A sensitive ultra-performance liquid chromatography-tandem mass spectrometry method for the simultaneous quantification of assay and trace-level genotoxic tosylate analogs (methyl and ethyl) in empagliflozin and its tablet dosage forms.

This study performed the simultaneous quantification of assay and two alkyl sulfonate (tosylate) analogs of empagliflozin (EGZ), specifically methyl 4-methyl benzene sulfonate (MMBS) and ethyl 4-methyl benzene sulfonate (EMBS) in EGZ, and its finished dosage form using an accurate and sensitive ultra-performance liquid chromatography-mass spectrometry method. The separation was achieved on a Waters Acquity BEH Shield RP18 (100 × 2.1 mm, 1.7 µm) column in gradient elution mode with 0.1% formic acid and acetonitrile as the mobile phases and a flow rate of 0.5 mL/min. For simultaneous quantification, the multiple reaction monitoring technique was utilized. The procedure was successfully validated in accordance with the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines. The peak areas of both impurities, along with their concentrations, exhibited a good relationship with Pearson's correlation coefficient (R), which was >0.999 in the range of 0.3-6 ppm with an EGZ concentration of 2 mg/mL. The percentage recoveries from the limit of quantitation (LOQ) to 200% to the specification level were in the range of 94.82%-102.92%, whereas the percentage relative standard deviation (%RSD) was <2. Therefore, this method is rapid and accurate to quantify MMBS, EMBS, and EGZ assay simultaneously from the marketed tablet dosage forms of EGZ for commercial release and stability sample testing.

Establishing a multi-method approach for unprecedented detection and quantification of 13 genotoxic impurities (GTIs) in Apixaban drug substance through ultra-performance liquid chromatography (UPLC).

This groundbreaking study introduces a pioneering development of multi-method approach for the first-ever detection and quantification of 13 genotoxic impurities (GTIs) in Apixaban (Apx) drug substance using ultra-performance liquid chromatography (UPLC) with ultraviolet (UV) detector. In this novel endeavor, two distinct UPLC-UV methods, Method A (for impurities A to G) and Method B (for impurities H to M), were meticulously developed and validated as per International Council for Harmonization (ICH) guidelines to address the challenge of identification and control of 13 GTIs in Apx drug substance. The validation process included rigorous assessment of linearity, accuracy, specificity, precision, limit of quantification (LOQ), and limit of detection (LOD) for each impurity in each method which marks a significant advancement in pharmaceutical analysis. The developed methods address the regulatory requirements set forth by ICH M7(R2) guidelines by providing a reliable approach for quantifying GTIs in Apx drug substance at trace levels to minimize the potential carcinogenic risk to the patients.

Method for trace determination of N-nitrosamines impurities in metronidazole benzoate using high-performance liquid chromatography coupled with atmospheric-pressure chemical ionization tandem mass spectrometry.

Genotoxic impurity control has been a great concern in the pharmaceutical industry since the recall of the large round of sartans worldwide in 2018. In these sartans, N-nitrosamines were the main contaminants in active pharmaceutical ingredients and formulations. Numerous analytical methods have been developed to detect N-nitrosamines in food, drugs, and environmental samples. In this study, a sensitive method is developed for the trace determination of N-nitrosamine impurities in metronidazole benzoate pharmaceuticals using high-performance liquid chromatography/atmospheric-pressure chemical ionization tandem mass spectrometry in the multiple reaction monitoring mode. The method was validated regarding system suitability, selectivity, linearity, accuracy, precision, sensitivity, solution stability, and robustness. The method showed good linearity with R2 ≥ 0.999 and FMandel  < Ftab(95%) ranging from 0.33 to 8.00 ng/ml. The low limits of detection of N-nitrosamines were in the range of 0.22-0.80 ng/ml (0.0014-0.0050 ppm). The low limits of quantification were in the range of 0.33-1.20 ng/ml (0.0021-0.0075 ppm), which were lower than the acceptable limits in metronidazole benzoate pharmaceuticals and indicated the high sensitivity of the method. The recoveries of N-nitrosamines ranged from 84% to 97%. Thus, this method exhibits good selectivity, sensitivity, and accuracy. Moreover, it is a simple, convenient, and scientific strategy for detecting N-nitrosamine impurities in pharmaceuticals to support the development of the pharmaceutical industry.

Trace-level determination of potential genotoxic impurities in quetiapine fumarate using LC-MS.

A novel LC-MS method was developed and validated to determine three potential genotoxic impurities, namely 2-(2-aminophenylthio)benzoic acid hydrochloride, 2-aminothiophenol, and 2-(2-aminophenylthio)benzonitrile, at trace level (~1.6 ppm) in quetiapine fumarate drug substance, an antipsychotic drug. These impurities are potentially genotoxic and therefore should be controlled at or below specific acceptance limits. An InertSustain AQ-C18 column (250 × 4.6 mm, 5 µm) in reversed-phase mode with the column temperature at 45°C was used. The mobile phase was 0.1% trifluoroacetic acid in water and acetonitrile with gradient elution mode, and the run time was 45 min. The flow rate was 0.8 ml/min. A mass spectrometer was used to quantify the amount of impurities using electrospray ionization mode at specific m/z 245.9, 126.0, and 226.9 for 2-(2-aminophenylthio)benzoic acid hydrochloride, 2-aminothiophenol, and 2-(2-aminophenylthio) benzonitrile, respectively. The method was found to be sensitive and possessed excellent linearity in the concentration ranges from the limit of quantification to 150% of the permitted level (0.47-2.36 µg/ml) with correlation coefficients above 0.999. The results showed that the method was specific, precise, linear, and accurate for the estimation of these three impurities in quetiapine fumarate.

Identification and validation of potential genotoxic impurities, 1,3-dichloro-2-propanol, and 2,3-dichloro-1-propanol, at subtle levels in a bile acid sequestrant, colesevelam hydrochloride, using hyphenated GC-MS technique.

Potential genotoxic impurities (PGI) and N-nitrosamine impurities in active pharmaceutical ingredients (APIs) and their determination at low levels are substantial challenges for cholesterol-lowering agents in recent years. Herein we developed a robust, reliable, rapid, accurate and validated technique of gas chromatography equipped with a mass spectrometer (GC-MS) for quantifying subtle levels of 1,3-dichloro-2-propanol (PGI-I) and 2,3-dichloro-1-propanol (PGI-II) in colesevelam hydrochloride drug substance (bile acid sequestrant). The separation of colesevelam hydrochloride, PGI-I and PGI-II was executed with chromatographic technique using a capillary column, DB-624 measuring with 30 m × 0.32 mm × 1.8 µm specification of 6% cyanopropylphenyl-94% dimethylpolysiloxane copolymer and helium carrier gas. This developed technique gave a good intensity peak without any interference and extra masses at the retention times of 11.17 min for PGI-I and 11.59 min for PGI-II, which was adequate, with mass spectra (m/z) of 79 and 62, respectively. The method's sensitivity and linearity are demonstrated by its detection and quantification limits at subtle levels with correlation coefficients of 0.9965 for PGI-I and 0.9910 for PGI-II. The determination is mainly focused on improving sensitivity with the limits of detection and quantitation far below the specifications, which can support tighter limits. This results in a cost-effective and easily adoptable methodology having precise and accurate results in colesevelam hydrochloride API at subtle levels.

Highly sensitive spectrofluorimetric method for the determination of the genotoxic methylglyoxal in glycerol-containing pharmaceuticals and dietary supplements.

Methylglyoxal (MGO) is a genotoxic α-dicarbonyl compound. Recently, it was found to be formed in glycerol preparations during storage through auto-oxidation. A simple fluorimetric determination of the carcinogenic degradation product of glycerol, MGO, was developed and validated. The proposed method is based on the derivatization of MGO with 4-carbomethoxybenzaldehyde (CMBA) and ammonium acetate to yield a fluorescent imidazole derivative that can be measured at 415 nm after excitation at 322 nm. The optimized conditions were determined to be 0.2 M CMBA, 1.0 M ammonium acetate and a reaction time of 40 min at 90°C using ethanol as diluting solvent. The linear range was 10.0-200.0 ng/ml. Detection and quantification limits were 2.22 and 6.72 ng/ml, respectively. The proposed method was validated according to International Council for Harmonisation (ICH) guidelines and compared with the reported method and no significant difference was found. It was successfully applied for the determination of MGO in six different glycerol-containing pharmaceutical preparations and dietary supplements.

A sensitive LC-MS/MS method for the determination of potential genotoxic impurities in Cinnarizine.

A highly sensitive LC-MS/MS method for the trace level determination of genotoxic impurities, Cinnamyl chloride and Benzhydryl chloride, in Cinnarizine drug substance was developed and validated. Chromatographic separation was successfully achieved on Atlantis d C18 column with dimensions 150× 4.6mm and particle size: 5µm. 0.1% Trifluoroacetic acid in water and 100% acetonitrile was used as mobile phases with gradient mode of elution at 1.0mL/min flow rate. Mass spectroscopic detection was carried out with selective ion monitoring (SIM) technique in positive mode at m/z 117 and 167 for Cinnamyl chloride and Benzhydryl chloride respectively. Developed method was proven to be selective, sensitive, and precise for the quantification of potential genotoxic impurities in Cinnarizine by validating as per the regulatory guidelines. The LOD and LOQ values observed for Cinnamyl chloride were 0.49 and 1.47ppm and for Benzhydryl chloride 0.55 and 1.67ppm respectively. Precision of the method at LOQ level was shown with good % RSD of 4.21. Method was proven linear from LOQ to 150% level with a correlation of 0.996 and accurate with a range of recovery from 86.4 to 100.8%. This highly sensitive method can be used to control both the genotoxic impurities in Cinnarizine drug substance by LC-MS/MS.

Angiotensin-converting enzyme inhibitors for ovarian cancer? - a new adjuvant option or a silent trap.

Background: Ovarian cancer is a huge therapeutic and financial problem for which approved treatments have already achieved their limit of efficiency. A cost-effective strategy to extend therapeutic options in this malignancy is drug repurposing aimed at overcoming chemoresistance. Here, angiotensin-converting enzyme inhibitors (ACE-I) are worth considering. Materials and methods: We searched literature for publications supporting the idea of adjuvant application of ACE-Is in ovarian malignancy. Then, we searched The Cancer Genome Atlas databases for relevant alternations of gene expression patterns. We also performed in silico structure-activity relationship evaluation for predicting ACE-Is' cytotoxicity against ovarian cancer cell lines. Finally, we reviewed the potential obstacles in ACE-Is repurposing process. Results: The alternation of angiotensin receptor expression in ovarian cancer translates into poorer patient survival. This confirms the participation of the renin-angiotensin system in ovarian carcinogenesis. In observational studies, ACE-Is were shown synergize with both, platinum-based chemotherapy as well as with antiangiogenic therapy. Consistently, our in silico simulation showed that ACE-Is are probably cytotoxic against ovarian cancer cells. However, the publications on their chemopreventive properties were inconclusive. In addition, some reports correlated ACE-Is use with increased general cancer incidence. We hypothesized that this effect could be associated with mutagenic nitrosamine formation in ACE-Is' pharmaceutical formulations, as was the case with angiotensin receptor blockers (ARBs) and other well-established pharmaceuticals. Conclusions: Available data warrant further research into repositioning ACE-Is to ovarian cancer as chemosensitizers. Prior to this, however, a special research program is needed to detect possible genotoxic contaminants of ACE-Is.

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.

Quantitative Determination of Four Potential Genotoxic Impurities in the Active Pharmaceutical Ingredients in TSD-1 Using UPLC-MS/MS.

A novel method of ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed for the identification and quantification of four potential genotoxic impurities (PGIs) in the active pharmaceutical ingredients of TSD-1, a novel P2Y12 receptor antagonist. Four PGIs were named, 4-nitrobenzenesulfonic acid, methyl 4-nitrobenzenesulfonate, ethyl 4-nitrobenzenesulfonate, and isopropyl 4-nitrobenzenesulfonate. Following the International Conference of Harmonization (ICH) guidelines, this methodology is capable of quantifying four PGIs at 15.0 ppm in samples of 0.5 mg/mL concentration. This validated approach presented very low limits (0.1512−0.3897 ng/mL), excellent linearity (coefficients > 0.9900), and a satisfactory recovery range (94.9−115.5%). The method was sufficient in terms of sensitivity, linearity, precision, accuracy, selectivity, and robustness and, thus, has high practicality in the pharmaceutical quality control of TSD-1.

Liquid chromatography-mass spectrometric methods for trace quantification of potential genotoxic impurities in ivacaftor and lumacaftor.

OBJECTIVE: The objective of the current study was to develop and validate the sensitive LC-MS methods for trace analysis of genotoxic impurities in Ivacaftor and Lumacaftor. The first method is for the trace analysis of 2,4-di-tert-butyl-5-nitrophenol in ivacaftor and the second method is for the trace analysis of 1-(2,2-difluoro-1,3-benzodioxol-5yl)-cyclopropane carboxylic acid and 3-carboxyphenyl boronic acid in lumacaftor. MATERIALS AND METHODS: High pure analytical grade solvents and reagents were used for this study. The chromatographic separation was performed on Luna C18 (250×4.6mm, 5.0µm) at a column temperature of 25°C using eluent consisting of acetonitrile and 0.1% v/v formic acid in water in a gradient elution mode. The eluent was run at a flow of 1.0mL/min and injection volume of 20µL. RESULTS: The linearity, precision and accuracy of the developed methods was validated over the concentration range of 0.35-15.0ppm for 2,4-di-tert-butyl-5-nitrophenol, 0.30-15.0ppm for 1-(2,2-difluoro-1,3-benzodioxol-5yl)-cyclopropane carboxylic acid and 0.23-15.0ppm for 3-carboxyphenyl boronic acid. In both methods, interference was not observed at the retention time of analyte peaks. All the analytes were found to be stable in solution for a period of 48h. CONCLUSION: The proposed methods are reliable, sensitive, precise, accurate, and robust for the trace level quantification of genotoxic impurities in Ivacaftor and Lumacaftor. These methods can be successfully implemented in the quality control lab for routine analysis.

Identification, isolation, characterization, and UHPLC quantification of potential genotoxic impurities in linagliptin.

During the stress testing of linagliptin, one unknown degradation product (impurity I) on acidic conditions was detected by using high-performance liquid chromatography and subsequently isolated, identified, and characterized by the spectral data (MS, MS/MS, 1D and 2D NMR spectroscopy, and IR spectroscopy) and finally subjected for mechanism analysis. The degradation product (impurity I) and another process-related impurity (impurity II) of linagliptin were found to contain the structural alerts of N-acylated aminoaryl and alkyl halide, respectively, which were both potential genotoxic substances. Hence, a rapid and facile ultra high performance liquid chromatography method was developed for the simultaneous determination of these two potential genotoxic impurities at ppm levels in linagliptin. The factors involved in the method development were discussed and this method was fully validated as per International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use guidelines, which proved the method sensitive, selective, and robust. The presented method has been successfully applied to the analysis of real samples from multiple batches. This study will help to risk management of possible genotoxic impurities present in linagliptin.

Characterization of imatinib mesylate formulations distributed in South American countries: Determination of genotoxic impurities by UHPLC-MS/MS and dissolution profile.

Imatinib mesylate (IM) is an anti-neoplasic drug used for the treatment of cancer. Recent new guidelines specify daily doses and concentration limits for genotoxic impurities (GTIs) in pharmaceutical final products. Therefore, in this work an analytical method using UHPLC-MS/MS was developed, validated and applied to characterize IM tablets for two GTIs: N-(2-methyl-5-aminophenyl)-4-(3-pyridyl)-2-pyrimidine amine (Imp. 1), and N-[4-methyl-3-(4-methyl-3-yl-pyrimidin-2-ylamino)-phenyl]-4- chloromethyl benzamide (Imp. 2), simultaneously. Additionally, dissolution data of IM tablets were compared using a methodology recommended by the US Food and Drug Administration. The UHPLC method utilized an Acquity BEH C18 (150 × 2.1 mm, 1.7 µm) maintained at 40°C. The mobile phase consisted of ammonium formate 0.063% (phase A) and acetonitrile plus 0.05% formic acid (phase B) in gradient elution. A sensitive method for determination of previously mentioned GTIs in IM tablets was successfully developed and applied. Overall, the formulations analyzed in this work showed low levels of Imp. 1 and Imp. 2. However, the sample named D1 showed very high levels of Imp. 1 and failed to meet the requirements established by the US Food and Drug Administration for dissolution data. Periodic verification of GTIs in pharmaceutical formulations is important to minimize safety risks, so analytical methods to determine it need be available and implemented in routine analysis.

An investigation of the mutagenic activity of salamide - a major impurity of hydrochlorothiazide.

Hydrochlorothiazide is a widely used antihypertensive agent and one of its major impurities, salamide (4-amino-6-chlorobenzene-1,3-disulphonamide), has a chemical structure containing a primary amino group, a functional group that has previously been reported to be associated with carcinogenic activity. It is known that hydrochlorothiazide purity is a challenging problem for the pharmaceutical industry. As there were no prior mutagenicity data for the impurity salamide, the aim was to investigate its mutagenicity in this study. Salamide was tested for mutagenic potential in Salmonella typhimurium TA98, TA100, TA 1535, TA 1537, and E. coli WP2 uvrA + E. coli WP2 [pKM101] strains at six different concentrations, the highest concentration being the 5000 µg/plate. In both the presence and absence of the metabolic activation system, no mutagenic activity was observed. Results indicated that salamide should be classified as an ordinary impurity and controlled according to Q3A(R2) and Q3B(R2) guidelines.

A practical application of two in silico systems for identification of potentially mutagenic impurities.

The International Conference on Harmonization (ICH) M7 guidance for the assessment and control of DNA reactive impurities in pharmaceutical products includes the use of in silico prediction systems as part of the hazard identification and risk assessment strategy. This is the first internationally agreed guidance document to include the use of these types of approaches. The guideline requires the use of two complementary approaches, an expert rule-based method and a statistical algorithm. In addition, the guidance states that the output from these computer-based assessments can be reviewed using expert knowledge to provide additional support or resolve conflicting predictions. This approach is designed to maximize the sensitivity for correctly identifying DNA reactive compounds while providing a framework to reduce the number of compounds that need to be synthesized, purified and subsequently tested in an Ames assay. Using a data set of 801 chemicals and pharmaceutical intermediates, we have examined the relative predictive performances of some popular commercial in silico systems that are in common use across the pharmaceutical industry. The overall accuracy of each of these systems was fairly comparable ranging from 68% to 73%; however, the sensitivity of each system (i.e. how many Ames positive compounds are correctly identified) varied much more dramatically from 48% to 68%. We have explored how these systems can be combined under the ICH M7 guidance to enhance the detection of DNA reactive molecules. Finally, using four smaller sets of molecules, we have explored the value of expert knowledge in the review process, especially in cases where the two systems disagreed on their predictions, and the need for care when evaluating the predictions for large data sets.

Determination of genotoxic impurities of aromatic aldehydes in pharmaceutical preparations by high performance liquid chromatography after derivatization with N-Cyclohexyl-4-hydrazino-1,8-naphthalenediimide.

The detection of aromatic aldehydes, considered potential genotoxic impurities, holds significant importance during drug development and production. Current analytical methods necessitate complex pre-treatment processes and exhibit insufficient specificity and sensitivity. This study presents the utilization of naphthalenediimide as a pre-column derivatisation reagent to detect aromatic aldehyde impurities in pharmaceuticals via high-performance liquid chromatography (HPLC). We screened a series of derivatisation reagents through density functional theory (DFT) and investigated the phenomenon of photoinduced electron transfer (PET) for both the derivatisation reagents and the resulting products. Optimal experimental conditions for derivatisation were achieved at 40 °C for 60 min. This approach has been successfully applied to detect residual aromatic aldehyde genotoxic impurities in various pharmaceutical preparations, including 4-Nitrobenzaldehyde, 2-Nitrobenzaldehyde, 1,4-Benzodioxane-6-aldehyde, and 5-Hydroxymethylfurfural. The pre-column derivatisation method significantly enhanced detection sensitivity and reduced the limit of detection (LOD), which ranged from 0.002 to 0.008 µg/ml for the analytes, with relative standard deviations < 3 %. The correlation coefficient (R2) >0.998 demonstrated high quality. In chloramphenicol eye drops, the concentration of 4-Nitrobenzaldehyde was measured to be 8.6 µg/mL below the specified concentration, with recoveries ranging from 90.0 % to 119.2 %. In comparison to existing methods, our work simplifies the pretreatment process, enhances the sensitivity and specificity of the analysis, and offers comprehensive insights into impurity detection in pharmaceutical preparations.

Impurity study of tecovirimat.

This article delineates the systematic identification, synthesis, and impurity control methods used during the manufacturing process development of tecovirimat, an antiviral drug that treats monkeypox. Critical impurities were synthesized, and their chemical structure was confirmed through NMR analysis, GC, and HPLC mass spectrometry. The results established a thorough approach to identify, address, and control impurities to produce high-quality tecovirimat drug substance in accordance with International Conference on Harmonization (ICH)-compliant standards. This study is the first of its kind to evaluate both process and genotoxic impurities in tecovirimat, demonstrating effective control measures during commercial sample investigations and scaling up to a 60-kg batch size. The findings highlight the importance of critical impurity characterization and control in pharmaceutical development and production to ensure the safety and efficacy of the final product.

Preparation and optimization of dummy molecularly imprinted polymer-based solid-phase extraction system for selective enrichment of p-toluene sulfonate esters genotoxic impurities.

Sulfonate esters, one class of genotoxic impurities (GTIs), have gained significant attention in recent years due to their potential to cause genetic mutations and cancer. In the current study, we employed the dummy template molecular imprinting technology with a dummy template molecule replacing the target molecule to establish a pretreatment method for samples containing p-toluene sulfonate esters. Through computer simulation and ultraviolet-visible spectroscopy analysis, the optimal functional monomer acrylamide and polymerization solvent chloroform were selected. Subsequently, a dummy template molecularly imprinted polymer (DMIP) was prepared by the precipitation polymerization method, and the polymer was characterized in morphology, particle size, and composition. The results of the adsorption and enrichment study demonstrated that the DMIP has high adsorption capability (Q = 7.88 mg/g) and favorable imprinting effects (IF = 1.37); Further, it could simultaneously adsorb three p-toluene sulfonate esters. The optimal adsorption conditions were obtained by conditional optimization of solid-phase extraction (SPE). A pH 7 solution was selected as the loading condition, the methanol/1 % phosphoric acid solution (20:80, v/v) was selected as the washing solution, and acetonitrile containing 10 % acetic acid in 6 mL was selected as the elution solvent. Finally, we determined methyl p-toluene sulfonate alkyl esters, ethyl p-toluene sulfonate alkyl esters, and isopropyl p-toluene sulfonate alkyl esters in tosufloxacin toluene sulfonate and capecitabine at the 10 ppm level (relative to 1 mg/mL active pharmaceutical ingredient (API) samples) by using DMIP-based SPE coupled with HPLC. This approach facilitated the selective enrichment of p-toluene sulfonate esters GTIs from complex API samples.

Identification and simultaneous quantification of potential genotoxic impurities in first-line HIV drug dolutegravir sodium using fast ultrasonication-assisted extraction method coupled with GC-MS and in-silico toxicity assessment.

Dolutegravir (DLG) has become a distinctive first-line antiretroviral therapy for the treatment of HIV in most countries due to its affordability, high efficacy, and low drug-drug interactions. However, the evaluation of genotoxic impurities (GTIs) in DLG and their toxicity assessment has not been explored thoroughly. Thus, in this study, a simple, fast, and selective analytical methodology was developed for the identification and determination of 7 GTIs in the comprehensive, explicit route of synthesis for the dolutegravir sodium (DLG-Na) drug. A facile, fast ultrasonication-assisted liquid-liquid extraction procedure was adapted to isolate the GTIs in DLG-Na and then analyzed using the gas chromatography (GC)-electron impact (EI)/mass spectrometer (MS) quantification (using selective ion monitoring mode) technique. This EI-GC/MS method was validated as per the current requirements of ICH Q2 (R1) guidelines. Under optimal method conditions, excellent linearities were achieved with R between 0.9959 and 0.9995, and high sensitivity was obtained in terms of detection limits (LOD) between 0.15 to 0.63 µg/g, and quantification limits (LOQ) between 0.45 to 1.66 µg/g for the seven GTIs in DLG. The obtained recoveries ranged from 98.2 to 104.3 % at LOQ, 15 µg/g, and 18 µg/g concentration levels (maximum daily dose of 100 mg). This developed and validated method is rapid, easy to adopt, specific, sensitive, and accurate in estimating the seven GTIs in a relatively complex sodium matrix of the DLG-Na drug moiety. As a method application, two different manufactured samples of DLG-Na drug substances were analyzed for the fate of the GTIs and drug safety for the intended dosage applications. Moreover, an in-silico QSAR toxicity prediction assessment was carried out to prove scientifically the potential GTI nature of each impurity from the alerting functional groups.

A comprehensive approach for N-nitrosamine determination in pharmaceuticals using a novel HILIC-based solid phase extraction and LC-HRMS.

N-nitrosamines (NAs) are potentially highly carcinogenic compounds that have recently been detected in traces in various drug products (DPs). Due to the different physicochemical properties of NAs and active pharmaceutical ingredients (APIs), there is a lack of appropriate analytical methods for simultaneously determining multiple NAs in various DPs. To overcome these limitations, a versatile and innovative analytical approach was developed using a unique sample clean-up procedure by solid phase extraction based on hydrophilic interaction chromatography, which retains high amounts of APIs and polar excipients while allowing NAs of interest to pass through. The samples were analyzed by liquid chromatography coupled with electrospray ionization high-resolution mass spectrometry. The proposed highly sensitive, selective, and robust method was successfully validated, resulting in excellent linearity (R2 > 0.999), accuracy (85-115 %), and precision (RSD <10 %) with adequate recoveries (>80 %), achieving limits of quantitation of at least 42.5 % of regulatory limits. Furthermore, robustness was confirmed for ten DPs (recoveries >80 % and RSD <15 % for all NAs), including those containing up to three APIs. The analytical approach was utilized to examine 26 commercially available and expired DPs. Three NAs (N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine, and N-nitroso-di-n-butylamine) were detected, only NDMA exceeded the limits in expired DPs by up to 32-fold. It was found that special care should be taken when handling samples as NDMA content can be decreased by almost 50 % if samples are not prepared immediately. The approach was tested on 59 different APIs and was confirmed as reliable tool for routine monitoring of 15 NAs in various DPs. Due to its flexibility, the method can be further adapted to the specific API of interest or extended to the newly emerging NA drug substance-related impurities to ensure the safety of DPs and thereby mitigate potential health risks.