Development and Validation of a Stability-indicating Method for Ibrutinib: Identification and Separation of Degradation Products, Known and Genotoxic Impurities Using RP-HPLC/PDA and QDa Mass Detectors

Structural Elucidation of Novel Degradation Impurities of Ibrutinib in Ibrutinib Tablets Using Preparative Chromatography, LCMS, HRMS and 2D NMR Techniques

Ibrutinib is an orally administered compound that functions as an irreversible covalent inhibitor of the Bruton tyrosine kinase, an essential element in multiple cellular processes including B-cell differentiation, proliferation, migration, survival and apoptosis. The compound has been found to demonstrate efficacy against a range of B-cell malignancies. The drug product is available in oral tablet and capsule formulations. The drug degradation profiles of tablets dosage form were assessed in accordance with regulatory guidelines. The results indicate that the drug substance is susceptible to alkaline and oxidative stress. The oxidation degradation led to the identification of three significant unknown degradation impurities. The three compounds were isolated through the application of preparative liquid chromatography, and their structures were determined using analytical techniques such as liquid chromatography-mass spectrometry, high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy. Utilizing structural elucidation data, predictions were made regarding the composition of impurities, revealing them to be novel degradation impurities that bear structural resemblance to ibrutinib. Additionally, potential pathways for the formation of the impurities were proposed.

Valbenazine isomers and enantiomer determination by chiral normal phase liquid chromatography

A novel, simple, specific, rapid, enantioselective normal phase chiral high-performance liquid chromatographic method with amylose-based Chiral Pak IG-3(250 × 4.6 mM) 3.0 μM column was developed and validated for separation and quantification of isomers and enantiomer of Valbenazine. The mobile phase composed of n-Heptane, isopropyl alcohol, dichloromethane, ethanol, and diethylamine in the ratio of 70:10:15:5:0.1 (V/V/V/VV) with a gradient flow rate was applied. The injection volume was 10 μl, and detection was carried out using a photodiode array detector at 282 nM. The column compartment was set at 35°C. The resolution between the enantiomer and isomers was found to be more than 2.0. The method was linear over the concentration range of limit of quantitation to 250% for isomers and enantiomers. The method was found to be robust with column temperature. The proposed chiral method is applicable for the determination of isomers and enantiomer of Valibenazine and was successfully used in the quality control of bulk drug manufacturing and pharmaceuticals.

Identification and characterization of stress degradation products of ibrutinib by LC-UV/PDA and LC-Q/TOF-MS studies

The anticancer drug ibrutinib was subjected to stress degradation studies under the ICH-prescribed hydrolytic, photolytic, oxidative and thermal stress conditions, and its degradation behavior was studied. A significant degradation was noted for the drug under acidic/alkaline hydrolytic, acid/alkaline photolytic, and oxidative conditions. The UPLC-UV/PDA studies revealed the generation of six degradation products (I-VI), and these were adequately resolved from the drug under the developed chromatographic conditions over a Kinetex® C18 (100 mm×4.6 mm; 2.6 μm) column employing isocratic elution method. Detection wavelength was selected as 289 nm. The UPLC-UV/PDA method conditions were extrapolated to UPLC-MS/TOF studies. All the six degradation products were found to be ionized in the total ion chromatogram, and the products could be identified and characterized from their mass spectral data. The possible degradation route of ibrutinib leading to generation of various products was also postulated.

Enantioseparation and ecotoxicity evaluation of ibrutinib by Electrokinetic Chromatography using single and dual systems

In this work, two chiral methods enabling the separation of ibrutinib enantiomers were developed by Electrokinetic Chromatography. A cyclodextrin (CD) or a mixture of the CD and a chiral ionic liquid (CIL) was used as chiral selector. Using the single CD system, seven neutral and six anionic CDs were tested in a formate buffer at pH 3.0 working in positive and negative polarity, respectively. The use of sulfated-γ-CD (S-γ-CD) and negative polarity originated the best results considering analysis time and enantioresolution. The optimization of the experimental conditions allowed obtaining the separation of ibrutinib enantiomers in an analysis time of 4.2 min with an enantioresolution value of 1.5. The effect of the addition of fifteen CILs on the enantioresolution was evaluated showing that both analysis time and enantioresolution were generally increased. A mixture of S-γ-CD and [TMA][L-Lys] was selected which provided the separation of ibrutinib enantiomers in 8.1 min with an enantioresolution value of 3.3 under the same experimental conditions as in the case of using the single CD system. The enantiomeric impurity (S-ibrutinib) was the first-migrating isomer when using the single CD and the combined CD/CIL systems, as corresponds to the most desirable situation. Both chiral methods allowed the detection of the enantiomeric impurity up to a 0.1% as established by the International Council on Harmonization. After establishing the analytical characteristics of both chiral methodologies developed, they were applied to the enantiomeric determination of ibrutinib in a pharmaceutical formulation for hospital use marketed as pure enantiomer (R-ibrutinib) and to evaluate the stability and ecotoxicity of racemic ibrutinib and R-ibrutinib on Daphnia magna. The developed methodologies enabled, for the first time, the rapid chiral quantitation of ibrutinib in abiotic and biotic matrices.

Development and validation of apalutamide-related substances method in solid dosage forms using HPLC

A related-substances method was developed for the anticancer drug formulation apalutamide 60 mg tablets and validated using a liquid chromatography gradient elution method. All of the impurities and degradants were separated using the Luna Omega 5 μm Polar C₁₈ , (250 × 4.6) mm HPLC column with a 1.0 ml min^-1 flow rate. The detection was done at 225 nm by injecting the 10 μl of injection volume, controlling the sample temperature at 10°C and maintaining the column compartment temperature at 30°C. The total run time was 85 min. A 0.01 m disodium phosphate dihydrate pH 4.20 ± 0.05 buffer mixed with acetonitrile in the ratio of 73:27 (v/v) was used as mobile phase A. Mobile phase B consisted of water and acetonitrile in the ratio 30:70 (v/v). The proposed method was validated as per the current regulatory guidelines. The method precisions (RSD) at 100% specification level were 1.41, 1.74, 1.84, and 1.66% for the four impurities. The accuracy results were obtained between 96.0 and 106.3% for the limit of quantitation to the 150% level. The standard and sample solutions stability were established for 44 h at 10°C. The correlation coefficient (r) value was >0.999 for all four impurities, indicating good linearity between the concentration and peak response: 0.9999, 0.9999, 0.9999 and 1.0000. These results show the method's linearity. The three filter compatibility was proved and it was concluded that 0.45 μm Nylon, PTFE and PVDF filters are suitable. The robustness of the method was established by varying the conditions. The method specificity was proved and the forced degradation data reveal the method's stability-indicating nature.

Unique Quality by Design Approach for Developing HPLC and LC-MS Method for Estimation of Process and Degradation Impurities in Pibrentasvir, Antiviral Agent for Hepatitis C

Pibrentasvir (PIB) was approved for treating hepatitis C patients. A specific, accurate, linear, robust, and stability-indicating method was developed and validated for determining degradation impurities present in the PIB drug substance by studying the quality by design (QbD) principles. All identified degradation impurities were separated with the stationary phase HALO C18, 150 mm × 4.6 mm, 2.7 μm. Mobile phase A contains pH 2.5 phosphate buffer and acetonitrile in the ratio of (70:30, v/v), and mobile phase B contains water and acetonitrile in the ratio of (30:70, v/v), respectively. The chromatographic conditions were optimized, such as flow rate of 0.8 mL/min, UV detection at 252 nm, injection volume of 20 μL, and column temperature of 40 °C. The proposed method was validated per the current ICH Q2 (R1) guidelines. The recovery study and linearity ranges were established from limit of quantification (LOQ) to 300% optimal concentrations. The method validation results were between 98.6% and 106.2% for recovery, and linearity r ² was more than 0.999 for all identified impurities. The method precision results achieved below 5% relative standard deviation (RSD). The forced degradation results demonstrated that the drug was sensitive to chemical stress conditions. During the stress study, degrading impurities were identified by the LC-MS technique and the mechanism pathway. A QbD-based experimental design (DoE) approach was used to establish the robustness of the method.

Regulatory Perspective Development and Validation of Novel RP-HPLC Method of Midostaurin Drug Substance using Analytical Quality by Design approach; Identified Major Degradation Compounds Mass by Using LC-MS technique

Midostaurin (MTN) was designated as an orphan medicinal product, and it is an emerging drug for treating acute myeloid leukemia and advanced systematic mastocytosis, respectively. The proposed method was developed and validated to evaluate related impurities of MTN. Those impurities were separated by using YMC Trait C18 ExRS, (150 mm × 4.6 mm), 3 μm column. The mobile phase A consists of a 10 mM concentration of phosphate buffer adjusted to pH 3.0 with diluted orthophosphoric acid and mobile phase B contains 90 % acetonitrile with 10 % water. The optimized chromatographic conditions such as flow rate 0.5 mL min^-1 , injection volume 10 μL, UV detection at 290 nm, and a linear gradient program set upto 65 minutes. It was developed through an analytical QbD approach. A systematic flow chart explained the evaluation, control, and life cycle management method. As part of the method evaluation, a risk assessment was conducted. It has been validated as per current ICH guidelines. The recovery study and linearity ranges were established from LOQ to 150 % optimal concentrations. The validation results were found between 95.5 to 102.5 % for recovery and r² 0.9998 to 0.9999 for linearity of all identified impurities. The method precision results were achieved below 10% of RSD. Performed forced degradation studies in chemical and physical stress conditions. The compound was sensitive to chemical stress conditions. During the study, the analyte was degraded, converted into identified degradation impurities, and found its molecular mass by the LC-MS technique.

Unique liquid chromatography technique for the determination of mirabegron in the presence of polymers; robustness by design expert in the light of quality by design

The current study is designed to estimate mirabegron in the presence of high molecular weight of polymers using a unique liquid chromatography method and sample preparation technique. The proposed method is significant because of many analytical issues faced during the development studies. Based on the experimental results, we finally achieved the stability-indicating power of the method. The adequately prepared mobile phase in the ratio of pH 2.0 buffer and acetonitrile (80:20) v/v, respectively. And the buffer pH 2.0 was prepared as follows 8.7 ml of perchloric acid, 2 ml of triethylamine, and 3.0 g sodium hydroxide into 1L of water mixed well. The system suitability parameters were achieved by waters X-Bridge C18 (4.6 mm × 150 mm, 3.5 μm) column and mobile phase. The optimized chromatographic conditions include column temperature of 45°C, a flow rate of 1.0 mL min^-1 ; an injection volume of 5μL; UV 247 nm, and 15 minutes runtime. It's been validated and transferred to QC as per ICH Q2(R1) and Chinese pharmacopeia 2020 edition <9101> & <9100>. Found the recovery and linearity results between 99.0% to 101.0%; (r² ) 0.9998. Established the method robustness study by utilizing the Design of Experiments (DoE) part of the Quality by Design (QbD) concept. The method's stability-indicating nature was proven by a forced degradation study, all the conditions analyte peak purity were passed, and achieved mass balance. It has been used to determination of mirabegron in the assay, content uniformity, blend uniformity, and cleaning samples. It's a user-friendly and cost-effective method.

A simple isocratic LC method for quantification of trace-level inorganic degradation impurities (ferricyanide, ferrocyanide, nitrite, and nitrate) in sodium nitroprusside injection and robustness by quality using design approach

This study developed and validated a trace-level quantification inorganic impurities method using reversed-phase HPLC and performed the robustness check using quality-by-design approach by varying the multiple factors simultaneously. This method is economical and simple and exhibits its stability-indicating nature [for the determination of ferrocyanide ([Fe(CN)₆]^4- ), ferricyanide ([Fe(CN)₆ ]^3- ), nitrate (NO₃ ^- ), and nitrite (NO₂ ^- )] in sodium nitroprusside (SNP) drug substance and liquid dosage form. Chromatographic separation was achieved using a USP L43 column (ACE PFP, 150 × 4.6 mm, 3 μm) with a simple isocratic elution. The buffer consists of potassium dihydrogen phosphate (50 mM), tetrabutylammonium hydrogen sulfate (9 mM), and tetrabutylammonium hydroxide (25 mM). The buffer pH was adjusted to 7.2 with tetrabutylammonium hydroxide. The mobile phase was mixed with the buffer and acetonitrile (68:32 v/v). The flow rate was 0.8 mL/min, column temperature was maintained at 30°C, and injection volume was 5.0 μL. The SNP impurities were monitored at 225 nm using a UV detector. Further, the method was validated per the International Council for Harmonisation (ICH) guidelines, and forced degradation studies were carried out under different stress conditions. The detector responses were plotted against concentrations, and correlation was linear (r > 0.999) over the range of 0.8-7.5 μg/mL for ferricyanide; 1.0-37.5 μg/mL for SNP; and 0.2-7.5 μg/mL for ferrocyanide, nitrite, and nitrate. The method repeatability was established for all the impurities with relative standard deviation (%), and the results were found to be less than 2.0.

A validated stability-indicating reversed-phase-HPLC method for dipyridamole in the presence of degradation products and its process-related impurities in pharmaceutical dosage forms

In this study, we developed and validated a method to determine dipyridamole-related impurities in pharmaceutical dosage forms using the reversed-phase-HPLC technique. All impurities were separated on a YMC pack C8 (150 mm × 4.6 mm, 3.0 μm) analytical column using a suitable mobile phase. Mobile phase A was 10 mM concentration of phosphate buffer (pH adjusted to 4.7 by adding diluted orthophosphoric acid) and mobile phase B was buffer:acetonitrile:methanol (at the ratio of 30:40:30 v/v). The optimized chromatographic conditions used in the experiment were as follows: flow rate, 1.0 mL/min; injection volume, 10 μL and column temperature, 35°C. Chromatographic detection was performed at 295 nm. The stressed samples were analyzed for degradation under acidic, basic, peroxide, water hydrolysis, and physical degradation conditions. The proposed method was validated according to International Conference on Harmonization (ICH) guidelines, and found to be specific, linear, accurate and have a robust stability-indicating nature. The method showed excellent linearity from limit of quantification (LOQ) to 150% level of concentrations for all impurities. The correlation coefficient (r² ) for all impurities was between 0.995 and 0.999. The recovery study was performed from LOQ to 150% level concentrations, with mean recovery values between 92.9% and 103.2%, respectively. The developed method can be used to determine dipyridamole and its relative impurities. The degradation and validated study results indicate its stability-indicating nature. Therefore, the method can be used in pharmaceutical research and development and quality control departments.

Stability-indicating reversed-phase-HPLC method development and validation for sacubitril/valsartan complex in the presence of impurities and degradation products: Robustness by quality-by-design approach

According to current regulatory guidelines, a stability-indicating method has been developed to determine the impurities in sacubitril (SCB) and valsartan (VLS) tablet dosage forms and perform robustness studies using the design of experiments approach. The present study was initiated to understand quality target product profile, analytical target profile, and risk assessment for method variables that affect the method response. A reversed-phase-HPLC system was equipped with a Phenomenex Gemini-NX C₁₈ column (150 × 4.6 mm, 3 μm) and a photo diode array detector. A gradient mobile phase was used in this research work. The detection was performed at 254 nm; the flow rate was 1.5 mL/min, and the column temperature was maintained at 30°C. The proposed method was validated per the International Council for Harmonisation Q2 (R1) guidelines. The coefficient of correlation was >0.999 for all impurities. The limits of detection and quantification were evaluated for SCB, VLS, and all impurities. The precision and accuracy were obtained for SCB, VLS, and their related impurities. Intra- and inter-day relative standard deviation values were less than 10.0%, and the recoveries of impurities varied between 90.0 and 115.0%. Based on the validation results, the proposed DoE method can estimate SCB and VLS impurities in the finished dosage form.

LC and LC-MS/MS studies for identification and characterization of new degradation products of ibrutinib and elucidation of their degradation pathway

Forced degradation/stress degradation studies of ibrutinib drug were done in hydrolytic (acidic, alkaline and neutral), thermal, photolytic and oxidative degradation conditions in different temperature conditions as per International Conference on Harmonization (ICH) guideline Q1A(R2) in order to identify and characterize degradation products (DPs) of ibrutinib. The study revealed that ibrutinib is extremely sensitive to oxidative degradation even at room temperature. The drug substance is highly sensitive to alkaline hydrolysis and susceptible to acidic hydrolysis at 80 °C temperature condition, whereas found stable in neutral, photolytic and thermal stress conditions. Successful separation of ibrutinib and its ten degradation products formed during stress degradation condition were observed using Waters Acquity UPLC C-18 stationary phase (100 mm × 2.1 mm, 1.7 μm) with gradient elution using mobile phase consisting of Eluent-A: ammonium acetate (20 mm, pH-6) and Eluent-B: acetonitrile. The detection was carried out at 215 nm wavelength. Flow rate was set at 0.3 mL/min with injection volume of 5 μL. The drug substance degraded to one degradation product (DP-I) in acidic hydrolysis, five DPs (DP-I, DP-II, DP-V, DP-VIII and DP-IX) in basic hydrolysis and five DPs (DP-III, DP-IV, DP-VI, DP-VII and DP-X) in oxidative degradation condition. A novel and highly sensitive HRMS/MS/TOF method was developed to identify and characterize all the ten DPs formed during stress study. All the DPs were characterized using ESI positive mode. Except DP-I, all the degradation products formed were found to be new degradation impurities and their fragmentation pathways have never been reported earlier. The proposed mechanism and pathway of degradation products of ibrutinib were discussed and outlined.