Analytical control strategies for mutagenic impurities: Current challenges and future opportunities?

Photodegradation of indomethacin and naproxen contained within commercial products for skin - RAP

Patient can be exposed to the photodegradation products of a drug after skin application of topical formulations. NSAIDs, with analgesic and anti-inflammatory properties, are known for the potential photoinstability, and are applied often in the form of creams, gels or liquids, commonly used among athletes, elderly people, geriatric patients and patients treated with multidrug therapies. Susceptibility to photodegradation hazard of those group arises the need for development of a new approach, with the ability to evaluate the patient safety. We planned to use a rapid assessment procedure (RAP) of safety by testing the photostability of popular skin medicinal products. This method, proposed many years ago by WHO, is now reintroduced to analytical applications in industry, when emergency drugs (e.g. for Covid) are implemented to the market in accelerated procedures. In the health care system, qualitative evaluation of drugs is extremely valuable, therefore we have planned to identify photodegradation using the FTIR method - infrared spectroscopy and DSC - differential scanning calorimetry, whilst the risk of formation of genotoxic products using the Ames test. We have successfully demonstrated that changes in the chemical structure and physical form of both pure APIs and drug products containing the API be assessed in a short time. Another advantage of our work is the combination of the developed results from FTIR/NIR spectra with statistical analysis. As a result, full and quick qualitative assessment of the effects of photoexposure of selected NSAIDs is performed, fortunately showing no mutagenicity. Due to the popularity of NSAIDs applied to the skin, a gel containing naproxen and spray with indomethacin were selected for testing. The analysis carried out for various formulations of both preparations allows us to demonstrate the universality of the applied RAP methods in assessing the risk of hazard to the patient, thus we present research results that expand or widen the knowledge and assessment of risks related to the use of drugs on the skin.

A rapid and sensitive UPLC-MS/MS method for simultaneous determination of four potential mutagenic impurities at trace levels in ripretinib drug substance

In the synthesis of ripretinib, a new oral tyrosine kinase inhibitor, impurities could arise directly from starting materials, reagents and intermediates. Among these process impurities, four specific intermediate impurities were found to contain the structural alerts of primary aromatic amine and aldehyde groups, triggering the concern of potential mutagenic impurities (PMIs). Two complementary (quantitative) structure-activity relationship [(Q)SAR] evaluation systems (expert rule-based and statistics-based) were subsequently employed to assess and classify the mutagenic risk of the four known impurities. The Sarah prediction results of these four impurities were all positive and they were categorized as class 3, where the threshold of toxicological concern (TTC) of 1.5 μg d-1 would apply. Hereby, a rapid and sensitive UPLC-MS/MS method was developed for the simultaneous and trace level quantification of the four PMIs in ripretinib drug substance. The separation was achieved on a C18 column under the optimized gradient elution program consuming only nine minutes and the four PMIs were all well separated from ripretinib so that they could be easily diverted to waste via a switch valve. The time-segmented multiple reaction monitoring (MRM) mode further improved the sensitivity and allowed for the quantification of the four PMIs as low as 10% of the acceptable limit. The method was fully validated, and proved sufficient in terms of selectivity, sensitivity, linearity, precision and accuracy. The factors involved in the method development and pathways for fragment ions of the four PMIs were also discussed and the study will contribute to risk management of PMIs present in ripretinib.

Determination of Methyl Methanesulfonate and Ethyl Methylsulfonate in New Drug for the Treatment of Fatty Liver Using Derivatization Followed by High-Performance Liquid Chromatography with Ultraviolet Detection

A new derivatization high-performance liquid chromatography method with ultraviolet detection was developed and validated for the quantitative analysis of methanesulfonate genotoxic impurities in an innovative drug for the treatment of non-alcoholic fatty liver disease. In this study, sodium dibenzyldithiocarbamate was used as a derivatization reagent for the first time to enhance the sensitivity of the analysis, and NaOH aqueous solution was chosen as a pH regulator to avoid the interference of the drug matrix. Several key experimental parameters of the derivatization reaction were investigated and optimized. In addition, specificity, linearity, precision, stability, and accuracy were validated. The determined results of the samples were consistent with those obtained from the derivatization gas chromatography–mass spectrometry analysis. Thus, the proposed method is a reliable and practical protocol for the determination of trace methanesulfonate genotoxic impurities in drugs containing mesylate groups.

Chemical Characterization and Non-targeted Analysis of Medical Device Extracts: A Review of Current Approaches, Gaps, and Emerging Practices

The developers of medical devices evaluate the biocompatibility of their device prior to FDA's review and subsequent introduction to the market. Chemical characterization, described in ISO 10993-18:2020, can generate information for toxicological risk assessment and is an alternative approach for addressing some biocompatibility end points (e.g., systemic toxicity, genotoxicity, carcinogenicity, reproductive/developmental toxicity) that can reduce the time and cost of testing and the need for animal testing. Additionally, chemical characterization can be used to determine whether modifications to the materials and manufacturing processes alter the chemistry of a patient-contacting device to an extent that could impact device safety. Extractables testing is one approach to chemical characterization that employs combinations of non-targeted analysis, non-targeted screening, and/or targeted analysis to establish the identities and quantities of the various chemical constituents that can be released from a device. Due to the difficulty in obtaining a priori information on all the constituents in finished devices, information generation strategies in the form of analytical chemistry testing are often used. Identified and quantified extractables are then assessed using toxicological risk assessment approaches to determine if reported quantities are sufficiently low to overcome the need for further chemical analysis, biological evaluation of select end points, or risk control. For extractables studies to be useful as a screening tool, comprehensive and reliable non-targeted methods are needed. Although non-targeted methods have been adopted by many laboratories, they are laboratory-specific and require expensive analytical instruments and advanced technical expertise to perform. In this Perspective, we describe the elements of extractables studies and provide an overview of the current practices, identified gaps, and emerging practices that may be adopted on a wider scale in the future. This Perspective is outlined according to the steps of an extractables study: information gathering, extraction, extract sample processing, system selection, qualification, quantification, and identification.

Analytical Method Lifecycle Management in Pharmaceutical Industry: a Review

The adoption of Quality by Design (QbD) and Analytical Method Lifecycle Management (AMLM) concepts to ensure the quality of pharmaceutical products has been applied and proposed over the last few years. These concepts are based on knowledge gained from the application of scientific and quality risk management approaches, throughout method lifecycle to assure continuous improvement and high reliability of analytical results. The overall AMLM starts with the definition of the method's intended use through the Analytical Target Profile definition, including three stages: (1) Method Design, taking advantage of the well-known concept of QbD; (2) Method Performance Qualification; (3) Continued Method Performance Verification. This is intended to holistically align method variability with product requirements, increasing confidence in the data generated, a regulatory requirement that the pharmaceutical industry must follow. This approach views all method-related activities, such as development, validation, transfer, and routine use as a continuum and interrelated process, where knowledge and risk management are the key enablers. An increase in method robustness, cost reduction, and decreased risk failures are some of the intrinsic benefits from this lifecycle management. This approach is clearly acknowledged both by regulators and industry. The roadmap of the regulatory and industry events that mark the evolution of these concepts helps to capture the current and future expectation of the pharmaceutical framework.

Selective quantitation of B2Pin2 and B2(OH)4 in active pharmaceutical ingredients by gas chromatography- mass spectrometry

This paper describes a sensitive and selective method for the simultaneous determination of bispinacolato diboron (B₂Pin₂) and tetrahydroxy diboron (B₂(OH)₄) in a small molecule Active Pharmaceutical Ingredient (API) by gas chromatography - mass spectrometry (GC-MS). These reagents are commonly used in the Suzuki-Miyaura coupling reaction and analytical methods are typically required to monitor these reagents at the Threshold of Toxicological Concern (TTC) level since they are Class II impurities based on ICH M7 guideline. In this study, hexylene glycol was added to derivatize B₂(OH)₄ before direct injection to the GC-MS, and B₂Pin₂ is analyzed in the same analysis without derivatization. Under the optimal conditions, the limit of detection (LOD) and the limit of quantitation (LOQ) were 65 ng/mL and 130 ng/mL respectively. Average recoveries of the analytes spiked in the drug substance at the 13 ppm (LOQ) and 104 ppm (TTC) levels were in the range of 77.9 %-85.3 % with relative standard deviations (RSDs) of 2.8 %-6.8 %. The linearity for both analytes was established in the range of 0.130-2.080 μg/mL with a correlation coefficient (r) of 0.9998 and the derivatization reaction is very rapid and complete within 15 minutes.

Simultaneous Determination of 15 Sulfonate Ester Impurities in Phentolamine Mesylate, Amlodipine Besylate, and Tosufloxacin Tosylate by LC-APCI-MS/MS

Sulfonate esters have been recognized as potential genotoxic impurities (PGIs) in pharmaceuticals. An LC-MS/MS method was developed and validated for the simultaneous determination of 15 sulfonate esters, including methyl, ethyl, propyl, isopropyl, and n-butyl esters of methanesulfonate, benzenesulfonate, and p-toluenesulfonate in drug products. The method utilized atmospheric pressure chemical ionization (APCI) in multiple reaction monitoring (MRM) mode for the quantitation of impurities. The method employed an ODS column as the stationary phase and water-acetonitrile as the solvents for gradient elution without derivatization steps. The method was specific, linear, accurate, precise, and robust. Recoveries of the sulfonic esters from three drug matrices were observed in the range of 91.6∼109.0% with an RSD of not greater than 17.9% at the concentration of the LOQ and in the range of 90.4%∼105.2% with an RSD of not greater than 7.1% at the concentration of 50 ng/mL for the methanesulfonates and 10 ng/mL for the benzenesulfonates and p-toluenesulfonates. The LOD was not greater than 15 ng/mL, 2 ng/mL, and 1 ng/mL for the methanesulfonate, benzenesulfonate, and p-toluenesulfonate esters, respectively. This method was sufficiently sensitive to detect the 15 PGIs in the phentolamine mesylate tablet, amlodipine besylate tablet, and tosufloxacin tosylate tablet. This analytical method is a direct, specific, rapid, and accurate quality control tool for the determination of the 15 sulfonate esters that are most likely to exist in drug products.