Development and validation of a stability-indicating HPLC method for assay of tonabersat in pharmaceutical formulations.

A stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed to assay tonabersat and assess its stability in pharmaceutical formulations. Chromatographic separation was achieved using a Kinetex® C18 column (2.6 µm, 150 x 3 mm, 100 Å) at 50 °C, with a 20 µL injection volume. A linear gradient of acetonitrile in water (5 - 33.5 %) was applied for 1 min, followed by a gradual increase to 100 % over 26 min at a flow rate of 0.5 mL/min. Tonabersat and its degradation products were detected at 275 nm and 210 nm, respectively. The optimized method was used to evaluate the stability of tonabersat in lipid-based pharmaceutical formulations at 5 ± 3 °C, 25 ± 2°C/60 ± 5 % RH, and 40 ± 2 °C/75 ± 5 % RH over 3 months. The method was validated as per ICH guidelines and demonstrated linearity in the range of 5 - 200 µg/mL (R2 = 0.99994) with good accuracy (98.25 - 101.58 % recovery) and precision (% RSD < 2.5 %). The limits of detection and quantitation were 0.8 µg/mL and 5 µg/mL, respectively. Forced degradation studies showed significant degradation on exposure to alkaline (90.33 ± 0.80 %), acidic (70.60 ± 1.57 %), and oxidative stress (33.95 ± 0.69 %) at 70 °C, but no degradation was observed on exposure to thermal or photolytic stress. No chemical degradation was observed in either formulation on storage. Thus, the method was sensitive, specific, and suitable for stability testing of tonabersat in pharmaceutical formulations.

Separation and simultaneous estimation of enantiomers and Diastereomers of muscarinic receptor antagonist Solifenacin using stability-indicating Normal-phase HPLC technique with chiral stationary phase amylose tris-(3,5-dimethylphenylcarbamate).

The R,S-enantiomer impurity and diastereomer impurities (S,S-isomer and R,R-isomer) of the solifenacin (S,R-enantiomer) were effectively separated and quantified simultaneously utilizing normal-phase high-performance liquid chromatography with a chiral stationary phase consisting of amylose tris (3,5-dimethylphenylcarbamate) coated on silica-gel (Chiralpak, AD-H). The enantiomeric and stereo-selective separation was achieved within a run time of 35 minutes using a mobile phase of 'n-hexane, ethanol, and diethylamine' in an isocratic elution mode with a detection wavelength of 220 nm. The validation attributes assessed were accuracy (which showed excellent recoveries between 97.5% and 100.4%) and linearity (which was proven in the range of 0.081-1.275 µg.mL-1 , with a linear regression of 0.999). The stress testing experiments proved that the developed methodology by the HPLC technique has stability-indicating characteristics, as all closely eluting peak pairs were separated well with a resolution of 2.3 and without any interference. The proposed methodology was highly efficient in separating and simultaneously determining the chiral impurities (enantiomers and diastereomers) of the solifenacin in the release and stability sample analyses of drug substances and tablets in pharmaceutical formulations.

Differential role of potential stressors, underlying degradation mechanism, characterization of degradants using LC-MS/MS, and establishment of a stability-indicating analytical method for duvelisib.

Duvelisib (DUV) was first approved globally in 2018. An extensive literature search revealed that the differential role of a potential degradation medium in altering the shelf-life of DUV due to its exposure during storage has not been identified till date. Moreover, its degradation impurities and degradation mechanism are not known. In addition, no analytical method has been reported for the quantification of DUV in the presence of its degradation impurities. Therefore, the aim of this study was to identify the impact of different potential degradation media on the stability of DUV, establish the degradation mechanism, and identify its major degradation impurities. The aim was also to establish a stability-indicating analytical method for the quantification of DUV in the presence of its degradation impurities. This study is the first to report the structure of degradation impurities and the step-by-step degradation mechanism of DUV. This information will be useful for the scientific community and manufacturers in optimizing the formulation parameters and/or storage conditions. The validated method can be employed for analysis of stability study and routine quality control samples of newer DUV formulations in pharmaceutical industries. The identified impurities may serve as impurity standards for specifying their limits in the drug after required qualification studies.

Development of a novel quality by design-enabled stability-indicating HPLC method and its validation for the quantification of nirmatrelvir in bulk and pharmaceutical dosage forms.

A systematic and novel quality by design-enabled, rapid, simple, and economic stability-indicating HPLC method for quantifying nirmatrelvir (NMT) was successfully developed and validated. An analytical target profile (ATP) was established, and critical analytical attributes (CAAs) were allocated to meet the ATP requirements. The method used chromatographic separation using a Purosphere column with a 4.6 mm inner diameter × 250 mm (2.5 µm). The analysis occurred at 50°C with a flow rate of 1.2 mL/min and detection at 220 nm. A 10 µL sample was injected, and the mobile phase consisted of two components: mobile phase A, containing 0.1% formic acid in water (20%), and mobile phase B, containing 0.1% formic acid in acetonitrile (80%). The diluent was prepared by mixing acetonitrile and water at a 90:10 v/v ratio. The retention time for the analyte was determined to be 2.78 min. Accuracy exceeded 99%, and the correlation coefficient was greater than 0.999. The validated HPLC method was characterized as precise, accurate, and robust. Significantly, NMT was found to be susceptible to alkaline, acidic, and peroxide conditions during forced degradation testing. The stability-indicating method developed effectively separated the degradation products formed during stress testing, underlining its effectiveness in stability testing and offering accuracy, reliability, and sensitivity in determining NMT.

Delineation of prototypical degradation mechanism, characterization of unknown degradation impurities by liquid chromatography-quadrupole-time-of-flight-tandem mass spectrometry and stability-indicating analytical method of selumetinib.

Selumetinib (SELU) was recently approved by the US Food and Drug Administration (US FDA) in 2020. However, the degradation impurities of SELU have not been characterized or identified to date. The mechanism for impurity formation and the degradation behavior have not been previously studied. This study aims to elucidate the prototypical degradation mechanism of SELU. Furthermore, the degradation impurities have been identified using LC-quadrupole-time-of-flight tandem mass spectrometry and are reported in this article for the first time. In addition, a stability-indicating analytical method (SIAM) has been developed for this drug. Forced degradation studies revealed the degradation of SELU under various stress conditions, including hydrolytic stress (acid and base), oxidative stress, and photolytic stress (ultraviolet and visible). Three degradation impurities were identified. This article presents the first validated SIAM, capable of accurately quantifying SELU in the presence of its degradation impurities. Furthermore, we have proposed the degradation pathway for SELU and its degradation impurities, a first in the field. The developed SIAM can find applications in process development and quality assurance of SELU in both research laboratories and pharmaceutical industries. Moreover, the identified degradation impurities may serve as impurity standards for quality control testing in pharmaceutical industries.

Development, evaluation of critical method variables and stability assessment using a Box-Behnken design for the determination of organic impurities in a pharmaceutical dosage form of a centrally acting muscle relaxant drug chlorzoxazone.

This study validates a stability-indicating LC method for detecting organic impurities in the chlorzoxazone dosage form. Using a Waters X-Select R HSS T3 analytical column, mobile phase of it was made by mixing of water, methanol, and glacial acetic acid in the ratio of 700:300:10 (v/v/v). The drug product and drug substance were subjected to the stress conditions such as acid, base, oxidation, heat, and photolysis as per the recommendations of the International Conference on Harmonization (Q2) methodology. The study revealed the susceptibility of 4-chloro-2-aminophenol to alkaline environments, emphasizing peak homogeneity and stability. The method verification, per ICH guidelines and USP<1225>, established precision, specificity, linearity, accuracy, and robustness for quality control. The mean impurity recovery ranged from 95.5% to 105.2%, the correlation coefficient (r) was greater than 1.000, and the RSD values (n = 6) ranged from 0.6% to 5.1% across the LOQ-150% ranges. Full-factorial design tested final method conditions, evaluating multiple parameters concurrently. Graphical optimization within the design space defined strong method requirements, ensuring consistent and reliable outcomes. The study develops and validates chlorzoxazone stability-indicating methods, employing advanced statistical approaches like design of experiments and factorial design, with resilient conditions established through graphical optimization of the design space.

AQbD-guided development and validation of an innovative extraction procedure and stability-indicating RP-HPLC method for quantification of posaconazole in tablet formulation.

OBJECTIVE: The objective of this work is to develop a stability-indicating HPLC method for the quantification of posaconazole (PCZ) in tablet formulation using an Analytical Quality by Design (AQbD) approach. MATERIALS AND METHODS: The development process involved the Design of Experiments (DOE) utilizing distinctive constraints mixture design for mobile phase ratio optimization and a 2-level factorial design for selection of extraction diluent compositions. Key responses measured included % assay and system suitability parameters. Method operable design regions (MODR) were determined, and final optimum conditions were selected. Forced degradation studies were conducted to assess method stability. RESULTS: The optimized HPLC method employed a Zorbax C18 column with a mobile phase consisting of pH 3.5 10mM phosphate buffer, acetonitrile, and methanol in a ratio of 30:53:17% v/v/v. The method demonstrated stability-indicating capabilities, with PCZ degradation observed in acidic and oxidative environments, while remaining stable in alkali. Peak purity analysis from Empower software confirmed the absence of interaction with degradants. Validation according to ICH Q2 (R2) guidelines showed precision, linearity over the range of 0.25 to 376µg/mL, and accuracy demonstrated through recovery studies from 50 to 150%. CONCLUSION: The developed HPLC method utilizing AQbD approach is specific, robust, precise, and accurate for the quantification of PCZ in tablet formulations, thus suitable for routine analysis.

Advanced stability-indicating RP-HPLC method for the quantification of Lurasidone Hydrochloride in bulk and PLGA based in-situ implant formulation.

OBJECTIVES: The aims of the present investigation was to develop and validate stability-indicating RP-HPLC method for the estimation of Lurasidone hydrochloride (LURA-H) followed by its drug product, LURA-H encapsulated poly-D,L lactic-glycolic acid (PLGA) based in-situ depot forming implant (LURA-H-PLGA-ISI). METHODS: The LURA-H-PLGA-ISI formulation was developed by simple mixing method. According to international conference on harmonization guidelines, RP-HPLC method was developed and validated using Waters 2695 and discovery C18, 5µ, 250×4.6 mm ID column. Force degradation studied were performed by various degradation techniques. RESULTS: The chromatographic separations of LURA-H as well as LURA-H-PLGA-ISI with good resolutions have been achieved using the mobile phase 0.1% orthophosphoric acid and acetonitrile (50:50). The linearity in the range of 25-150 µg/mL of developed method. LOD and LOQ limits for LURA-H were found to be 0.07µg/mL and 0.22 µg/mL, respectively. The % RSD was found to be <2% showing the precision of developed method. The accuracy of developed method was demonstrated which is close to 100±2%. Little modifications in the chromatographic conditions indicated robustness of the developed method. Further, solution stability of LURA-H and LURA-H-PLGA-ISI was stable at room temperature. Furthermore, force degradation studies demonstrated LURA-H was unaffected and stable under thermal, photodegradation and neutral (hydrolytic) stress conditions. AGREE and GAPI assessment demonstrated the developed method is environmentally sustainable. CONCLUSION: The developed method is simple, robust, precise, accurate and sensitive which can be utilized for the regular analysis of LURA-H in quality control laboratories of bulk drug substance and PLGA containing formulations of LURA-H.

Stability Indicating RP-HPLC-DAD method for simultaneous estimation of tadalafil and macitentan in synthetic mixture for treatment of pulmonary arterial hypertension.

OBJECTIVE: High Performance liquid chromatography is an integral analytical tool in assessing drug product stability. A simple, selective, precise, accurate and stability indicating RP-HPLC method was developed and validated for analysis of Tadalafil and Macitentan in synthetic mixture. MATERIAL AND METHOD: Chromatographic separation was performed using Phenomex Gemini C18 (25cm×4.6nm, 5µm) Column. The mobile phase consists of (10mM Ammonium Acetate in water and [Methanol: ACN 20: 80% v/v]) (40: 60% v/v). The flow rate was set to be 1.0mL/min. The injection volume was 10.00µL. The detection was carried out at 260nm at column temperature 35°C. RESULTS: The method was validating according to ICH Q2R1 guideline for accuracy, precision, reproducibility, specificity, robustness and detection and quantification limits. Stability testing was performed on Tadalafil and Macitentan and it was found that these degraded sufficiently in all applied chemical and physical conditions. Linearity for Tadalafil and Macitentan was observed 0.4-100µg/mL and 0.1-25µg/mL with correlation coefficient at 0.9999. LOD and LOQ 0.008µg/mL and 0.024µg/mL and 0.001µg/mL and 0.0029µg/mL for Tadalafil and Macitentan respectively. CONCLUSION: The developed RP-HPLC method was found to be suitable for the determination of both the drugs.

Development and validation of stability indicating RP-HPLC method for simultaneous estimation of silodosin and mirabegron in synthetic mixture.

The study focuses to validate and develop a precise, simple and accurate stability indicating RP-HPLC method for estimation simultaneously of and silodosin and mirabegron in synthetic mixture. The chromatographic separation was achieved by using Shimpack Solar C18 column (250×4.5mm, 5µm) with acetonitrile: 5mM ammonium acetate in ratio of 90:10% v/v as a mobile phase at a constant flow rate of about 1.2mL/min. The development and validation were carried out at detection wavelength of 229nm. We developed a robust RP-HPLC method, validated for linearity, precision, accuracy, specificity, and system suitability. The method demonstrated excellent linearity with correlation coefficient value r2 was nearly 0.998 with linearity range 8-18µg/mL for Silodosin and 24-54µg/mL for mirabegron. LOD and LOQ were found to be lower; hence, the method is sensitive. Percentage recovery was obtained 99.97% and 99.99% for silodosin and mirabegron, respectively. In case of precision, robustness and repeatability, RSD was found to be less than 2. The validated and developed RP-HPLC method offers an efficient and practical approach for the simultaneous quantification of silodosin and mirabegron in pharmaceutical formulations, making it a valuable tool for quality control and pharmaceutical research.

Separation and quantitative estimation of stereo-selective enantiomers of montelukast in pharmaceutical drug substance and tablets dosage forms by using stability-indicating normal phase-HPLC method.

Montelukast sodium (MLS) is a leukotriene receptor antagonist that relieves asthma, bronchospasm, allergic rhinitis, and urticaria. A simple, robust, and stability-indicating normal phase high-performance liquid chromatography method was developed to separate and quantitatively estimate the S-enantiomer of MLS. The chiral separation was achieved using USP L51 packing material along with a mobile phase consisting of a solvent mixture (n-hexane, ethanol, and propionic acid), a flow rate of 1.0 mL/min, a detection wavelength of 284 nm, a column temperature of 30°C and an injection volume of 20 µL. The enantiomers peaks were well separated from the peaks of the placebo, diluting solvent, MLS, and its known impurities with a resolution of more than 2.2 and with no interference. Accuracy and linearity were studied in a range of 0.36-3.597 µg/mL (0.03%-0.30%), with good recoveries between 92.5% and 96.8% and a linear regression coefficient above 0.996. The suggested chiral chromatography method is being considered as an alternative and equivalent method to the United States Pharmacopeia and European Pharmacopeia monographs. The developed method was effectively employed for the study of release and stability samples of MLS. This HPLC method is also capable of separating and estimating the stereo-selective isomers (R- and S-enantiomers) of sulfoxide impurity of MLS in pharmaceutical medicine.

Development, stability-indicating assessment, and evaluation of influential method conditions using a full factorial design for the determination of Nintedanib esylate-related impurities.

The design of an appropriate analytical method for assessing the quality of pharmaceuticals requires a deep understanding of science, and risk evaluation approaches are appreciated. The current study discusses how a related substance method was developed for Nintedanib esylate. The best possible separation between the critical peak pairs was achieved using an X-Select charged surface hybrid Phenyl Hexyl (150 × 4.6) mm, 3.5 µm column. A mixture of water, acetonitrile, and methanol in mobile phase-A (70:20:10) and mobile phase-B (20:70:10), with 0.1% trifluoroacetic acid and 0.05% formic acid in both eluents. The set flow rate, wavelength, and injection volumes were 1.0 ml/min, 285 nm, and 5 µl, respectively, with gradient elution. The method conditions were validated as per regulatory requirements and United States Pharmacopeia general chapter < 1225 >. The correlation coefficient for all impurities from the linearity experiment was found to be > 0.999. The % relative standard deviation from the precision experiments ranged from 0.4 to 3.6. The mean %recovery from the accuracy study ranged from 92.5 to 106.5. Demonstrated the power of the stability-indicating method through degradation studies; the active drug component is more vulnerable to oxidation than other conditions. Final method conditions were further evaluated using a full-factorial design. The robust method conditions were identified using the graphical optimization from the design space.

White analytical chemistry-driven stability-indicating concomitant chromatographic estimation of thiocolchicoside and aceclofenac using response surface analysis and red, green, and blue model.

White analytical chemistry is a novel concept for the assessment of analytical methods on basis of its validation efficiency, greenness power, and economical efficiency. White analytical chemistry-driven stability indicating chromatographic method has been developed for the concomitant analysis of thiocolchicoside and aceclofenac. The proposed chromatographic method has been developed using a safe and environmental-friendly organic solvents for the concomitant stability study of thiocolchicoside and aceclofenac. The analytical risk assessment was carried out for the identification of high-risk analytical risk factors and analytical method performance attributes. The mixture design was applied for the design of experiments-based response surface modeling of high-risk analytical risk factors and analytical method performance attributes. The degradation products were isolated and characterized using infrared, nuclear magnetic resonance, and mass spectral data. The proposed method was compared for its validation efficiency, greenness power, and cost-efficiency with published chromatographic methods using the red, green, and blue models. The white score of the proposed and reported method was calculated by averaging the red, green, and blue scores of the methods. The proposed method was found to be robust, green, and economical for the concomitant stability study of thiocolchicoside and aceclofenac.

Determination of ivacaftor by liquid chromatography techniques in pharmaceutical formulation with interlaboratory comparison and characterization of five novel degradation products by high-performance liquid chromatography ion trap time-of-flight mass spectrometry.

Cystic fibrosis is a life-threatening genetic disease that causes damage to the lungs. Ivacaftor, the first drug to target the underlying defect of the disease caused by specific mutations, improves outcomes and reduces hospitalizations. In this study, quantitative determination of ivacaftor was performed by liquid chromatography, while high-resolution mass spectrometric analyses were performed for qualitative determination. The validation studies of the developed methods were performed according to International Conference on Harmonisation Q2(R1) guideline. Ivacaftor was separated from its degradation product by using Phenomenex Kinetex C18 (150 × 3 mm, 2.6 µm) column. The isocratic mobile phase for binary pump configuration was 0.1% (v/v) formic acid in water and 0.1% (v/v) formic acid in acetonitrile (27:63) (v/v), pH = 2.5; the flow rate of 0.25 mL/min was used in all methods. In the degradation studies, five degradation products were identified using high-performance liquid chromatography ion trap time-of-flight mass spectrometric analyses: three of them have never been reported up to date; whereas the other two were existing in the literature and they were having Chemical Abstracts Services registry numbers since they were synthesized before for various other purposes. Also, analysis of an in-lab prepared chemical equivalent of Kalydeco® and interlaboratory comparison were performed.

Green analytical chemistry-driven response surface modeling to stability-indicating chromatographic method for estimation of cilnidipine and application of high-performance thin-layer chromatography-mass spectrometry for characterization of degradation products.

Cilnidipine is a calcium channel blocker that is used to treat cardiac diseases such as angina and high blood pressure. Several column and planar chromatographic methods for estimating cilnidipine in pharmaceutical dosage forms have been documented. However, these method developments have been carried out employing organic solvents such as acetonitrile, methanol, toluene, chloroform, and others as mobile phase components or as sample pretreatment diluents. These organic solvents are neurotoxic and teratogenic to humans and aquatic animals, according to International Council for Harmonization Q3C (R8) recommendations. According to the green analytical chemistry approach, such organic solvents should be reduced or removed during the development of chromatographic methods for environmental protection and the safety of human and aquatic animal life. As a result, the stability-indicating chromatographic estimation of cilnidipine was performed utilizing less toxic organic solvents. To prevent organic solvent waste during method development, mobile-phase optimization was performed using the design of experiment-based response surface modeling. Cilnidipine has been subjected to hydrolysis, oxidation, photolysis, and dry-heat decomposition to determine its stability. The greenness profiles of the suggested and published chromatographic methods were examined using the national environment method index, analytical greenness calculator, green analytical procedure index software, and eco-scale assessment tool.

Development and validation of a stability-indicating, single HPLC method for sacubitril-valsartan and their stereoisomers and identification of forced degradation products using LC-MS/MS.

The aim of this research work was to develop and validate a stability-indicating, single reversed-phase HPLC method for the separation of five impurities, including enantiomers, diastereomers, and degradation products in sacubitril-valsartan tablets. The method was developed using a Chiralcel OJ-RH column (150 × 4.6 mm, 5 µm) at 45°C with a gradient program of (T/%B) 0.01/25, 10.0/25, 25/38, 37.0/45, 39.0/25, and 45.0/25 at a flow rate of 0.8 ml/min. Mobile phase A consisted of 1 ml of trifluoroacetic acid in 1000 ml of Milli-Q water. Mobile phase B consisted of 1 ml of trifluoroacetic acid in a mixture of acetonitrile and methanol in the ratio of 950:50 (v/v). Sacubitril, valsartan, and their five impurities were monitored at 254 nm. Degradation was not observed when sacubitril-valsartan was subjected to heat, light, hydrolytic, and oxidation conditions. In acid degradation study (1 N HCl/60°C/2 h) impurity 1 (m/z 383.44) was formed, and in base degradation study (0.1 N NaOH/40°C/1 h) impurities 1 and 5 (m/z 265.35) were formed; both impurities were confirmed using LC-MS. The degradation products, enantiomers, and diastereomers were well separated from sacubitril and valsartan, proving the stability-indicating power of the method. The developed method was validated per the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use guidelines. The inter- and intra-day percentage relative standard deviation for sacubitril, valsartan, and their five impurities was less than 5.2%, recovery of the five impurities was between 93 and 105%, and linearity was ≥0.999. The limit of detection was 0.030-0.048 µg/ml, and the limit of quantification was 0.100-0.160 µg/ml.

A stability-indicating, reversed-phase HPLC method for quantification of assay and organic impurities in doxycycline hyclate bulk and parenteral dosage forms.

The aim of this study is to develop a stability-indicating, reversed-phase HPLC method for the quantification of assay and organic impurities (process and degradation) of doxycycline hyclate in a doxycycline injectable formulation. Both the active and dosage forms are officially present in the USP monograph, and assay and impurity methods are provided by separate UPLC techniques, which are highly sensitive to the flow rate and temperature, considering the quality control requirements and user-friendliness. A simple stability-indicating HPLC method with a shorter run time was developed for the simultaneous quantification of assay and impurity. The method was developed using HPLC with a gradient program and a reversed-phase Waters XBridge BEH C8 column (150 × 4.6 mm, 3.5 µm i.d.). Mobile phase A consisted of phosphate buffer (pH 8.5, 25 mM potassium phosphate, 2 mM ethylenediaminetetraacetic acid, and 0.5 ml of triethylamine). Mobile phase B consisted of methanol with a flow rate of 1.7 ml/min, a column temperature of 55°C, a UV wavelength of 270 nm, and an injection volume of 25 µl. Modern research represents a concomitant method for quantifying assay and organic impurities of doxycycline hyclate (active form) and doxycycline for injection (dosage form). The assay and impurity method were validated per United States Pharmacopeia (USP) 1225 and International Conference on Harmonization (ICH) guidelines. The retention time of doxycycline and degradation impurity, 4-epidoxycycline, was about 9.8 and 6.4 min, respectively. The linearity range of doxycycline and 4-epidoxycycline was 0.5-150 and 0.5-18 µg/ml, respectively. The percentage of recovery of doxycycline and 4-epidoxycycline was 98.7-100.6% and 88.0-112.0%. Validation of the analytical method demonstrated that the method is suitable, specific, linear, accurate, precise, rugged, and stability indicating for estimating the assay, known and degraded impurities of doxycycline, and doxycycline for injection.

Identification and structural characterization of major stress degradation products of halcinonide by liquid chromatography-high-resolution mass spectrometry.

Halcinonide is a topical corticosteroid approved by the US Food and Drug Administration (FDA), known for its anti-inflammatory and antipruritic properties. The therapeutic benefits of halcinonide have rendered it an effective treatment regimen for various dermatological conditions such as psoriasis, dermatitis, and eczema. However, stability of the drug substance is a prerequisite in determining the therapeutic efficacy and plays a crucial role during formulation development and long-term storage. As corticosteroids are highly susceptible to degradation, the current study aims to expose halcinonide to different stress conditions and understand its stability behavior. An HPLC method was developed for the separation of halcinonide and its degradation products. Separation was accomplished in gradient mode using an Eclipse Plus C18 column (250 × 4.5 mm, 5 µm) with ammonium formate (10 mM, pH 6.5) and acetonitrile as the mobile phases. LC-Q-TOF/MS/MS studies were conducted on halcinonide, which led to the identification of degraded products using optimized mass parameters. A potential mechanistic degradation pathway for halcinonide, along with the major identified degradation products has been established. The chromatographic method that was developed has been validated in compliance with the Q2(R1) guideline of the International Council for Harmonization. ProTox-II was used to perform in silico toxicity studies in order to evaluate the toxicity potential of both halcinonide and the identified degradation products.

Stability-indicating method development and validation for quantitative estimation of assay and organic impurities of antiviral drug baloxavir marboxil in drug substance and pharmaceutical dosage form using HPLC and LC-MS methods.

Baloxavir marboxil (BXM) is a polymerase acidic endonuclease inhibitor used as an antiviral drug. A simple, reliable, and robust liquid chromatographic method was developed and validated per International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) Q2(R1) for estimating the assay and impurities of BXM in drug substance and pharmaceutical formulations. The chromatographic separation was carried out on C18 (100 × 4.6 mm, 5 µm) with binary solvent delivery system (A:0.1% trifluoroacetic acid in water; B:0.1% trifluoroacetic-acid in acetonitrile) along with detection wavelength of 260 nm, column temperature of 57°C, flow of 1.2 mL/min and injection volume of 10 µL. All five known impurities and unknown impurities were separated well with resolution >1.7 and were estimated accurately without any interference. Recovered values and regression value were 99.5%-101.2% and R2  > 0.999, respectively. The recovery and linearity studies covered from 50% to 150% for assay, and quantitation limit, 120% for five BXM impurities. Stability-indicating property of the HPLC developed method was assessed from the forced degradation studies. The mass spectral data of unknown impurity formed under oxidation stress condition were discussed. The developed method was also successfully utilized for stability sample analysis of drug substance and tablet dosage form.

Stability-indicating method development and validation for quantitative estimation of organic impurities of the antidiabetic drug glipizide in drug substance and pharmaceutical dosage form using HPLC.

Glipizide is an antidiabetic drug used for the treatment of type 2 diabetes. A simple, reliable and robust reverse-phase liquid chromatographic method (RP-HPLC) was developed and validated as per International Conference on Harmonization Q2(R1) for estimating the impurities of glipizide in pharmaceutical formulations. The chromatographic separation was carried out on a Phenomenex Luna C18 (2), 250 × 4.6 mm, 5 µm with a binary solvent delivery system [MP-A, a homogenous mixture of water and acetonitrile in a ratio of 90:10 (v/v) and 1 ml of orthophosphoric acid; and MP-B, a homogenous mixture of water and acetonitrile in a ratio of 10:90 (v/v) and 1 ml of orthophosphoric acid] with a detection wavelength of 225 nm, a column temperature of 30°C, a flow rate of 1.5 ml/min, and an injection volume of 20 µl. All process, degradant and unknown impurities were separated well with a resolution >2.2 and were estimated accurately without any interference. The recovered values and regression values were 98.7-100.5% and R2 > 0.9999, respectively. The recovery and linearity studies covered the quantitation limit to 150% of the specification limit. The stability-indicating properties of the developed RP-HPLC method was assessed from the forced degradation studies. The developed method was successfully applied for real-time sample analysis of the glipizide dosage form.