Stability-Indicating Method Development and Validation for Quantitative Estimation of Assay and Organic Impurities of anti-viral 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 anti-viral drug. A simple, reliable, and robust liquid chromatographic method was developed and validated per 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 x 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 50-150% for assay, and quantitation limit (QL) - 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 was discussed. The developed method was also successfully utilized for stability samples analysis of drug substance and tablets dosage form.

Degradation pathways and impurity profiling of the anticancer drug apalutamide by HPLC and LC-MS/MS and separation of impurities using Design of Experiments

Apalutamide, an androgen receptor inhibitor, is used to treat prostate cancer. A stability-indicating high-performance liquid chromatography method was developed for the estimation of assay and organic impurities of apalutamide in drug substance and in tablet dosages using Design of Experiments. The chromatographic separation was achieved within 30 min using Atlantis dC₁₈ , 100 × 4.6 mm, 3.0 μm and the binary gradient program (10 mm KH₂ PO₄ , pH 3.5; acetonitrile). The detection wavelength, flow rate, column temperature and injection volume used were 270 nm, 1.0 ml/min, 45°C and 10 μl, respectively. The interaction of independent variables (pH, column temperature and flow rate) and their influences on HPLC parameters were studied using a central composite design, and then the peak separation and elution behaviors between apalutamide and its seven impurities were determined. The method validation was performed for linearity, detection limit, quantitation limit, accuracy, precision and robustness as per the International Conference on Harmonization. A high-quality recovery with good precision (91.7-106.0%) and correlations (r²  > 0.997) within a linear range of 0.12-2.24 μg/ml (0.05-0.3%, w/w) were achieved consistently for assay and organic impurities of apalutamide. The stability-indicating characteristics of the proposed method were assessed through forced degradation and mass balance studies. An effort was made to figure out the chemical structures of newly formed degradation products (DP1-DP5) using LC-MS/MS.

Impurity profiling and stability-indicating method development and validation for the estimation of assay and degradation impurities of midostaurin in softgel capsules using HPLC and LC-MS

Midostaurin (MDS) is used for the treatment of acute myeloid leukemia, myelodysplastic syndrome, and advanced systemic mastocytosis. MDS softgel capsule samples were subjected to stress testing per International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use guidelines for impurity profiling study. MDS underwent extensive degradation under stress testing (acid, alkaline, oxidative, photolytic, thermolytic, and hydrolysis conditions) and formed four degradation products (DPs). MDS and its DPs were separated well from one another with good resolution using reserved-phase HPLC using an Inertsil ODS-3V column (250 × 4.6 mm, 5 μm) and a mobile phase of ammonium formate (40 mM) and acetonitrile. The stability-indicating characteristic of the newly developed method was proven for the estimation of MDS assay, and its organic impurities were free from interference. The validated method exhibited excellent linearity, accuracy, precision, specificity, detection limit, and quantitation limit within 25 min run time. Stress testing, robustness, and solution stability were performed to ensure the continuous performance of the developed method. The peak fractions of DPs formed under stress testing were isolated and characterized using LC-MS, ¹ H and ¹³ C NMR, IR, and UV-Vis. The structure of the major DPs was predicted as DP1 based on the spectral data. The proposed method is effectively used for MDS in bulk drug and finished formulations in the pharmaceutical industry.