chromatographic method was developed using UHPLC-HRMS for the determination of direct mass, peptide mapping and to determine the amino acid sequencing in the Calcitonin Salmon injection. The method was found Specific and fragments after trypsin digest are well resolved from each other and the molecular mass of each fragment was determined using HRMS. Sequencing was performed using automated identification of b and y ions annotation and identifications based on MS/MS spectra using Biopharma finder and Proteome discoverer software.

CONCLUSION

Using this approach 100% protein coverage was obtained and protein was identified as Calcitonin Salmon and the observed masses of tryptic digest of peptide was found similar with theoretical masses. The method can be used for both UV and MS based Peptide mapping and whereas the UV based peptide mapping method can be used as identification test for Calcitonin Salmon drug substance and drug product in quality control.

Qualification of a LC-HRMS platform method for biosimilar development using NISTmab as a model

Biosimilars are a cost-effective alternative to biopharmaceuticals, necessitating rigorous analytical methods for consistency and compliance. Liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) is a versatile tool for assessing key attributes, encompassing molecular mass, primary structure, and post-translational modifications (PTMs). Adhering to ICH Q2R1, we validated an LC-HRMS based peptide mapping method using NISTmab as a reference. The method validation parameters, covering system suitability, specificity, accuracy, precision, robustness, and carryover, were comprehensively assessed. The method effectively differentiated the NISTmab from similar counterparts as well as from artificially introduced spiked conditions. Notably, the accuracy of mass error for NISTmab specific complementarity determining region peptides was within a maximum of 2.42 parts per million (ppm) from theoretical and the highest percent relative standard deviation (%RSD) observed for precision was 0.000219 %. It demonstrates precision in sequence coverage and PTM detection, with a visual inspection of total ion chromatogram approach for variability assessment. The method maintains robustness when subjected to diverse storage conditions, encompassing variations in column temperature and mobile phase composition. Negligible carryover was noted during the carryover analysis. In summary, this method serves as a versatile platform for multiple biosimilar development by effectively characterizing and identifying monoclonal antibodies, ultimately ensuring product quality.

An overview of in vitro and in vivo techniques for characterization of intranasal protein and peptide formulations for brain targeting

The surge in neurological disorders necessitates innovative strategies for delivering active pharmaceutical ingredients to the brain. The non-invasive intranasal route has emerged as a promising approach to optimize drug delivery to the central nervous system by circumventing the blood-brain barrier. While the intranasal approach offers numerous advantages, the lack of a standardized protocol for drug testing poses challenges to both in vitro and in vivo studies, limiting the accurate interpretation of nasal drug delivery and pharmacokinetic data. This review explores the in vitro experimental assays employed by the pharmaceutical industry to test intranasal formulation. The focus lies on understanding the diverse techniques used to characterize the intranasal delivery of drugs targeting the brain. Parameters such as drug release, droplet size measurement, plume geometry, deposition in the nasal cavity, aerodynamic performance and mucoadhesiveness are scrutinized for their role in evaluating the performance of nasal drug products. The review further discusses the methodology for in vivo characterization in detail, which is essential in evaluating and refining drug efficacy through the nose-to-brain pathway. Animal models are indispensable for pre-clinical drug testing, offering valuable insights into absorption efficacy and potential variables affecting formulation safety. The insights presented aim to guide future research in intranasal drug delivery for neurological disorders, ensuring more accurate predictions of therapeutic efficacy in clinical contexts.

Metabolism and Chemical Degradation of New Antidiabetic Drugs: A Review of Analytical Approaches for Analysis of Glutides and Gliflozins

The drug metabolism and drug degradation pathways may overlap, resulting in the formation of similar constituents. Therefore, the metabolism data can be helpful for deriving safe levels of degradation impurities and improving the quality of respective pharmaceutical products. The present article contains considerations on possible links between metabolic and degradation pathways for new antidiabetic drugs such as glutides, gliflozins, and gliptins. Special attention was paid to their reported metabolites and identified degradation products. At the same time, many interesting analytical approaches to conducting metabolism as well as degradation experiments were mentioned, including chromatographic methods and radioactive labeling of the drugs. The review addresses the analytical approaches elaborated for examining the metabolism and degradation pathways of glutides, i.e., glucagon like peptide 1 (GLP-1) receptor agonists, and gliflozins, i.e., sodium glucose co-transporter 2 (SGLT2) inhibitors. The problems associated with the chromatographic analysis of the peptide compounds (glutides) and the polar drugs (gliflozins) were addressed. Furthermore, issues related to in vitro experiments and the use of stable isotopes were discussed.

Characterization of Synthetic Peptide Therapeutics Using Liquid Chromatography-Mass Spectrometry: Challenges, Solutions, Pitfalls, and Future Perspectives

Synthetic peptides represent an important and expanding class of therapeutics. Despite having a relatively small size as compared to monoclonal antibodies and other proteins, synthetic peptides are subject to many complex structural modifications originating from the starting materials, manufacturing process, and storage conditions. Although mass spectrometry has been increasingly used to characterize impurities of synthetic peptides, systematic review of this field is scarce. In this paper, an overview of the impurities in synthetic peptide therapeutics is provided in the context of how the knowledge from detailed characterization of the impurities using liquid chromatography-mass spectrometry (LC-MS) can be used to develop the manufacturing process and control strategy for synthetic peptide therapeutics following the critical quality attribute (CQA)-driven and risk-based approach. The thresholds for identifying and controlling the impurities are discussed based on currently available regulatory guidance. Specific LC-MS techniques for identification of various types of impurities based on their structural characteristics are discussed with the focus on structural isomers and stereoisomers (i.e., peptide epimers). Absolute and relative quantitation methods for the peptide impurities are critiqued. Potential pitfalls in characterization of synthetic peptide therapeutics using LC-MS are discussed. Finally, a systematic LC-MS workflow for characterizing the impurities in synthetic peptide therapeutics is proposed, and future perspectives on applying emerging LC-MS techniques to address the remaining challenges in the development of synthetic peptide therapeutics are presented.

Combination of continuous digestion by peptidase and spectral similarity comparisons for peptide sequencing

Peptide sequencing is critical to the quality control of peptide drugs and functional studies of active peptides. A combination of peptidase digestion and mass spectrometry technology is common for peptide sequencing. However, such methods often cannot obtain the complete sequence of a peptide due to insufficient amino acid sequence information. Here, we developed a method of generating full peptide ladders and comparing their MS² spectral similarities. The peptide ladders, of which each component was different from the next component with one residue, were generated by continuous digestion by peptidase (carboxypeptidase Y and aminopeptidase). Then, based on the characteristics of peptide ladders, complete sequencing was realized by comparing MS² spectral similarity of the generated peptide ladders. The complete amino acid sequences of bivalirudin, adrenocorticotropic hormone, and oxytocin were determined with high accuracy. This approach is beneficial to the quality control of drug peptides as well as the identification of novel bioactive peptides.

Impurities identification and quantification for calcitonin salmon by liquid chromatography-high resolution mass spectrometry

Calcitonin salmon is an important peptide pharmaceutical, which is mainly used for the treatment of osteoporosis and hypercalcemia. Structurally related peptide impurities in a peptide pharmaceutical probably have side effect or even toxicity, thus needs to be carefully characterized according to pharmacopoeia. With the improvement of analytical techniques, liquid chromatography-high resolution mass spectrometry (LC-HRMS) has become a pivotal technique for the identification and quantification of structurally related peptide impurities in peptide materials. In this study, an LC-HRMS-based method has been developed for the identification and quantification of structurally related peptide impurities in calcitonin salmon material. With this method, 7 peptide impurities (> 1 mg/g) in United States Pharmacopoeia (USP) reference standard and 9 peptide impurities (> 1 mg/g) in European Pharmacopoeia (EP) reference standard were identified and accurately quantified. Besides the peptide impurities reported by USP and EP, several new impurities such as [7-Dehydroalanine] calcitonin salmon, triple-sulfate-calcitonin salmon, [26-Proline] calcitonin salmon, [14-Glutamic acid] calcitonin salmon, [20-Glutamic acid] calcitonin salmon, [26-Aspartic acid] calcitonin salmon, calcitonin salmon acid were observed in the reference standard materials studied. The total mass fractions of all structurally related peptide impurities in calcitonin salmon study materials were estimated to be 57.4 mg/g for USP and 46.3 mg/g for EP with associated expended uncertainties at a 95 % confidence level of 5.2 mg/g (k = 2) and 3.1 mg/g (k = 2), respectively.

Impurity identification and quantification for arginine vasopressin by liquid chromatography/high-resolution mass spectrometry

RATIONALE

For pharmaceutical quality control, impurities may have unexpected pharmacological or toxicological effects on quality, safety, and efficacy of drugs. Arginine vasopressin (AVP) is an important cyclic peptide drug that is mainly used for the treatment of diabetes insipidus and esophageal varices bleeding. With the advancement made in analytical techniques, liquid chromatography/high-resolution mass spectrometry (LC/HRMS) has emerged as a critical technique for the identification and quantification of structurally related peptide impurities in AVP.

METHODS

An LC/HRMS/MS-based method using a quadrupole ion trap-Orbitrap mass spectrometer operated in the positive ion electrospray ionization mode was developed for the determination and quantification of structurally related peptide impurities in AVP.

RESULTS

Under optimized experimental conditions, three deamidation products, ([Glu⁴ ]AVP, [Asp⁵ ]AVP, and AVP acid), two amino acid deletion impurities (des-Pro⁷ -AVP and des-Gly⁹ -AVP), one amino acid insertion impurity (endo-Gly^10a -AVP), one end chain reaction product (N-acetyl-AVP), and one AVP isomer were detected. Subsequent quantification using an external standard method estimated the total mass fraction of all structurally related peptide impurities in the AVP study material to be 30.3 mg/g with an expanded uncertainty of 3.0 mg/g (k = 2).

CONCLUSIONS

This study complements the AVP impurity profile and improves the separation and discovery of other potential impurities in vasopressin analogues.

Innovation for Generic Drugs: Science and Research Under the Generic Drug User Fee Amendments of 2012

Regulatory science is science and research intended to improve decision making in a regulatory framework. Improvements in decision making can be in both accuracy (making better decisions) and in efficiency (making faster decisions). Science and research supported by the Generic Drug User Fee Amendments of 2012 (GDUFA) have focused on two innovative methodologies that work together to enable new approaches to development and review of generic drugs: quantitative models and advanced in vitro product characterization. Quantitative models faithfully represent current scientific understanding. They are tools pharmaceutical scientists and clinical pharmacologists use for making better and faster product development decisions. Advances in the in vitro product comparisons provide the measurements of product differences that are the critical input into the models. This paper outlines four areas where science and research funded by GDUFA support synergistic use of models and characterization at critical decision points during generic drug product development and review.

Purity assignment for peptide certified reference materials by combining qNMR and LC-MS/MS amino acid analysis results: application to angiotensin II

The purity value assignment of metrologically traceable peptide reference standards requires specialized primary methods. Conventionally, amino acid analysis by isotope dilution tandem mass spectrometry (LC-MS/MS) following peptide hydrolysis is employed as a reference method. By contrast, quantitative nuclear magnetic resonance (qNMR) spectroscopy allows for quantitation of intact peptides, thus eliminating potential bias due to hydrolysis. Both methods are susceptible to interference from related peptide impurities, which need to be accurately measured and accounted for. The mass balance approach has also been employed for peptide purity measurements, whereby the purity is defined by the sum of the mass fraction of all impurities identified. Ideally, results from these three orthogonal methods can be combined for final purity assignment of peptide reference standards. Here we report a novel strategy for correcting both LC-MS/MS and ¹H-qNMR results for related peptide impurities and combining results from both methods using a Bayesian statistical approach using mass balance results as prior knowledge. The mass balance method relied on a validated ¹⁹F-qNMR method to measure the trifluoroacetic acid (TFA) counter-ion, considered an impurity in this case at nearly 25% by mass. Using a candidate certified reference material (CRM) for angiotensin II, excellent agreement was achieved with the three methods. The final purity value assignment of the candidate CRM was 691 ± 9 mg/g (k = 2).

Performance metrics for evaluating system suitability in liquid chromatography--Mass spectrometry peptide mass mapping of protein therapeutics and monoclonal antibodies

The use of liquid chromatography--mass spectrometry (LC-MS) for the characterization of proteins can provide a plethora of information related to their structure, including amino acid sequence determination and analysis of posttranslational modifications. The variety of LC-MS based applications has led to the use of LC-MS characterization of therapeutic proteins and monoclonal antibodies as an integral part of the regulatory approval process. However, the improper use of an LC-MS system, related to intrinsic instrument limitations, improper tuning parameters, or poorly optimized methods may result in the production of low quality data. Improper system performance may arise from subtle changes in operating conditions that limit the ability to detect low abundance species. To address this issue, we systematically evaluated LC-MS/MS operating parameters to identify a set of metrics that can be used in a workflow to determine if a system is suitable for its intended purpose. Development of this workflow utilized a bovine serum albumin (BSA) digest standard spiked with synthetic peptides present at 0.1% to 100% of the BSA digest peptide concentration to simulate the detection of low abundance species using a traditional bottom-up workflow and data-dependent MS(2) acquisition. BSA sequence coverage, a commonly used indicator for instrument performance did not effectively identify settings that led to limited dynamic range or poorer absolute mass accuracy on 2 separate LC-MS systems. Additional metrics focusing on the detection limit and sensitivity for peptide identification were determined to be necessary to establish system suitability for protein therapeutic characterization by LC-MS.