Impurities In Drug Substances Research Articles

Two genotoxic impurities of sulfonate esters in Posaconazole: Synthesis, method validation and mechanism of action

AbstractSulfonate esters are a class of organic impurities that includes highly potent mutagenic substances that typically need to be controlled down to a low ppm level in pharmaceutical development. In this work, two genotoxic impurities of sulfonate esters in Posaconazole, for example, ((3S,5R)‐5‐((1H‐1,2,4‐triazol‐1‐yl)methyl)‐5‐(2,4‐difluorophenyl)tetrahydrofuran‐3‐yl)methyl‐4‐methylbenzenesulfonate and (2S,3S)‐3‐ (4‐(4‐(4‐(4‐(((3R,5R)‐5‐((1H‐1,2,4‐triazol‐1‐yl)methyl)‐5‐(2,4‐difluorophenyl)tetrahydrofuran‐3‐yl)methoxy)phenyl)piperazin‐1‐yl)phenyl)‐5‐oxo‐4,5‐dihydro‐1H‐1,2,4‐triazol‐1‐yl)pentan‐2‐yl‐4‐methylbenzenesulfonate, were synthesized and characterized. The genotoxicity which was evaluated by two (quantitative) structure‐activity relationships prediction methodologies showed positive. Furthermore, a novel high‐performance liquid chromatography‐tandem mass spectrometry limit test method for detecting these two impurities in Posaconazole has been established and validated. The chromatographic separation of analytes was conducted on an ACQUITY BEH C18 column, and performed with 0.05% methanoic acid‐water and 0.05% methanoic acid‐acetonitrile as mobile phases A and B, respectively. Six batches of commercial‐scale Posaconazole samples were detected by the validated method and the results were in accordance with the Food and Drug Administration acceptance criteria for the genotoxic impurities in drug substances. Finally, a tentative mechanism for these two impurities was proposed, they are generally accepted to undergo an SN2‐type reaction, resulting in 7‐methylguanine as the predominant adduct in double‐stranded DNA.

Impurity assessment, development and validation of an RP-HPLC method for the determination of eleven potential impurities of eltrombopag precursor

Eltrombopag is an oral non-peptide thrombopoietin receptor (TPO-R) agonist indicated for the treatment of thrombocytopenia in patients with persistent or chronic immune thrombocytopenia (idiopathic thrombocytopenic purpura, ITP) or chronic hepatitis C infection and the treatment of severe aplastic anemia. The purpose of this research was to assess the possible impurities that may carry over to eltrombopag from its precursor Eltro-1 (3′-amino-2′-hydroxy-[1,1′-biphenyl]-3-carboxylic acid) and to develop a specific analytical method for the determination of these impurities. Eltro-1 samples synthesized by two different synthesis routes were investigated during the evaluation and method development studies. Besides the expected process-related impurities (Eltro-1A – Eltro‐1J), e.g., starting materials, intermediates, and/or compounds formed from their further reactions, an unknown impurity detected above 0.10% was identified by LC-MS, synthesized and fully characterized by NMR, MS and FTIR (Eltro‐1K). Accordingly, an HPLC-RP method for the determination of eleven impurities (Eltro-1A – Eltro‐1K) in Eltro-1 was developed and validated according to ICH Q2. The control limits for impurities in Eltro-1 were set at ≤ 0.15% for Eltro-1A – Eltro‐1J and ≤ 1.0% for Eltro‐1K based on fate, spike-purge and carryover studies and in accordance with the ICH M7 classification for impurities in drug substance. Eltro-1 and eleven impurities at the specification limit were separated from each other and the diluent peaks with sufficient resolution without interference. Separation was performed on a Waters XBridge C18 column (150 × 4.6 mm, 3.5 μm) at 40 °C with a 10 µL injection volume at a detection wavelength of 220 nm and 15 °C sample temperature. The gradient elution is performed at a flow rate of 1.0 mL/min for 40 min with mobile phase A (0.1% orthophosphoric acid in water) and B (acetonitrile) according to the following program: Time (min) / Acetonitrile (%): 0/0, 35/70, 36/0, 40/0. Test and standard solutions were prepared at a concentration of 1.0 mg/mL and 1.0 µg/mL, respectively, using a mixture of mobile phase A and acetonitrile (75/25) as diluent. This is the first specific, selective, sensitive, linear, precise, accurate, and robust HPLC method for the determination of Eltro-1A – Eltro‐1K in Eltro-1, which showed no significant degradation under thermal stress, photostability (UV and VIS), and standard accelerated and long-term stability conditions.

Trace level Determination of 2-(3-(trifluoromethyl)phenyl)propanal in Calcium Sensing Receptor drug by GCMS

The study aimed to develop and validate the method for trace level analysis of 2-(3-(trifluoromethyl)phenyl)propanal (2-TFL) impurity in calcium sensing receptor drugs by gas chromatographic method using mass spectrometry (GC-MS). The method utilizes a capillary column with 6% cyanopropyl phenyl and 94% dimethylpolysiloxane stationary phase with EI source in Selective Ion Monitoring (SIM) mode under programming temperature was used. After successful development, the method was validated according to our in-house validation guidelines for trace level analysis. The method proved to be selective for 2-(3-(trifluoromethyl) phenyl)propanal impurity in drug substance. A dissolve and injection approach was adopted for sample introduction in a split mode. Methanol was used as a diluent. The calibration curves showed good linearity over the concentration range from 1.85 (LOQ to 5.56ppm (150%)) of the target concentration of 3 ppm. The correlation coefficient obtained was >0.999. A limit of detection (LOD) of about 0.56ppm was achieved and limit of quantitation (LOQ) of 1.85ppm was achieved for 2-(3-(trifluoromethyl)phenyl)propanal impurity, when the samples were prepared at 20mg/mL. While recovery proved to be 101.0% at Limit of quantification (LOQ) level, 102.1% at Target analytical level (TAL) and 98.1% at 150% of the TAL, demonstrate the absence of matrix effect.

A specific chiral HPLC method for lifitegrast and determination of enantiomeric impurity in drug substance, ophthalmic product and stressed samples

Lifitegrast is a lymphocyte function-associated antigen-1 (LFA-1) antagonist used to treat the indications and symptoms associated with dry eye disease (DED), one of the most common ocular surface diseases. Lifitegrast has a chiral center, and the S-enantiomer (S-Lif) is responsible for the therapeutic effects, while the R-enantiomer (R-Lif) lacks efficacy in the treatment of DED. Lifitegrast ophthalmic solution containing 5% lifitegrast was approved by the United States Food and Drug Administration (FDA) in July 2016 for the treatment of DED in patients 17 years of age and older. The objective of this study was to develop a chiral HPLC method for the determination of the enantiomeric impurity of lifitegrast in the drug substance and in the ophthalmic product. In addition, we aimed to investigate the effect of stress and stability conditions on the enantiomeric purity of lifitegrast in both drug substance and ophthalmic solution. During the method development studies, four known lifitegrast impurities (Lif. Imp. A-D) and stressed lifitegrast samples were injected to ensure the specificity of the developed method. The enantiomers of lifitegrast are well separated with a resolution of higher than 4.0. They are also well separated from the peaks of the diluent, impurities, and the placebo used to prepare the ophthalmic solution without interference in 20 min. Chiral separation was achieved using a Chiralpak AD-H column (250 × 4.6 mm, 5.0 μm) at 40 °C with a mobile phase consisting of a mixture of n-hexane, 2-propanol, and formic acid (500:500:2, v/v/v) at a flow rate of 1.0 mL/min and a detection wavelength of 260 nm. Methanol was used as the diluent, and the drug substance solution was found to be stable for 48 h at 15 °C. The optimized chiral HPLC method for lifitegrast was validated according to ICH Q2, and the calibration curves showed excellent linearity for R-Lif (0.0369 – 1.816 µg/mL). This is the first stability-indicating, specific / selective, sensitive, linear, precise, accurate, and robust chiral HPLC method for the determination of R-Lif in S-Lif. The amount of enantiomeric impurity R-Lif in S-Lif increased under all stress and photostability test conditions without exceeding the acceptable impurity limit, with the most significant increase observed at elevated temperatures (105 °C) for both the drug substance in powder form and the ophthalmic drug solution.

A Quantitative Approach for the Determination of Elemental Impurities in Zinc Orotate Dihydrate Drug Substance by ICP-MS Method

These days elemental impurities are commonly present in active pharmaceutical ingredients, raw materials, during the synthesis of compounds, drug excipients, finished products, equipment, containers and closures. Inductively coupled plasma mass spectrometry (ICP-MS) is one of the advanced techniques to analyze elemental impurities in drug substances. An ICP-MS method was developed and validated for testing 17 elements, namely, V, Co, Ni, As, Se, Ru, Rh, Pd, Ag, Cd, Os, Ir, Pt, Au, Hg, Tl, and Pb in zinc orotate dihydrate. The samples were analyzed after diluting with concentrated nitric acid and concentrated hydrochloric acid. Li, Y, Tl, Co and Ce were assigned tuning solutions to correct the baseline drift and matrix interference. The RF power was 1550 W, RF matching was 1.80 V, sample depth was 8.0 mm, nebulizer gas flow was 1.01 L/min, nebulizer pump flow was 0.10 rps, spray chamber temperature 2oC, He flow rate was 4.3 mL/min and the energy discrimination rate was 3.0 V. All 17 elements exhibited excellent linearity in their testing range, with a coefficient of determination ≥ 0.9996. The limits of detection of the 17 elements were within the range of 0.0004 to 0.00411 ppm. The intra- and inter-day precision (relative standard deviation) was <6.4%. The recoveries of the spiked standard for all elements were 88.5 to 108.2%. Among the 17 elements of the zinc orotate dihydrate, the measured results of all the 17 elements were within the specified range, and the results of all the elements were also satisfactory. The developed method was simple, rapid, and effective. This method can be a powerful tool and imperative technology for the quantification of compounds in drug substances and pharmaceutical industries.

Nitrosamine Impurity: Management of Unwelcome Guest in Pharma Market

Nitrosamine impurities have been detected in various pharmaceutical products in recent days. Various sartans, ranitidine, nizatidine and metformin have been recalled from the markets due to the high limit of nitrosamine impurities. When assessing the danger of human cancer, pharmaceutical products ability to regulate potentially mutagenic and carcinogenic contaminants is crucial. The risk of their mutagenic and carcinogenic potential has increased with the recent finding of nitrosamine impurities in various commercially available medications. Nitrosamine is the substance deemed to be a potential human carcinogen by the International Agency for Research on Cancer (IARC). Impurities in nitrosamines have been shown to be mutagenic and carcinogenic; even very low exposure levels to these impurities can cause cancer. These impurities may be created by a reagent, catalyst, solvent, or raw materials employed in the manufacturing process and end up in drug substances or drug products. Angiotensin II receptor blocker (ARB) medications with nitrosamine impurities have caused widespread health problems. Risk management of nitrosamine impurity is necessary to control the level of this impurity in drug substance, drug product and APIs. By using risk management tools like fishbone diagram which is used to identify and organize the possible sources of nitrosamines in medicines. For detection of nitrosamine impurity different countries develops their own analytical methods.

A new stability-indicating HPLC-UV method for determination of amlodipine besylate and its impurities in drug substance

A new fast stability-indication high performance liquid chromatography method was developed and validated for the determination of amlodipine besylate and its organic impurities in drug substance. The separation of amlodipine and its seven impurities was achieved on a core shell C18 column, 100 mm × 4.6 mm; 2.6 μm, within 15 min. The mobile phase comprised of 0.4% ammonium hydroxide in water and methanol delivered in a gradient mode; the method detection wavelength is 237 nm. The selected column is stable at high pH and provided a good peak shape for basic compounds. Amlodipine besylate was subject to acid, base, oxidative, thermal, and photolytic stress conditions. The degradation products were well resolved from the amlodipine peak and its impurities. Major degradants were analyzed by liquid chromatography coupled with single-quadrupole mass detector. Amlodipine peak was shown to be free of co-elution by mass spectral analysis in all stress conditions. The method was validated in terms of specificity, linearity, accuracy, precision, and robustness. The developed method could be applied for routine quality control analysis of amlodipine besylate drug substance.

Development and Validation of a Simple and Sensitive ICP-MS Method for the Quantification of Elemental Impurities in Propafenone Hydrochloride Drug Substance

Elemental impurities are substances present in drug products, excipients, or drug formulations. They may be formed by the presence of catalysts and environmental contaminants. Elemental impurities can be detected by a sophisticated method such as Inductively Coupled Plasma Mass Spectrometry (ICP–MS). ICP-MS is an advanced method to detect elemental impurities in drug substances. In this study Propafenone hydrochloride drug was used, Propafenone Hydrochloride is an antiarrhythmic medication belonging to class 1C used to prevent supraventricular and ventricular arrhythmias. The present study was aimed to develop and validate inductively coupled plasma mass spectroscopic (ICP–MS) method for detection of elemental contaminants, i.e., Class 1, Cd, Pb, As, Class 2A, Hg, Co, V, and Class 2B impurities such as Ni, T1, Se, Ag, Au, Pd, Ir, Os, Rh, Ru, and Pt. Total 17 elemental impurities were detected in Propafenone Hydrochloride and this method was employed for the regular sample analysis of 17 elemental impurities in Propafenone Hydrochloride for pharmaceutical use. The instrument conditions were set using RF power of 1550 W, auxiliary gas of 0.5 L/min, and nebulizer flow of 1.01 L/min nebulizer pump pressure was 0.10 rps, spray chamber temperature was 2°C, and mode used was He, He flow rate was 4.3 mL/min and the energy discrimination rate was 3.0 V. The technique is sensitive and may identify desirable elemental impurities within permissible regulatory limits when additional elements are present. The proposed ICP-MS approach has been found to be accurate, precise, linear, rugged, robust, and convenient for the quality control of the drug substance propafenone hydrochloride. The linearity results for each impurity were 0.9990. The methods were validated according to USP requirements and International Council for Harmonization ICH guidelines. The suggested approach is an excellent quality control tool for the concurrent quantitative assessment and detection of elemental contaminants at low levels in the drug substance propafenone hydrochloride.

Implementation of green chemistry to develop HPLC/UV and HPTLC methods for the quality control of Fluconazole in presence of two official impurities in drug substance and pharmaceutical formulations

Two eco-friendly chromatographic methods were developed for analysis of Fluconazole (FLU) in presence of its official impurities B and C in drug substance and pharmaceutical formulations. For the HPTLC- densitometry, the separation was achieved using silica gel plates and mobile system consisting of ethyl acetate: water: acetic acid (8: 1: 1 v/v/v). The HPLC/UV was conducted on column C18 and a mixture of (water: ethanol) in gradient elution at flow rate 1.5 mL/min. The developed methods were validated according to ICH guidelines and they were able to determine FLU without interference from its two structurally related impurities with an accepted resolution and at low concentration level. The linearity was achieved over the range 50–500 μg/spot for HPTLC and 1-500 μg/mL for HPLC/UV. The LOD and LOQ values were 41.3 and 50 μg/spot for HPTLC and 0.052 and 0.15 μg/mL for HPLC/UV, respectively. The results were statistically compared to those obtained by reported methods showing no significant difference in terms of accuracy and precision. The green character of the developed methods was assessed and compared with reported methods using four different tools; NEMI, analytical eco-scale, GAPI and AGREE. The developed methods were found to be greener than the reported methods.

NDMA Formation Due to Active Ingredient Degradation and Nitrite Traces in Drug Product

N-nitrosamines are genotoxic compounds which can be found as impurities in drug substances and drug products used in the pharmaceutical industry. To date, several possible nitrosamine sources in drug products have been reported and this study aims to illuminate another one. A case of afatinib drug product was investigated, in which up to 50 ppb N-nitrosodimethylamine (NDMA) traces were detected. Afatinib was found to degrade to the secondary amine dimethylamine (DMA), forming NDMA with traces of nitrite in crospovidone. Two series of film-coated tablets were prepared with crospovidone from two different manufacturers, containing different levels of nitrites. Tablets were subjected to an accelerated stability study (40 °C/75% relative humidity) or stored at room temperature and levels of NDMA, DMA and nitrite in tablets were monitored. NDMA and nitrite were found on ppb levels, whereas DMA was detected on ppm levels. NDMA formation in the drug product was found to be time, temperature and nitrite dependent and it was emphasized that DMA and nitrite should be reduced. The accelerated stability study proved to be a useful tool for predicting nitrosamine formation in the drug product.

Impurity Purging through Systematic Process Development of a Continuous Two-Stage Crystallization

A methodical development approach was deployed in a novel portable manufacturing (Pharmacy on Demand) unit to purify ciprofloxacin hydrochloride hydrate within assay, water content, and impurity specifications described by the United States Pharmacopeia (USP) monograph and ICH Q3A(R2) guidelines for new impurities in drug substances. A series of design-of-experiment (DOE) and one-factor at a time (OFAT) experiments led to the optimization and control of a continuous two-stage crystallization that increased both the purity and yield of ciprofloxacin hydrochloride hydrate. Additionally, a statistically significant linear model was derived in batch within a 20 °C range that tracked the level of a difficult-to-purge impurity in stage 1 of the purification. This model was tested in continuous flow and predicted the impurity removal within 5% accuracy. With parametric control of process parameters, determined by optimization and modeling work, continuous flow isolations produced an active pharmaceutical ingredient (API) which had no individual impurities above 0.07%, with an isolated yield of 74%. In addition, acceptance criteria for assay (between 98 and 102%) and water content (between 4.7 and 6.7%) were met per the USP monograph for ciprofloxacin hydrochloride hydrate for the first time in the novel POD system.

A Detailed Review on Analytical Methods to Manage the Impurities in Drug Substances

A Detailed Review on Analytical Methods to Manage the Impurities in Drug Substances

Практичне застосування високоефективної рідинної хроматографії та високоефективної тонкошарової хроматографії у фармацевтичному аналізі.

The purpose of this work is to analyze the chronology and state of development of chromatographic methods at the Zaporizhzhia State Medical University (ZSMU). A historical overview of the use of chromatographic methods at ZSMU is provided. First of all, emphasis is placed on the introduction of high-performance liquid chromatography and gas-liquid chromatography. The main scientific laboratories and groups that worked and are working at the Zaporizhzhia State Medical University in the field of instrumental chromatography are shown. There were groups at the Department of Biological Chemistry, the Department of Faculty Pediatrics, the Department of Physical and Colloidal Chemistry. Currently, the Department of Physical Colloid Chemistry is actively working on a new laboratory of liquid chromato-mass spectrometry of the Department of Experimental Pharmaceutical Research of the training medical-laboratory center. The laboratory performs research for many departments of ZSMU, including the Faculty of Pharmacy, the Faculty of Postgraduate Education, the Faculty of Medicine. The laboratory develops, validates and uses methods to establish the purity and confirm the molecular weight and structure of new biologically active substances synthesized to search for new drugs, research of impurities in drug substances, determination of biologically active substances in extracts of medicinal plant raw materials, determination of residual amounts drugs in poultry meat and eggs, and other livestock and poultry products, determination of concentrations of disease markers, determination of distribution, metabolism and excretion of drugs.

Rapid identification of short oligonucleotide impurities using lithium adduct consolidated MALDI-TOF mass spectrometry

Nucleic acids are an increasingly popular platform for the development of pharmaceuticals to treat and prevent multiple diseases including those where traditional small molecule and protein-based drug development efforts have failed. Short oligonucleotide therapeutics, which consist of antisense oligonucleotides (ASOs) and short interfering ribonucleic acids (siRNAs), are prepared by solid phase chemical synthesis, which can generate various impuriies that have the potential to lower drug safety and efficacy. Drug substance-related impurities can be especially difficult to identify and characterize. To address this short coming, here we apply lithium adduct consolidation with matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) to afford a simplified, quick, and facile method for identification of a known drug substance impurity, isobutyryl (iBu) groups arising from incomplete deprotection during solid phase synthesis. We further employ high-resolution nuclear magnetic resonance (NMR) spectroscopy to confirm assessment of the iBu impurity. This lithium adduction consolidation method should find general applicability for routine quality assessment of synthetic oligonucleotides in both academic and industrial laboratories.

Risk Assessment of Genotoxic Impurities in Drug Substances

Risk Assessment of Genotoxic Impurities in Drug Substances

A substructure-based screening approach to uncover N-nitrosamines in drug substances.

Drug substances are at risk of contamination with N-nitrosamines (NAs), well-known carcinogenic agents, during synthesis processes and/or long-term storage. Therefore, in this study, we developed an efficient data-based screening approach to systemically assess marketed products and investigated its scalability for benefiting both regulatory agencies and pharmaceutical industries. A substructure-based screening method employing DataWarrior, an open-source software, was established to evaluate the risks of NA impurities in drug substances. Eight NA substructures containing susceptible amino sources for N-nitrosation have been identified as screening targets: dimethylamine (DMA), diethylamine, isopropylethylamine, diisopropylamine, N-methyl-2-pyrrolidone, dibutylamine, methylphenylamine, and tetrazoles. Our method detected 192 drug substances with a theoretical possibility of NA impurity, 141 of which had not been reported previously. In addition, the DMA moiety was significantly dominant among the eight NA substructures. The results were validated using data from the literature, and a high detection sensitivity of 0.944 was demonstrated. Furthermore, our approach has the advantage of scalability, owing to which 31 additional drugs with suspected NA-contaminated substructures were identified using the substructures of 1-methyl-4-piperazine in rifampin and 1-cyclopentyl-4-piperazine in rifapentine. In conclusion, the reported substructure-based approach provides an effective and scalable method for the screening and investigation of NA impurities in various pharmaceuticals and might be used as an ancillary technique in the field of pharmaceutical quality control for risk assessments of potential NA impurities.

Pharmaceutical analysis by NMR can accommodate strict impurity thresholds: The case of choline

The ICH guidelines recommend reporting thresholds for regular impurities in drug substances at the level of 0.05% or 0.03% (w/w) depending on the maximum daily intake. Therefore, any instrumental method of analysis applicable to the impurity analysis should be able to detect and quantify the analytes at those levels. This investigation was designed to verify the suitability of 1H NMR spectroscopy for the detection of impurities, as a first step in the process before attempting quantification. In order to minimize demand on equipment, this study employed a 400 MHz instrument for structural confirmation and signal assignments of choline (1) and O-(2-hydroxyethyl)choline (2), a known impurity. The limit of detection (LOD) of 2 in 10 mg of 1 was established as 0.01% on a 400 MHz instrument and 2% on a 60 MHz (benchtop) NMR spectrometer. Thus, impurities for which quantification is required are readily detected at 400 MHz or above. These results are in contrast to the widespread belief that 1H NMR sensitivity is insufficient for pharmaceutical impurity analysis. The choice of solvent was recognized as a critical parameter for 1H NMR LOD analysis. Furthermore, publicly available NMR raw data (HMDB) proved to be valuable for unveiling the otherwise cryptic information hidden in complex signal patterns via 1H NMR iterative Full Spin Analysis. Finally, the study uncovered the less noticed, yet characteristic, 14N–1H coupling in the -N+(CH3)3 groups, adding strong arguments for the Raw NMR Data Initiative. Collectively, the data prove that the analytical capabilities of high-field NMR easily fulfill the ICH requirements for detection of impurity in the presence of an actual substance of interest which makes it a step closer to achieving regulatory standards.

QUALITATIVE AND QUANTITATIVE ASSESSMENT OF RELATED SUBSTANCES IN THE CLOBETASOL PROPIONATE IN TOPICAL CREAM DOSAGE FORM BY RP-HPLC

The identification and control of impurities in drug substance and drug product is considered as very critical factor by regulatory agency for safe and effective use of Drug product for its intended use. A specific and sensitive Reverse Phase High Performance Liquid Chromatography (RP-HPLC) method is developed and validated for the estimation of 11 specified impurities in Topical Clobetasol Propionate Cream. The chromatographic parameters for develop method are C18 column, proportion of Water: Methanol: Acetonitrile: Trifluoro acetic acid as mobile phase at flow rate of 1.2 ml/min and UV detection at 241 nm. The method is validated for parameters as specified in ICH guideline. Developed method is validated for range 0.05–0.75 μg/mL for which Linearity, accuracy and precision was proven with acceptable limits. Method is sensitive as established Limit of Detection (LOD), and Limit of Quantitation (LOQ) are 0.02% and 0.06% respectively.

RP-HPLC Method Development and Validation for the Estimation of Lansoprazole in Presence of Related Substances by QbD Approach

A rapid specific RP-HPLC method has been developed for the determination of Lansoprazole impurities in the drug substance. The control of pharmaceutical impurities is currently a critical issue in the pharmaceutical industry. The International Council for Harmonization (ICH) has formulated a workable guideline regarding the control of impurities. The objective of the recent study was to develop and validate a HPLC method for the quantitative determination of process-related impurities of Lansoprazole in pharmaceutical drug substance. Lansoprazole, 2-[[[3-methyl-4-(2,2,2-trifluoroethoxy)-2-pyridinyl] methyl]-sulfinyl]- 1H-benzimidazole is an proton pump inhibitor used in the management of gastric ulcers. Chromatographic identification of the impurities was carried out by response surface methodology, applying a three-level Box Behnken design with three center points. Three factors selected were a mobile phase, flow rate, column temperature. Evaluation of the main factor, their interaction, and the quadric effect on peak resolution were done on Waters Symmetry C8, 250 x 4.6mm, 5µm column is used for the development of the method. The mobile phase consists of buffer and acetonitrile. The flow rate of the mobile phase was 1.0 ml/min with gradient elution. The column temperature is ambient and the detection wavelength is 235 nm. The injection volume was 10 µL. The method was validated as per ICH guidelines for linearity in the range of 50-150 µg/ml and the LOD & LOQ values obtained were 0.437×10-4 and 0.1325×10-3 µg/ml respectively which specifies the method's sensitivity. The proposed method was successfully used to determine the Lansoprazole impurities in drug substances.

Low-Level Determination of Mutagenic Nitrosamine Impurities in Drug Substances by LC–MS/MS

Since the detection of N-nitrosodimethylamine (NDMA) in a batch of valsartan in 2018, at levels exceeding ICH acceptable intake limits for mutagenic impurities, the analysis of nitrosamines has become an intense focus point for the pharmaceutical industry. The identification and low-level determination of nitrosamines in potentially affected materials is challenging and requires the application of highly sensitive analytical techniques. This article reviews the chronological development of the story and the regulatory landscape that has evolved. It will then discuss the development of analytical methods for the determination of a series of nitrosamines referenced by regulatory authorities, demonstrating separation of these compounds from the active pharmaceutical ingredient (API) and looking at how mass spectrometry (MS) can be applied to ensure that the required detection limits can be reached.