Photolytic Stress Conditions Research Articles

Separation and characterization of hydrolytic degradation product of deucravacitinib by validated high‐performance liquid chromatography method and liquid chromatography‐mass spectrometry

AbstractDeucravacitinib, SOTYKTU was approved recently in the year 2022 to treat psoriasis. The present work attempts to identify and characterize degradation products formed when the drug is exposed to hydrolytic, oxidative, thermal, and photolytic stress conditions as well as to study the kinetics of the drug's degradation under various stress conditions. A high‐performance liquid chromatography method was developed for the separation of deucravacitinib and its degradation product comprising mobile phase of ammonium acetate (pH 4.75) buffer as solvent A and acetonitrile as solvent B and Phenomenex Gemini, C‐18 (250 × 4.6 mm, 5µ) column as stationary phase. Injection volume, flow rate, and detection wavelength for the method were optimized as 10 µL, 1.0 mL/min, and 254 nm, respectively. Accuracy, precision, linearity, robustness, and selectivity were found to be acceptable when validated in the concentration range between 5 and 150 µg/mL of deucravacitinib. The structure of the degradation product was characterized using liquid chromatography‐tandem mass spectrometry which shows a protonated molecular ion peak at m/z 358.1805 in the electrospray ionization positive mode. In silico mutagenicity tests yielded positive results for deucravacitinib and its degradation product, triggering an alarm for mutagenicity for both structures, whereas in silico toxicity studies did not generate any structural alerts.

Stability-indicating UPLC assay coupled with mass spectrometry for the analysis of vilanterol degradation products in human urine

Vilanterol is a once-daily dose inhaler prescribed for asthma and chronic obstructive pulmonary disease. This study involved an investigation of vilanterol stability under acidic, basic, oxidative, thermal, and photolytic stress conditions. UPLC method was developed and validated for the analysis of vilanterol with its degradants. The drug was stable under photolytic and thermal stress conditions and degraded under acidic, basic, and oxidative stress conditions. Degradation kinetics was performed for acidic, basic and oxidative stress conditions. Kinetics parameters, K, half-life time (t1/2) and shelf-life time (t90) were assessed, and the degradation followed first order reaction. The method was linear from 0.10 to 100.00 µg mL−1 with accuracy, inter-day and intra-day precision from 99.45 to 100.02%, 0.391–0.694 and 0.041–0.345, respectively. Mass spectrometry was employed to elucidate the structure of the degradants, and the results revealed that certain degradation products were comparable to vilanterol metabolites. The World Anti-Doping Agency has prohibited the presence of vilanterol and its metabolites in athletes’ urine except for exercise bronchoconstriction with limited dose. So, quantification of vilanterol in the presence of its degradants was performed in human urine. The results revealed that the method was linear in range of 1.00 to 100.00 µg mL−1. Samples collection and experimental protocol was performed according to the guidelines of the Research Ethics Committee of the Faculty of Pharmacy, the British University in Egypt with approval No. CH-2305.

Development and validation of the RP-HPLC method for quantification of tavaborole.

The stability-indicating approach for tavaborole quantification was developed and validated to establish a precise, linear, accurate, and robust HPLC method. The development section includes optimizing the detection wavelength, the mobile phase ratio, and the type of column used to achieve the best possible separation and sensitivity for analysis. The chromatographic conditions were established, considering peak symmetry, resolution, and retention time. The mobile phase composition, comprising a buffer: acetonitrile (75 : 25, %v/v), with an injection volume of 15 μL, showed suitable elution and recovery at 265 nm. A constant column oven temperature of 35 °C and a 1 mL min-1 flow rate were maintained. The pH of the buffer was changed to 3.0 by using orthophosphoric acid. Linearity was observed from 5 to 1000 ppm (r2 = 1.00000). The capacity (retention) factor (k) of 3.43 was observed, indicating significant interaction and good separation. Forced degradation (FD) or stress tests were performed for chemical and physical photolytic stress conditions, and the results observed were within the specified limits. The stability in the analytical solution was observed for up to 35 hours at 5 °C, confirming the stability of the solution. Validation of the developed HPLC method confirmed the system's suitability, precision, linearity, accuracy, FD, robustness, and results. All validation criteria for the technique were within acceptable limits.

Stability-Indicating Liquid Chromatography Method for Rifaximin and LC-MS Characterization of its Potential Degradants

Rifaximin (RFX) is a structural analog of rifampin that has been shown to be a gastrointestinal-selective antibiotic with broad-spectrum antibacterial properties, a pronounced safety profile, and limited drug interactions. Crohn’s disease, diarrhea, hepatic encephalopathy, irritable bowel syndrome, and traveler’s diarrhea caused by non-invasive diarrheagenic Escherichia coli, can all be treated with rifaximin. FDA has designated RFX as an orphan drug for the treatment of hepatic encephalopathy. There is a substantial need for analytical quality monitoring of Rifaximin to ensure the safety and efficacy of treatment. To generate degradants, forced degradation study of the drug was carried out in acid, alkali, oxidative, thermal, and photolytic stress conditions. The optimum separation of the drug, and its degradants was achieved on an Inertsil ODS-3V C18 column (250 X 4.6 mm X 5 μm) under gradient elution conditions using, 10 mM potassium dihydrogen orthophosphate (pH 5.0 ± 0.05) as mobile phase A, and acetonitrile as mobile phase B, at a flow rate of 1.0 mL/min. The run time was 41 minutes and the detection wavelength was 258 nm. The method was validated in accordance with the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human use Guidelines. The drug was stable in neutral hydrolysis, photo and dry heat degradation conditions. The percentage degradation observed during acid, alkali hydrolysis and oxidative stress conditions were 70.46, 15.11 and 24.18, respectively. The degradants were investigated by LC-MS which indicated the presence of four (m/z 784.2, 744.5, 784.3, 753.8), three (m/z 744.5, 784.3, 753.8) and five (m/z 772.4, 838.4, 744.5, 753.8, and 801.9) degradants in acid, alkali and oxidative stress conditions, respectively. The structures of degradants were elucidated using Liquid chromatography–mass spectrometry (LC-MS) and Liquid chromatography tandem mass spectrometry (LC-MS/MS) analyses.

Size exclusion chromatography as green support for forced degradation study of adalimumab.

Size exclusion chromatography (SEC) has become a powerful tool for analysing size variants of biologic drugs in their native form. Modern SEC can be defined by the use of chromatographic columns packed with sub-3 µm particles, allowing an increase in method throughput compared to that of conventional SEC. We performed the forced degradation study of adalimumab, the first genetically engineered fully humanised immunoglobulin G1 monoclonal antibody, and evaluated tha possibilities of an advanced SEC column packed with sub-3 µm particles for elucidation of the degradation pathway. Our results revealed the main adalimumab degradation products to be antibody fragments. Acidic and basic conditions had the most intensive effect on the degradation of the adalimumab while the drug exhibits relative stability under thermal and photolytic stress conditions. The AGREE and AGREEprep calculators were used for the evaluation of the environmental performance of the forced degradation procedure. The results of the green score evaluation are presented as round pictograms with a circle in the centre that shows the overall score of 0.81 and 0.61, respectively. Both pictograms are highlighted in green, indicating the eco-friendly conditions.

Identification of degradation products of brivaracetam using liquid chromatography quadrupole time-of-flight tandem mass spectrometry: Degradation pathway elucidation.

Pyrrolidone-based drugs find widespread use in treating conditions such as epilepsy and Alzheimer's disease, and in various other medical applications. Brivaracetam, the latest generation of pyrrolidone drugs, has exhibited significant promise owing to chemical structure modifications. Its affinity to the SV2A receptor is double that of the previous-generation drug, levetiracetam. Consequently, brivaracetam holds substantial potential for diverse applications. As a novel drug not yet included in the pharmacopeias of developed nations, comprehensive analysis and research are necessary to guarantee its safe utilization in clinical settings. A liquid chromatography quadrupole time-of-flight tandem mass spectrometry (LC/QTOFMS) method has been developed to effectively separate, identify and characterize both the degradation products and process-related substances of brivaracetam. Stress testing of the sample was carried out following the guidelines outlined in ICH Q1A(R2). The structures of these impurities were identified through positive electrospray ionization QTOF high-resolution MS and NMR spectroscopy. Additionally, the formation mechanism of each degradation product is thoroughly discussed. Under the analytical conditions outlined in this paper, brivaracetam and its degradation products were effectively separated. Thirteen degradation products were detected and characterized, shedding light on their origins and degradation pathways. Among these, three degradation products align with previously reported impurities, and two unreported degradation products were synthesized and confirmed through NMR spectroscopy. The stress testing results revealed the instability of brivaracetam under acidic, alkaline, oxidative and thermal stress conditions, while it exhibited relative stability under photolytic stress conditions. The study developed an analytical method for brivaracetam that enabled the effective detection and separation of brivaracetam and its 13 degradation products. This method addresses a gap in both current domestic and foreign drug standards. The structures of all the major degradation products were characterized by high-resolution LC/QTOFMS, which is essential for quality control during the drug production process, stability evaluation and the establishment of proper storage conditions.

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.

A critical assessment on stability behaviour of Vorinostat using LC-MS-QTOF with H/D exchange and NMR

Vorinostat is the first USFDA-approved HDAC inhibitor for the treatment of cutaneous t-cell lymphoma. Vorinostat was exposed to ICH-recommended hydrolytic (acid, base, and neutral), oxidative, thermal, and photolytic stress conditions to understand the degradation behaviour. A Stability indicating LC method was developed and validated for separating and identifying forced degradation products. Under different stress conditions, six degradants were identified and characterized by LC-HRMS, MS/MS, and hydrogen-deuterium exchange mass studies. Vorinostat was found to be highly susceptible to the acidic and basic environment. In contrast, the drug substance was stable in the solid state under thermal and photolytic conditions whereas, it was found moderately stable when photolytic stress was provided to dissolved state of Vorinostat in acetonitrile-water. The degradants were identified as 7-amino-N-phenylheptanamide, 8-hydrazineyl-8-oxo-N-phenyloctanamide, 8-oxo-8-(phenylamino)octanoic acid, 8-oxo-8-(2-(7-oxo-7-(phenylamino)heptyl)hydrazineyl)-N-phenyloctanamide, 8,8′-(1-hydroxyhydrazine-1,2-diyl)bis(8-oxo-N-phenyloctanamide), and N1-((8-oxo-8-(phenylamino)octanoyl)oxy)-N8-phenyloctanediamide. The mechanistic explanation for the formation of each degradant in stability conditions has also been derived. The major degradants were also isolated/synthesized and characterized through 1H NMR for preparing impurity standards. Additionally, in-silico toxicity of the degradants was predicted in comparison to the drug, to identify whether any degradant has any specific type of toxicity and requires special focus to set specification limits during formulation development. The predicted toxicity indicated that the degradants have similar safety profile as that of the drug and specification can be set as per general impurity guideline.

Identification and characterization of the forced degradation products of lenvatinib mesylate by liquid chromatography-high resolution mass spectrometry

Lenvatinib mesylate (LEN) is a new generation anti-cancer medication included under the class of multiple kinase inhibitor and approved for the treatment of differentiated thyroid cancers that have not responded to the conventional radioactive iodine. It is marketed under the trade name Lenvima®. Forced degradation studies play an important part in the drug development process by providing crucial information about the inherent stability of the molecule under various conditions that are representative of the drug life cycle. The present study focused on exposing the active pharmaceutical ingredient, LEN to various stress conditions as per the ICH guidelines. LEN was found to degrade under hydrolytic stress whereas relatively stable in the thermal, oxidative and photolytic stress conditions. All the degradation products were separated on a Waters Acquity PFP (100 × 2.1 mm, 1.7 µm) column with mobile phase consisting of ammonium acetate in water and acetonitrile in gradient elution mode. LEN produced a total of nine degradation products (L1 to L9) which were structurally characterized with the help of LC-QTof-MS. The developed method was validated as per the ICH Q2 (R1) guidelines and was found to be specific, precise, accurate, linear and robust. The developed method can be effectively used for the routine batch analysis of LEN in bulk drug and various dosage forms in the presence of its degradation products /impurities.

Green quality by design HPLC approach for the simultaneous determination of Bilastine and Montelukast

For the simultaneous estimation of two co-formulated antihistaminic drugs (Bilastine and Montelukast), a novel and eco-friendly reversed-phase HPLC approach with both diode array and fluorescence detection modes was designed. Rather than using the routine methodology, the Quality by Design (QbD) approach was adopted to speed up the method development and to test robustness of the method. To evaluate the effect of variable factors on chromatographic response, a full factorial design was used. The chromatographic separation was performed using isocratic elution on the C18 column. The mobile phase consists of 92% methanol, 6% acetonitrile, and 2% phosphate buffer with 0.1 (v/v) triethylamine adjusted to pH 3, it was pumped at a flow rate of 0.8 mL/min with an injection volume of 20 μL. The developed stability indicating HPLC approach was used to assess the stability of montelukast (MNT). It was subjected to a variety of stress conditions, including hydrolytic (acid–base), oxidative, thermal, and photolytic stress conditions. All of these conditions were found to have relevant degradation pathways. Under the described experimental conditions, MNT degradation followed pseudo-first-order kinetics. The kinetic parameters of its degradation (rate constant and t1/2) were calculated and a proposal for the degradation pathway was postulated.

Stability Indicating HPTLC Method Development and Validation for Estimation of Nortriptyline and Pregabalin in Tablet Dosage Form

Chromatography is non-destructive procedure for resolving a multi-component mixture of solids, gases, Liquids. HPTLC is use of validated methods for qualitative and quantitative analysis. HPTLC is playing an important role in analytical world and a complementary method for HPLC. The analytical method was evaluated by using parameters such as Linearity, Precision, Accuracy, Limit of detection and Limit of quantification, Specificity, Robustness. In this method 100ng µL-1 and 750ng µL-1 volume of standard stock solutions of Nortriptyline and Pregabalin were taken, respectively. The mobile phase contains Toluene: Ethyl acetate: Methanol (6: 2: 1, v/v/v). Standard stock solutions were applied by over spotting on HPTLC plate with the help of CAMAG 100µl sample syringe, Linomat 5 sample applicator. The development chamber was saturated for 15 min. The plate was scanned at 210nm. The retention factors of PREGA and NORT were found to be PREGA: 0.48±0.03, NORT: 0.70±0.07. The % drug content (mean±S.D.) were found to be 99.32±1.39 for NORT and 99.75±1.15 for PREGA. The results of stress degradation studies revealed that NORT was prone to hydrolysis, oxidative, thermal and photolytic degradation whereas PREGA was found susceptible to hydrolysis, oxidative, thermal degradation but stable under photolytic stress conditions.

LC-MS-Compatible Chromatographic Method for Quantification of Potential Organic Impurities of Elagolix Sodium in Tablet Dosage Form with Identification of Major Degradation Products.

Elagolix is a gonadotropin-releasing hormone (GnRH) modulator and used for pain relief from endometriosis. The present research was performed to develop and validate a simple, novel, fast, sensitive, and cost-effective LC-MS-compatible chromatographic method for quantification of all prominent organic impurities of elagolix sodium in tablet formulation with identification of major degradation products. The optimum separation of the organic impurities of elagolix sodium was achieved on an ACE C18-PFP (250 mm × 4.6 mm, 5 µm) column by employing pH 5.6 acetate buffer-acetonitrile (95 + 5, by volume) as mobile phase A, and acetonitrile-methanol (90 + 10, by volume) as mobile phase B. UV detection of the drug and impurities was carried out at 210 nm. A forced degradation study was carried out by employing acid, alkali, oxidative, thermal, and photolytic stress conditions on elagolix sodium drug substance and its drug product. The major degradation products observed during the stress study were identified by using mass spectrometry. Elagolix sodium and its prominent organic impurities were resolved in the developed method through a gradient elution program of 46 min at a flow rate of 1.3 mL/min. Significant degradation was observed during alkali hydrolysis and oxidative stress conditions with a mass balance of more than 97.0%. The method was validated in line with present International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) Q2(R1) guidelines. The forced degradation study suggested that the developed method is specific and stability-indicating and can be used for related substance analysis of elagolix drug substance and its dosage forms. This is the first research paper which describes a simple and sensitive (LOD 0.08 µg/mL) HPLC method for quantification of all probable impurities of elagolix in tablet dosage forms. The noticeable feature of the developed method is resolution of impurities of similar structures in a short time using routine solvents which are easily available in the QC laboratory.

STABILITY INDICATING RP-HPLC PDA ANALYTICAL METHOD DEVELOPMENT AND VALIDATION FOR THE ESTIMATION OF BESIFLOXACIN HYDROCHLORIDE IN BULK AND FORMULATION

The goal of the study was to provide an overview of the technique development and validation of a stability-indicating HPLC approach for routine analysis of besifloxacin hydrochloride in pharmaceutical product (ophthalmic suspension). HPLC method was development on octadecasilyl silica (C18, 250 mm x 4.6 mm x 5µ) column at 37 °C and isocratic mode with a running solvent (phosphate buffer: methyl alcohol 40:60 % V/V) using flow rate (1.0 mL minute-1) and UV wavelength 292 nm. Proposed method was validated for specificity, linearity, accuracy, precision, range and robustness according to ICH Q2 (R1) standards. The collected results attest to the validated method’s compliance with the set acceptance standards. Besifloxacin hydrochloride was subjected to hydrolytic, oxidative, thermal and photolytic stress conditions. These samples were then examined using our suggested approach. Hence, this method can be used for routine use for determination assay of besifloxacin hydrochloride drug substance (API) and drug product (ophthalmic suspension).

Mechanism of capmatinib degradation in stress conditions including degradation product characterization using ultra-high-performance liquid chromatography-quadrupole-time of flight mass spectrometry and stability-indicating analytical method development.

Capmatinib (CMT) has been recently approved for the treatment of non-small cell lung cancer by the United States Food and Drug Administration (USFDA). Till date, the degradation mechanism of CMT in different stress conditions is not known. Moreover, degradation products (DPs) of the drug are yet to be identified. Characterization study on degradation products of CMT has not been reported before. Furthermore, no previously reported literature is available on the stability-indicating method of CMT. Owing to the lack of such scientific reports, we developed a sensitive, stability-indicating method for CMT which can resolve it from all its degradation products. The method was validated as per the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH Q2 [R1]) guideline. We studied and established the degradation mechanism of CMT in different stress conditions. One degradation product (DP2) was isolated and characterized using 1 H NMR. The degradation products (DP1, DP2 and DP3) of the drug have been identified and characterized for the first time by using high-resolution mass spectrometry and 1 H NMR spectroscopy. CMT was found to become degraded under acidic, basic and photolytic stress conditions in the solution phase to yield three major DPs. The drug was found to be stable in neutral hydrolysis, oxidation and thermal stress conditions. DP1 was formed under acidic and basic hydrolytic conditions, whereas DP2 and DP3 were formed under photolytic conditions. Characterization of all the DPs has been carried out to establish their structures and understand the molecular mechanism behind the degradation of the drug. Few studies reported quantitative analysis of CMT and its metabolites in biological fluids. However, this is the first study to identify the unknown DPs of CMT and the mechanism of its degradation. Moreover, this article reports a stability-indicating analytical method for CMT which has not yet been reported in any literature.

Development and validation of stability-indicating -HPLC method for the determination of related substances in novel nitroimidazole antituberculosis drug pretomanid: Robustness study by Design-Expert and application to stability studies.

This study developed a stability-indicating reversed-phase-HPLC method for the determination of related substances of the novel antituberculosis drug pretomanid. Critical quality attributes were evaluated and established for the robust method conditions by using quality-by-design based design of experiments. Forced degradation studies were carried out under acidic, basic, thermal, oxidative, and photolytic stress conditions. Pretomanid degraded when treated under basic conditions, whereas no significant degradation was observed under other stress conditions. The impurities were separated using a Bakerbond C18 column (150 × 4.6mm, 3μm) with the mobile phases 0.1% of orthophosphoric acid and acetonitrile in a time gradient mode. The HPLC method was validated according to the ICH (International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use) tripartite guidelines. Limit of detection and limit of quantitation of pretomanid and all its impurities were 0.1 and 0.4μg/mL, respectively. The method was found to be linear with a correlation coefficient >0.99, precision (% relative standard deviation < 5.0), robustness, and accuracy (% recovery: 85-115%). Stability studies were evaluated according to the ICH-Q1A, and the drug was were found to be stable in all storage conditions.

A Greener Stability-Indicating High-Performance Thin-Layer Chromatography Approach for the Estimation of Topiramate.

Despite various reported analytical methods for topiramate (TPM) analysis, greener analytical approaches are scarce in literature. As a consequence, the objective of the current research is to design a normal-phase stability-indicating high-performance thin-layer chromatography (SI-HPTLC) methodology for TPM analysis in marketed tablet dosage forms that is rapid, sensitive, and greener. TPM was derivatized densitometrically and analyzed at 423 nm in visible mode with anisaldehyde-sulfuric acid as the derivatizing agent. The greener SI-HPTLC technique was linear in the 30–1200 ng band−1 range. In addition, the suggested SI-HPTLC methodology for TPM analysis was simple, rapid, cheaper, precise, robust, sensitive, and environmentally friendly. The greener SI-HPTLC method was able to detect TPM along with its degradation products under acid, base, and oxidative degradation conditions. However, no TPM degradation was recorded under thermal and photolytic stress conditions. TPM contents in commercial tablet dosage forms were recorded as 99.14%. Using 12 different principles of green analytical chemistry, the overall analytical GREEnness (AGREE) score for the greener SI-HPTLC method was calculated to be 0.76, confirming the proposed normal-phase SI-HPTLC method’s good greener nature. Overall, these results demonstrated that the suggested SI-HPTLC technique for TPM measurement in pharmaceutical products was reliable and selective.

HPLC-PDA identification and resolution of rufinamide forced degradation impurities: A congregated chemometric expedite optimization coupled with factorials and desirability.

Rufinamide is used presently to treat Lenaux-Gastaut syndrome. A full factorial design and desirability approach was investigated for the optimization of hydrolytic stress via response surface curves (RSCs). The degradation impurities were identified and resolved using reversed-phase high-performance liquid chromatography (RP-HPLC) on the Qualisil® BDS C8 column. Acetonitrile-water (29:71, v/v) was optimized for the mobile phase and used at a flow rate of 1.0ml/min with detection at a wavelength of 230 nm. Rufinamide showed appreciable susceptibility to hydrolysis under acidic and alkaline stress, and substantial degradation in the neutral condition. It degraded much less under oxidative stress. Exposure towards thermal and photolytic stress conditions indicated appreciable stability. The developed method was subjected to validation as per the recommendations of the International Conference on Harmonization. The proposed method showed no influence from the excipients and the degradation products. As well as good precision and accuracy in determination, the method showed a linear response between 2 and 12 μg ml-1 . The method was extended for determination in a human plasma sample, which resulted in excellent recovery without interference from matrix effects. The combined use of desirability and design for the optimization of acidic and alkaline hydrolytic stress led to simple and rapid analysis.

A stability indicating method development and validation of esomeprazole in pharmaceutical dosage form by using RP-HPLC and In Vitro evaluation of nasogastric tube delivery of esomeprazole magnesium delayed-release capsules

A simple, selective and well-defined stability indicating method was developed for the quantitative estimation of esomeprazole in tablet dosage form using XBridge BEH Shield RP18 (4.6 x 250 mm), 5μm with phosphate buffer pH 7.3 and acetonitrile (740:260 %v/v) as a mobile phase and successfully validated as per the ICH guideline. The method was found to be specific, linear, accurate, rugged, and robust. Stress degradation studies were performed by exposing the esomeprazole magnesium delayed release capsules into acidic, alkaline, oxidative, thermal, humidity and photolytic stress conditions as per ICH guidelines. In separate in-vitro experiments, esomeprazole pallets dispersion passed through feeding tubes using gentle syringe pressure to develop a clog-free dispersion-delivery method. Nasogastric tube (8-French [Fr]) and diluents (different pH of water used i.e. pH 5.5, 7.0 and 8.5) were tested. The results showed excellent delivery of esomeprazole pellets using water as a medium for tube delivery. Recovery of esomeprazole pallets dispersion in different pH of water i.e. pH 5.5, 7.0 and 8.5 at “0 and 15” minutes incubation time were nearly 100% in 8-Fr nasogastric tubes. Keywords: Esomeprazole, Stress degradation, Stability indicating assay method, Nasogastric Tube.

A stability indicating method development and validation of apixaban in pharmaceutical dosage form by using RP-HPLC and In-Vitro evaluation of apixaban suspension delivery through enteral feeding tubes

A simple, consistent and sensitive stability indicating reversed phase high performance liquid chromatography (RP-HPLC) method was developed for the determination of Apixaban in pharmaceutical dosage form by using Zorbax C18 (150 mm x 4.6 mm, 5μm particle size) with a mobile phase consisting of Ammonium Formate Buffer: Acetonitrile in a ratio of 65:35% v/v and successfully validated as per the international council for harmonization (ICH) guideline. The method was found to be simple, robust, precise, sensitive, accurate; specific and stress degradation studies were performed with acidic, alkaline, oxidative, thermal, humidity and photolytic stress conditions as per ICH guidelines. In separate in-vitro experiments, Apixaban suspension passed through feeding tubes to develop a clog-free suspension delivery method. Nasogastric tube (8-French [Fr]) and diluents (water, 5% dextrose in water) were tested. Recovery of Apixaban Suspension in water and 5% dextrose in water at “0 and 15” minutes incubation time were nearly 100% in 8-Fr nasogastric (NG) tubes. Keywords: Apixaban, Stress Degradation, Stability Indicating Assay Method, Nasogastric Tube.

Identification and characterization of urapidil stress degradation products by LC-Q-TOF-MS and NMR: Toxicity prediction of degradation products

Urapidil, an antihypertensive drug is subjected to various stress conditions (acidic, basic, neutral, oxidative and photolytic) as per ICH guidelines. A stability indicating HPLC method was developed using InertSustain C8 (250 × 4.6 mm; 5 µm) column and 10 mM ammonium formate (pH 3.5) with gradient elution at a flow rate of 1 mL/min to separate all the DPs. The drug was susceptible to acidic and basic hydrolysis, oxidative and photolytic stress conditions in the solution phase and stable in neutral solution phase and photolytic solid state conditions. A total of five DPs were detected under different stress conditions including DP4 which was previously reported in the literature. An extensive fragmentation pattern of drug and DPs were established using LC-Q-TOF-MS which aided the characterization of DPs. The ambiguity in the position of N-oxide formation in DP5 was confirmed by NMR studies. In silico toxicity of the drug and its DPs were also evaluated. The plausible mechanism of DPs formation was explained.