In the display industry, when making Array substrates with Cu process, the cleaning treatment will cause the corrosion of the Cu film. Through process adjustment, this paper has obtained the method that can control the mura brought by Cu corrosion within the specification. The corrosion products were analyzed by X‐ray photoelectron spectroscopy and Energy Dispersive Spectrometer. Surface morphology after cleaning was studied by scanning electron microscopy. We confirmed that the main constituent of mura was Cu(OH)2, and EUV irradiation to convert Cu2O into CuO was the key, which provided a theoretical basis for thoroughly solving the related problem.

Background: Minodronic acid (MA) is a third-generation nitrogen-containing heterocyclic bisphosphonate used to treat osteoporosis. In the process of starting materials research and preparation, the key intermediate impurities and degradation impurities have a great impact on the quality control of the drug. Objective: A sensitive, reliable high-performance liquid chromatography (HPLC) method was developed and validated for the quantitative determination of MA and its related impurities (a total of 6 compounds, including 2 new impurities). Methods: The separation was achieved on an InertSustain ODS-4 C18 (250 mm×4.6 mm, 5 μm) column using the mixture of 0.01 mol/L sodium pyrophosphate and 1 mmol tetrabutylammonium phosphate (the mobile phase pH was adjusted to 7.80 by phosphonic acid). Results: The quantitative analytical method was fully validated with respect to linearity (r>0.999), sensitivity (limit of detection<35 ng/mL), precision, accuracy (the recovery was between 98.7% and 104.2%), and robustness. Six process-related impurities in Minodronic Acid (MA) bulk drugs were determined by high-performance liquid chromatography (HPLC). Furthermore, except for two starting materials, other four impurities were identified and characterized as 2-(imidazo[1,2-a] pyridin-3-yl) ethyl acetate (Imp-C), 2-(imidazo [1,2-a] pyridin- 3-yl)acetic acid (Imp-D), 3-(2-hydroxy-2,2- diphosphonoethyl)-4H-imidazo [1,2-a] pyridine -4- oxide (Imp-E) and 2,5- Dihydroxy- 3,6-bis(imidazo[1,2-a] pyridine-3-yl methyl) -2,5-dioxo-1,4,2,5- dioxoDiphosphonium-3,6-diyl) bisphosphonic acid (Imp-F) using liquid chromatograph-mass spectrometer (LC-MS), MS/MS, Infrared Radiation and Nuclear Magnetic Resonance spectroscopy (1H-NMR and 13C-NMR). To the best of our knowledge, two of them (Imp-E and Imp-F) are new compounds and have not been reported previously. Conclusion: The HPLC method was developed and optimized, which could be applied for quantitative detection of the impurities, and further quality evaluation of MA.

Background: Perampanel (PER) is a third-generation anti-epileptic drugs (AEDs). Several methods have been developed for the quantification of perampanel in plasma. The pharmacokinetic characteristics of perampanel in healthy Chinese Ssubjects have not been comprehensively reported. Objective: A simple, fast and sensitive LC-MS/MS method was established and validated for the quantification of perampanel in human plasma and its application to a bioequivalence study. Methods: Chromatographic separation was accomplished on a ZORBAX Eclipse XDB-Phenyl column (4.6 mm × 75 mm, 3.5 μm) using a binary gradient with mobile phase (A) (water containing 5 mmol/L ammonium acetate containing and 0.1% formic acid) and (B) (acetonitrile-water (95:5, v/v)) at a flow rate of 0.9 mL/min and sample preparation was by one-step protein precipitation via acetonitrile. Results: The total run time in this study was 4.5 min and the retention time of perampanel and perampanel-d5 (internal standard) were 2.30 min and 2.32 min, respectively. The method was developed and validated over the concentration range of 2.00-500 ng/mL for perampanel, with correlation coefficient greater than 0.9992. The inter-day precision was 3.1%-3.8% and accuracy 98.9%-103.5%. The intra-day precision was 2.4%-6.8% and accuracy 97.6%-104.9%. The extraction recovery ranged from 99.23%-103.84% and the matrix effect was not significant. Perampanel was proved to be stable in solution and human plasma under the different tested conditions. The validated method was successfully applied to a randomized, open-label, 2-period, crossover bioequivalence study in healthy Chinese subjects, and the results indicated that bioequivalence was achieved for 2 formulations of the 4-mg perampanel tablet under both fasting and fed conditions, and both treatments were safe and well tolerated by all study subjects. Conclusion: The validated method was successfully applied to a bioequivalence study of perampanel in human plasma and has achieved satisfactory results.