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Journal articles on the topic 'Impurity quantitation'

Author: Grafiati

Published: 4 June 2021

Last updated: 17 February 2022

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1

Mule, Kishorkumar L., and Dnyandeo B. Pathare. "DEVELOPMENT AND VALIDATION OF ANALYTICAL METHOD FOR ISOSULFAN BLUE BY LIQUID CHROMATOGRAPHY." International Journal of Applied Pharmaceutics 9, no. 2 (2017): 42. http://dx.doi.org/10.22159/ijap.2017v9i2.16904.

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Objective: To develop and validate new, simple and rapid analytical method for determination of related impurities in isosulfan blue drug substances by the liquid chromatographic method as per ICH guidelines.Methods: The chromatographic separation obtained between drug substance i.e. isosulfan blue and its related impurities (Impurity-A, Impurity-B and Impurity-C) on C18 (100 x 2.00 mm) 1.9µ UPLC column using a mobile phase system containing 0.1 % perchloric acid in water (Mobile phase A) and 0.1 % perchloric acid in mixture of 30 volumes of water and 70 volumes of acetonitrile (Mobile Phase B

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2

Casella, R., S. Boudreau, James A. Wesley, and Robert D'Aloise. "Quantitative measurement of crystalline impurity in a pharmaceutical tablet by X-ray powder diffraction and method validation." Powder Diffraction 28, no. 3 (2013): 222–30. http://dx.doi.org/10.1017/s0885715613000432.

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A powder X-ray diffraction method was developed and validated to measure the crystalline impurity 4-(5-cyclopentyloxy-carbonylamino-1-methyl-indol-3-ylmethyl)-3-methoxy-N-o-tolylsulfonylbenzamide hydrate in a pharmaceutical tablet ranging from 0.6 to 3% (w/w). The calibration plot was found to be linear with a correlation coefficient (r2) of 0.996, and was reproducible among operators. The detection limit was determined to be 0.6% with a signal-to-noise ratio of 3:1. The quantitation limit was determined to be 1% with a signal-to-noise ratio of 5:1. Instrument precision at the quantitation lim

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3

Lasdun, A. M., R. R. Kurumbail, N. K. Leimgruber, and A. S. Rathore. "Validatibility of a capillary isoelectric focusing method for impurity quantitation." Journal of Chromatography A 917, no. 1-2 (2001): 147–58. http://dx.doi.org/10.1016/s0021-9673(01)00662-8.

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4

Denton, Justin R., Renee K. Dermenjian, and Bing Mao. "Development of an enantiomeric separation of d & l valine as their corresponding isoindole adducts by RP-HPLC for utilization of the l-valine toward pharmaceutically relevant materials." Anal. Methods 6, no. 16 (2014): 6565–70. http://dx.doi.org/10.1039/c4ay01069h.

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5

Nath, Dipankar, and Bidhya Sharma. "Impurity Profiling-A Significant Approach in Pharmaceuticals." Current Pharmaceutical Analysis 15, no. 7 (2019): 669–80. http://dx.doi.org/10.2174/1573412914666181024150632.

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There has been ever increasing interest in impurities present in Active Pharmaceutical Ingredient’s (API’s). Nowadays, not only purity profile but also impurity profile has become mandatory according to the various regulatory authorities. In the pharmaceutical world, an impurity is considered as an inorganic or organic material, or residual solvents other than the drug substances, or ingredients, arising out of synthesis or unwanted chemicals that remains with APIs. Impurity profiling includes identification, structure elucidation and quantitative determination of impurities and degradation pr

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6

Kuz’mina, Nataliya E., Sergey V. Moiseev, Mikhail D. Khorolskiy, and Anna I. Lutceva. "Development and Validation of 2-Azaspiro [4,5] Decan-3-One (Impurity A) in Gabapentin Determination Method Using qNMR Spectroscopy." Molecules 26, no. 6 (2021): 1656. http://dx.doi.org/10.3390/molecules26061656.

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The authors developed a 1H qNMR test procedure for identification and quantification of impurity A present in gabapentin active pharmaceutical ingredient (API) and gabapentin products. The validation studies helped to determine the limit of quantitation and assess linearity, accuracy, repeatability, intermediate precision, specificity, and robustness of the procedure. Spike-and-recovery assays were used to calculate standard deviations, coefficients of variation, confidence intervals, bias, Fisher’s F test, and Student’s t-test for assay results. The obtained statistical values satisfy the acc

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7

Castro-Puyana, María, Carmen García-Ruiz, Alejandro Cifuentes, Antonio L. Crego, and Maria Luisa Marina. "Identification and quantitation of cis-ketoconazole impurity by capillary zone electrophoresis–mass spectrometry." Journal of Chromatography A 1114, no. 1 (2006): 170–77. http://dx.doi.org/10.1016/j.chroma.2006.02.030.

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8

Mount, Dwight L., James W. Miles, and Frederick C. Churchill. "Liquid Chromatographic and Spectroscopic Characterization of Pentamidine Isethionate and Impurities in Bulk Drug and Injectables." Journal of AOAC INTERNATIONAL 69, no. 4 (1986): 624–29. http://dx.doi.org/10.1093/jaoac/69.4.624.

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Abstract A liquid chromatographic (LC) method is described for evaluating purity of pentamidine isethionate (PI), a life-saving drug used in the treatment of Pneumocystis carinii pneumonia, which is a leading cause of death in persons with acquired immunodeficiency syndrome (AIDS). Six potential impurity compounds were synthesized to test the selectivity of the chromatographic system and to permit quantitation of impurities in various lots of PI products. The drug and impurities were separated with gradient elution on a cyano-bonded LC column. The analytic system provided information on the id

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9

Raja, K. Durga, V. Saradhi Venkata Ramana, K. Raghu Babu, et al. "Development and Validation of UPLC-ESI-MS/MS Technique for the Determination of 2-Isopropyl-4-(chloromethyl)thiazole in Ritonavir." Asian Journal of Chemistry 32, no. 7 (2020): 1733–40. http://dx.doi.org/10.14233/ajchem.2020.22677.

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The objective of this work was to develop and validate a rapid, highly sensitive ultra performance liquid chromatography-tandem mass spectrometry (UPLC-ESI-MS/MS) method for the quantification of 2-isopropyl-4-(chloromethyl)thiazole in ritonavir. Chromatographic conditions of this impurity were achieved on an AQUITY UPLC column HSS (high strength silica) T3 column (100 mm long, 2.1 mm internal diameter, 1.8 μm diameter) using a gradient elution with 0.1% formic acid in water and methanol at a flow rate of 0.3 mL/min. LCMS/MS was operated under the multiple reaction mode (MRM) using electrospra

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10

bhatale, Mohan, Neelakandan kaliyaperumal, Gopalakrishnan Mannathusamy, and Gurunathan ramalingam. "Development and Validation of Estimation of Genotoxic Impurity (Triethyl orthoformate content) in 5-methyl-4-isoxazole carboxylic acid (5-MIA) by using GC Technique." Oriental Journal Of Chemistry 37, no. 2 (2021): 348–53. http://dx.doi.org/10.13005/ojc/370212.

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A simple, selective, precise and accurate Gas chromatographic method for determination of Triethyl orthoformate content (Genotoxic impurity) in 5-MIA is reported. The GC method development and validation as per the International Council for Harmonisation (ICH) guidelines Q2(R1). The effective chromatographic separations were achieved on DB-624, 60 m × 0.53 mm ID, with film thickness of 3.0 μm (Fused silica capillary column), Capillary injector temperature of 150°C, and Nitrogen Carrier gas. This method is unique as there is no UV response; hence GC Method was developed for Triethyl orthoformat

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11

Kang, Yanlei, Zhanying Shao, Qiang Wang, Xiurong Hu, and Dongdong Yu. "Quantitation of polymorphic impurity in entecavir polymorphic mixtures using powder X-ray diffractometry and Raman spectroscopy." Journal of Pharmaceutical and Biomedical Analysis 158 (September 2018): 28–37. http://dx.doi.org/10.1016/j.jpba.2018.05.026.

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12

Sun, Jeffrey J., and Daryl A. Roston. "Matrix effects during standard addition quantitation of a trace volatile impurity in a drug substance sample." Journal of Chromatography A 673, no. 2 (1994): 211–18. http://dx.doi.org/10.1016/0021-9673(94)85038-0.

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13

Beaulieu, Normand, Edward G. Lovering, Johanne Lefrancois, and H. Ong. "Determination of Diclofenac Sodium and Related Compounds in Raw Materials and Formulations." Journal of AOAC INTERNATIONAL 73, no. 5 (1990): 698–701. http://dx.doi.org/10.1093/jaoac/73.5.698.

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Abstract A liquid chromatographic method has been developed for determination of drug and related compounds In diclofenac sodium raw material, slow-release, and enteric coated tablets. The method specifies a 5μm octadecylsllane bonded phase column, a mobile phase of tetrahydrofuran-acetonltrlle- buffer, pH 5 (1 + 4 + 8.3), and detection at 229 nm. The method resolves 10 known related compounds with limits of quantitation of 0.2% or less. Seventeen drug raw material samples were evaluated. Total Impurity levels ranged from 0.1 to 0.9%. The method has also been used for determination of drug con

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14

Beaulieu, Normand, Susan J. Graham, Roger W. Sears, and Edward G. Lovering. "Liquid Chromatographic Determination of Alprazolam and Related Impurities in the Drug Substance." Journal of AOAC INTERNATIONAL 75, no. 5 (1992): 801–3. http://dx.doi.org/10.1093/jaoac/75.5.801.

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Abstract A liquid chromatographic method was developed for the determination of alprazolam and 5 known related compounds in drug raw materials. The method is based on a 3 µm cyano column (100 x 4.6 mm), a mobile phase of 0.01% phosphoric acidacetonitrile- methanol (6 + 3 +1), a flow rate of 1.5 mL/min, and detection at 230 nm. The method resolves the related compounds from the drug and from each other. The limit of quantitation for the impurities in drug raw material is less than 0.1%. Impurity levels in 4 drug raw materials were between 0.01 and 0.41 %. The corresponding mean assay values ran

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15

Smith, Marco, and Tony Beck. "Quantitation of a low level coeluting impurity present in a modified oligonucleotide by both LC–MS and NMR." Journal of Pharmaceutical and Biomedical Analysis 118 (January 2016): 34–40. http://dx.doi.org/10.1016/j.jpba.2015.10.019.

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16

Su, Xiaoye, Ruiting Liang, and Jessica A. Stolee. "A facile one-step fluorescence method for the quantitation of low-content single base deamination impurity in synthetic oligonucleotides." Journal of Pharmaceutical and Biomedical Analysis 155 (June 2018): 50–55. http://dx.doi.org/10.1016/j.jpba.2018.03.051.

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17

Raja, K. Durga, V. Saradhi Venkata Ramana, K. Raghu Babu, et al. "Simultaneous and Trace Level Determination of Six Potential Impurities by UPLC-ESI-MS/MS in Antiarrhythmic Drug: Dronedarone Hydrochloride." Asian Journal of Chemistry 32, no. 5 (2020): 1183–90. http://dx.doi.org/10.14233/ajchem.2020.22588.

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Development and validation of six potential impurities by ultra performance liquid chromatography electro spray ionization tandem mass (UPLC-ESI-MS/MS) method for dronedarone hydrochloride drug was accomplished coherent with ICH guidelines. Successful chromatographic separation of dronedarone with its six impurities was attained by using gradient elution mode on RP-UPLC column using three pump mode system of 0.1 % formic acid in water as mobile phase A, methanol as the mobile phase B and solvent mixture of methanol, acetonitrile and water in the ratio of 65:30:5 v/v/v as the mobile phase C. Ch

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18

Chawla, Rajesh Kumar, G. S. N. Koteswara Rao, Umasankar Kulandaivelu, Siva Prasad Panda, and Rajasekhar Reddy Alavala. "A Selective and Sensitive Method Development and Validation of 1,1-Dimethyl-3-Hydroxy-Pyrrolidinium Bromide Impurity in Glycopyrrolate Oral Solution by Liquid Chromatography–Tandem Mass Spectroscopy." Journal of Chromatographic Science 59, no. 6 (2021): 566–75. http://dx.doi.org/10.1093/chromsci/bmab003.

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Abstract Objective A selective and sensitive liquid chromatography–tandem mass spectrometer (LC–MS/MS) method has been developed for the quantification of 1,1-dimethyl-3-hydroxy-pyrrolidinium bromide impurity in glycopyrrolate oral solution. Materials and method The LC–MS/MS analysis was done on X Bridge HILIC (100 × 4.6 mm, 5 μm) analytical column, and the mobile phase used was10 mM ammonium formate with 0.2% formic acid as mobile phase-A and acetonitrile as mobile phase-B with a gradient programme of 5.0 min. The flow rate used was 1.2 mL/min. Triple quadrupole mass detector coupled to posit

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19

Guarise, Cristian, Carlo Barbera, Mauro Pavan, Susi Panfilo, Riccardo Beninatto, and Devis Galesso. "HA-based dermal filler: downstream process comparison, impurity quantitation by validated HPLC-MS analysis, and in vivo residence time study." Journal of Applied Biomaterials & Functional Materials 17, no. 3 (2019): 228080001986707. http://dx.doi.org/10.1177/2280800019867075.

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The success of hyaluronic acid (HA)-based dermal fillers, with more than 2 million minimally invasive procedures conducted in 2016 in the US alone, is due to their hygroscopic properties of biocompatibility and reversibility. The type and density of HA cross-linkage, as well as the manufacturing technology, may influence not only the in vivo persistence but also the safety profile of dermal fillers. 1,4-Butanediol diglycidyl ether (BDDE) is the cross-linker used in most market-leading HA fillers; 1,4-butanediol di-(propan-2,3-diolyl) ether (BDPE) is the major impurity obtained from the HA–BDDE

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20

Killi, Gnana Deepika, Rama Krishna Maddinapudi, Sathis Kumar Dinakaran, and Avasarala Harani. "A novel validated UPLC method for quantitation of lopinavir and ritonavir in bulk drug and pharmaceutical formulation with its impurities." Brazilian Journal of Pharmaceutical Sciences 50, no. 2 (2014): 301–8. http://dx.doi.org/10.1590/s1984-82502014000200009.

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A simple gradient Ultra Performance liquid chromatographic method (UPLC) was developed for determination of lopinavir and ritonavir from its related impurities and assay for the ﬁrst time. This method involves the use of a C18 (Acquity UPLC BEH C18, 50 × 2.1 mm, 1.7 µm) column thermostated at 30 oC using triethylamine (pH 2.2): 0.1% H3PO4 in acetonitrile and methanol (85:15) as mobile phase in gradient elution mode. A Photo Diode Array (PDA) detector set at 215 nm was used for detection with flow rate 0.4 mL/min. This method was validated over the range of limit of quantitation (LOQ) to 50 to

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21

Maheshwari, Priyanka, Neelima Shukla, and Manish Kumar Dare. "Development and Validation of a Novel Stability-Indicating Reversed-Phase Ion-Pair Chromatographic Method for the Quantitation of Impurities in Marbofloxacin Tablets." Journal of AOAC INTERNATIONAL 101, no. 4 (2018): 1021–29. http://dx.doi.org/10.5740/jaoacint.17-0108.

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Abstract A stability-indicating isocratic reversed-phase ion-pair chromatographic method was designed for the separation of impurities in the presence of degradation products. Marbofloxacin tablets and a placebo were exposed to the stress conditions of oxidative, acid, base, humidity, thermal, and photolytic degradation. Significant and moderate degradation was observed in acidic and oxidative stress conditions, respectively. The degradation products were well resolved from the main peak and its impurities, thus proving the stability-indicating analytical method. The method was developed by us

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22

El-Ragehy, Nariman A., Ali M. Yehia, Nagiba Y. Hassan, Mahmoud A. Tantawy, and Mohamed Abdelkawy. "Chemometrics Tools in Detection and Quantitation of the Main Impurities Present in Aspirin/Dipyridamole Extended-Release Capsules." Journal of AOAC INTERNATIONAL 99, no. 4 (2016): 948–56. http://dx.doi.org/10.5740/jaoacint.16-0082.

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Abstract Aspirin (ASP) and dipyridamole (DIP) in combination is widely used in the prevention of secondary events after stroke and transient ischemic attack. Salicylic acid is a well-known impurity of ASP, and the DIP extended-release formulation may contain ester impurities originating from the reaction with tartaric acid. UV spectral data analysis of the active ingredients in the presence of their main impurities is presented using multivariate approaches. Four chemometric-assisted spectrophotometric methods, namely, partial least-squares, concentration residuals augmented classical least-sq

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23

Stolarczyk, Mariusz, Jan Krzek, and Włodzimierz Rzeszutko. "Application of Derivative Spectrophotometry to Simultaneous Determination of Indomethacin and 5-Methoxy-2-methyl-3-indoleacetic Acid in Metindol Injections." Journal of AOAC INTERNATIONAL 87, no. 3 (2004): 592–95. http://dx.doi.org/10.1093/jaoac/87.3.592.

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Abstract Derivative spectrophotometry was employed to develop a rapid and accurate method for simultaneous determination of indomethacin and 5-methoxy-2-methyl-3-indoleacetic acid as its possible impurity in Metindol injections. At the selected wavelengths, 233.04 and 284.65 nm, no interference between the components determined was observed. Under the established experimental conditions, recoveries of the particular components were from 96.14 to 98.17%. Linearity was maintained over a broad range of concentrations, from 11.88 × 10−3 to 35.64 × 10−3 mg/mL for indomethacin and 0.4 to 1.2 mg/mL f

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24

Lacrok, Pauline M., Norman M. Curran, Wing-Wah Sy, Dennis K. J. Goreck, Pierre Thibault, and Pearl K. S. Blay. "Liquid Chromatographic Determination of Amiodarone Hydrochloride and Related Compounds in Raw Materials and Tablets." Journal of AOAC INTERNATIONAL 77, no. 6 (1994): 1447–53. http://dx.doi.org/10.1093/jaoac/77.6.1447.

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Abstract A liquid chromatographic method for the determination of amiodarone hydrochloride and 10 related compounds in drug raw material and for assay of drug in tablets was developed. The method specifies a 3 jxm Hypersil nitrile column (150 × 4.6 mm), a mobile phase of 1 + 1 acetonitrile–ammonium acetate buffer (0.1 M adjusted to pH 6.0 with 0.1 M acetic acid), a flow rate of 1 mL/min, and detection at 240 nm. The lower limit of quantitation of the related compounds is 0.02% or less. Drug contents in 2 raw material samples were 100.1 and 99.9% and ranged from 98.2 to 99.4% in 3 tablet formul

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25

Drapak, Iryna, Borys Zimenkovsky, Liudas Ivanauskas, et al. "HPLC method for simultaneous determination of impurities and degradation products in Cardiazol." Pharmacia 67, no. 1 (2020): 29–37. http://dx.doi.org/10.3897/pharmacia.67.e37004.

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Aim. The aim of study was to develop a simple and accurate procedure that could be applied for the determination of impurities and degradation products in cardiazol. Materials and methods. Separation in samples was carried out with Acquity H-class UPLC system (Waters, Milford, USA) equipped with Acquity UPLC BEH C18 column (2.1 × 50 mm, 1.7 μm) (Waters, Milford, USA). Xevo TQD triple quadrupole mass spectrometer detector (Waters Millford, USA) was used to obtain MS/MS data. Mobile phase A: 0.1% solution of trifluoroacetic acid R in water R; Mobile phase B: acetonitrile R. Samples were chromato

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26

Klimashevich, V. B., E. V. Kokusev, V. V. Gudovich, O. A. Kazyuchits, and A. I. Zhebentyaev. "DEVELOPMENT AND VALIDATION OF THE PROCEDURE FOR QUANTITATIVE DETERMINATION OF IMPURITIES IN TABLETS “RANOLAZIN-NAN”." Vestnik Farmacii 92, no. 2 (2021): 80–92. http://dx.doi.org/10.52540/2074-9457.2021.2.80.

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The article presents the results of the research on the development of the procedure for determining related impurities by high-performance reversed-phase chromatography in the tablets “Ranolazin-NAN”. The conditions for samples preparation of ranolazine tablets, optimal conditions for the gradient mode of chromatography were selected using Zorbax Eclipse Plus C18 column: eluent A - 0,1% triethylamine buffer with pH 6,0 ± 0,1 (diluted with orthophosphoric acid) and acetonitrile in a ratio 70:30 v / v and eluent B - acetonitrile. The effect of pH medium (2,0, 6,0 and 9,0) on the efficiency of t

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27

Darwish, Hany W., Nesma A. Ali, Ibrahim A. Naguib, Mohamed R. El Ghobashy, Abdullah M. Al-Hossaini, and Maha M. Abdelrahman. "Development and validation of a stability indicating RP-HPLC-DAD method for the determination of bromazepam." PLOS ONE 16, no. 3 (2021): e0244951. http://dx.doi.org/10.1371/journal.pone.0244951.

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A reliable, selective and sensitive stability-indicating RP-HPLC assay was established for the quantitation of bromazepam (BMZ) and one of the degradant and stated potential impurities; 2-(2-amino-5-bromobenzoyl) pyridine (ABP). The assay was accomplished on a C18 column (250 mm × 4.6 mm i.d., 5 μm particle size), and utilizing methanol-water (70: 30, v/v) as the mobile phase, at a flow rate of 1.0 ml min-1. HPLC detection of elute was obtained by a photodiode array detector (DAD) which was set at 230 nm. ICH guidelines were adhered for validation of proposed method regarding specificity, sens

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28

Harp, Bhakti Petigara, Marianita Perez-Gonzalez, Hector M. Cordero-Nieves, Rachel S. Pandian, and Bryan K. Bowes. "Determination of Seven Manufacturing Impurities in FD&C Red No. 40 by Ultra-High-Performance Liquid Chromatography." Journal of AOAC INTERNATIONAL 103, no. 1 (2020): 235–43. http://dx.doi.org/10.5740/jaoacint.19-0179.

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Abstract Background: The U.S. Food and Drug Administration batch-certifies color additives to ensure that each lot meets published specifications for coloring food, drugs, and cosmetics. Objective: An ultra-high-performance LC (UHPLC) method was developed to determine seven manufacturing impurities in the monoazo color additive FD&C Red No. 40 (R40). The analytes consist of two intermediates, an impurity originating from one intermediate, a reaction by-product, and three subsidiary colors. The intermediates are 4-amino-5-methoxy-2-methylbenzenesulfonic acid [cresidine-p-sulfonic acid (CSA)

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Belal, F., M. Sharaf EL-Din, M. M. Tolba, and H. Alaa. "Utility of Certain Nucleophilic Aromatic Substitution Reactions for the Assay of Ethamsylate in its Dosage forms and in Presence of its Degradation Product." JOURNAL OF ADVANCES IN CHEMISTRY 7, no. 1 (2011): 1223–39. http://dx.doi.org/10.24297/jac.v7i1.974.

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The study represents the first report on the development of spectrophotometric methods for determination of ethamsylate (EST) in the presence of hydroquinone as an impurity and/or acidic degradation product. The proposed methods are based on the reaction of EST through it,s secondary amino group either with 1,2-naphthoquinone-4-sulphonate sodium (NQS) at pH 10.7 or 2,4-dinitrofluorobenzene (DNFB) at pH 9.3 to form orange and yellow colored reaction products peaking at 478 and 387 nm for methods (I) and (II), respectively. The different experimental parameters affecting the development and stab

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30

Zhang, Tingting, Wanting Yin, Bo Jin, Tong Li, and Chen Ma. "A reliable HPLC-DAD method for simultaneous determination of related substances in TBI-166 active pharmaceutical ingredient." Acta Chromatographica 32, no. 2 (2020): 80–85. http://dx.doi.org/10.1556/1326.2019.00517.

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A sensitive, stability-indicating reversed-phase high-performance liquid chromatography with diode array detection (HPLC–DAD) method has been developed for the determination of TBI-166 and its 10 kinds of related impurities. Chromatographic separation was achieved on a Kromasil ODS column (250 mm × 4.6 mm, 5 μm), with a gradient elution of the mobile phase system consisting of acetonitrile and 1% ammonium formate solution (with 0.2% formic acid). The flow rate was 1.0 mL/min, and the detection wavelength was set at 251 nm. The method was validated according to the International Conference on H

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31

Lacrok, Pauline M., Patrick N. Yat, and Edward G. Lovering. "Liquid Chromatographic Methods for Fluoxetine Hydrochloride, Its meta Isomer, and Related Compounds in Raw Materials." Journal of AOAC INTERNATIONAL 78, no. 2 (1995): 334–38. http://dx.doi.org/10.1093/jaoac/78.2.334.

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Abstract Liquid chromatographic (LC) methods were developed for assay of fluoxetine hydrochloride, its meta isomer, and 12 related compounds in drug raw materials. The method for assay and determination of the meta isomer requires an Exsil ODS-B column; a mobile phase consisting of tetrahydrofuran, acetonitrile, and buffer; a flow rate of 1 mL/min; and detection at 214 nm. The method for related compounds specifies a Spherisorb nitrile column; a mobile phase consisting of tetrahydrofuran, acetonitrile, and buffer; a flow rate of 1 mL/min; and detection at 214 nm. The limits of quantitation in

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32

Golembiovska, Оlena, Oleksii Voskoboinik, Galina Berest, Sergiy Kovalenko, and Liliya Logoyda. "Quality by design approach for simultaneous determination of original active pharmaceutical ingredient quinabut and its impurities by using HPLC. Message 1." Pharmacia 68, no. 1 (2021): 79–87. http://dx.doi.org/10.3897/pharmacia.68.e50704.

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Aim. The aim of study was to develop and validate a simple, highly robust (quality by design (QbD) approach), precise and accurate method using high performance liquid chromatography for the simultaneous determination of original active pharmaceutical ingredient Quinabut and its impurities. Materials and methods. Experiments were performed on a Shimadzu LC-20 Prominence HPLC separation module, equipped with a quaternary gradient pump, temperature controlled column heater, sampler manager and diode array detector and LC-20 Chemstation for data analysis (Shimadzu Corporation, Japan). Same softwa

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Hauck, Bernd, Samuel Murphy, Xingge Lui, Olga Zelenaia, Katherine A. High, and J. Fraser Wright. "Trace Capsid DNA Impurities in AAV2 Vectors Are Not Transcribed and Are Unlikely To Contribute to Capsid Peptide-MHC Class I Complexes." Blood 110, no. 11 (2007): 3736. http://dx.doi.org/10.1182/blood.v110.11.3736.3736.

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Abstract Cytotoxic T cell responses directed against adeno-associated virus (AAV) capsid may limit long-term therapeutic gene expression in human subjects following AAV vector administration to liver (Manno et al, 2006, Nature Med). Possible mechanisms for presentation of AAV capsid-derived peptide epitopes on the surface of transduced hepatocytes include: degradation of the pre-formed capsid component of the vector and presentation of capsid-derived peptides on the surface of transduced cells; and transcription and translation of trace levels of AAV capsid DNA (an impurity), resulting in cell

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Sibinovic, Predrag, Andreja Smelcerovic, Radosav Palic, Sinisa Djordjevic, and Valentina Marinkovic. "Ruggedness testing of an HPLC method for the determination of ciprofloxacin." Journal of the Serbian Chemical Society 70, no. 7 (2005): 979–86. http://dx.doi.org/10.2298/jsc0507979s.

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The possibility of optimization of an HPLC method for the determinations of ciprofloxacin and ciprofloxacin impurity C was investigated according to the British Pharmacopoeia, using ruggedness testing. Four factors were selected to be tested in this ruggedness test (temperature of the column, volume of acetonitrile in the mobile phase, volume of the aqueous phase in the mobile phase and pH of the aqueous phase in the mobile phase). Seven responses were determined in each design experiment: retention times, peak heights, peak widths, number of theoretical plates, peak areas, peak areas RSD (%)

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AL-TAHER, FADWA, and BORIS NEMZER. "Determination and Quantitation of Residual Solvents in Natural Food Ingredients Using a Static Headspace Gas Chromatography with Flame Ionization Detection and Mass Spectrometric Detection Method." Journal of Food Protection 81, no. 10 (2018): 1573–81. http://dx.doi.org/10.4315/0362-028x.jfp-18-142.

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ABSTRACT The determination of residual solvents is critical for quality control in food production and manufacturing processes. A gas chromatographic and mass spectrometric detection (MSD) method was developed and validated to complement the static headspace flame ionization detection (FID) technique for identification, confirmation, and quantitation of solvent residues in botanicals, using Coffeeberry extract and pomegranate powder as test samples. Relative standard deviations (RSDs) of less than 12% were obtained for residual solvents in water and dimethyl sulfoxide. Coffeeberry extract supp

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Reddy, C. Purushotham, G. Venkateswara Rao, K. Ramakrishna, and K. M. V. Narayana Rao. "Method Development and Validation for Quantification of Potential Genotoxic Impurity, PyCl in Lansoprazole Hydrochloride using Liquid Chromatography Combined with Mass Spectrometry." Asian Journal of Chemistry 33, no. 5 (2021): 1165–68. http://dx.doi.org/10.14233/ajchem.2021.23135.

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A sensitive and robust high performance liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) method was developed and validated for the determination of potential genotoxic impurity (PGI), 2-(chloromethyl)-3-methyl-4-(2,2,2-trifluoroethoxy)-pyridine hydrochloride (PyCl) in lansoprazole as per ICH Q2 guideline. In this method, PyCl and lansoprazole were well-separated from each other on Acquity UPLC BEH-C18 column (50 × 4.6 mm × 1.7 μ) in a gradient elution mode with the mobile phase consisting of 0.1% formic acid in water (mobile phase-A) and acetonitrile (mobile phase-B) at

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Zou, Liang, Lili Sun, Hui Zhang, Wenkai Hui, Qiaogen Zou, and Zheying Zhu. "Identification, Characterization, and Quantification of Impurities of Safinamide Mesilate: Process-Related Impurities and Degradation Products." Journal of AOAC INTERNATIONAL 100, no. 4 (2017): 1029–37. http://dx.doi.org/10.5740/jaoacint.16-0218.

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Abstract The characterization of process-related impurities and degradation products of safinamide mesilate (SAFM) in bulk drug and a stability-indicating HPLC method for the separation and quantification of all the impurities were investigated. Four process-related impurities (Imp-B, Imp-C, Imp-D, and Imp-E) were found in the SAFM bulk drug. Five degradation products (Imp-A, Imp-C, Imp-D, Imp-E, and Imp-F) were observed in SAFM under oxidative conditions. Imp-C, Imp-D, and Imp-E were also degradation products and process-related impurities. Remarkably, one new compound, identified as (S)-2-[4

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Kamdar, Gulzar, and Sonal Desai. "Optimization and Validation of HPTLC Method for Estimation of Ulipristal Acetate in Presence of Its Forced Degradation Products." Journal of Chromatographic Science 58, no. 5 (2020): 427–32. http://dx.doi.org/10.1093/chromsci/bmaa002.

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Abstract Ulipristal acetate (UPA) is used as emergency contraceptive and for uterine fibroids. No validated method has been reported to estimate UPA in presence of its degradation products. Therefore it is mandatory to develop method which can accurately measure it in presence of impurity. A simple and sensitive high-performance thin-layer chromatography (HPTLC) method was developed for the estimation of UPA. Pre-coated silica gel 60F254 TLC plates were as stationary phase and ethyl acetate:toluene:glacial acetic acid (4:7:0.3, v/v/v) was used as mobile phase. Drug was subjected to acid and al

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Choudhari, Vishnu P., and Anna Pratima G. Nikalje. "Development and Validation of Stability Indicating LC-PDA Method for Mycophenolate Mofetil in Presence of Mycophenolic Acid and Its Application for Degradation Kinetics and pH Profile Study." Advances in Chemistry 2014 (June 30, 2014): 1–9. http://dx.doi.org/10.1155/2014/719385.

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Factorial design tool applied for development of isocratic reversed-phase stability-indicating HPLC method for the analysis of mycophenolate mofetil (MMF) and its degradation products. MMF stress degradation products mycophenolate acid (MPA) and DP3 (USP impurity H) were isolated and used for quantitation. Separation achieved on a Symmetry C18 (250 mm × 4.6 mm, 5.0 μ) column using a methanol: acetate buffer (75 : 25 v/v), pH 6.0 (adjusted with acetic acid), at 0.5 mL flow rate, column maintained at 55°C, and data integrated at 251 nm. MMF is subjected to hydrolysis, oxidation, heat degradation

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Mischenko, E. S., J. S. Lazaryan, and A. Jh Lazaryan. "Use of High Performance Liquid Chromatography in the Analysis of a New Substance VMA-10-18." Drug development & registration 10, no. 3 (2021): 76–81. http://dx.doi.org/10.33380/2305-2066-2021-10-3-76-81.

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Introduction. Quinazoline derivatives have a wide range of pharmacological properties, which makes this group quite unique among other classes of heterocyclic compounds. Substance VMA-10-18, which has cerebrovasodilating, antidepressant, anxiolytic and nootropic properties, may become a promising new drug. In this regard, an urgent task is to develop methods for standardizing this substance.Aim. Development of a method for the quantitation of related impurities of a new biologically active substance VMA-10-18 (Quinazophene) by HPLC with subsequent statistical processing of the results.Material

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Rajana, Nagaraju, Kaviaraj M. Yarbagi, K. Balakumaran, et al. "An Orthogonal Approach for Determination of Acetamide Content in Pharmaceutical Drug Substance and Base-Contaminated Acetonitrile by GC and GC-MS External Method." Journal of Chromatographic Science 57, no. 9 (2019): 769–77. http://dx.doi.org/10.1093/chromsci/bmz077.

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Abstract Acetamide is a potential genotoxic impurity; it should control in drug substance based on daily dosage level. It forms from base-contaminated acetonitrile and by-product of some drug substances. The available methods for acetamide in drug substance and water samples were determined by GC-MS using internal standard with critical procedures. These developed and validated methods can assist in evaluating the reaction between acetonitrile and different bases and also determine trace level acetamide in drug substances. The method development was initiated with DB-624, 30 m, 0.32 width and

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Heleno Ferreira, Raquel Balestri, Jonathaline Apollo Duarte, Flávio Dias Ferreira, et al. "Biological Safety Studies and Simultaneous Determination of Linagliptin and Synthetic Impurities by LC-PDA." Journal of Analytical Methods in Chemistry 2019 (March 3, 2019): 1–10. http://dx.doi.org/10.1155/2019/7534609.

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A stability-indicating LC method was developed for quantification of linagliptin (LGT) and three synthetic impurities. The method utilizes a Thermo Scientific® RP-8 column (100 mm × 4.6 mm; 5 μm) with the PDA detector for quantitation of impurities. A mixture of 0.1% formic acid with pH 3.5 (A) and acetonitrile (B) was used as the mobile phase at a flow rate of 0.6 mL·min−1 with gradient elution. The percentage of mobile phase B increases from 30% to 70% over 5 min and decreases from 70% to 30% between 5 and 8 min. The method was validated according to International Council for Harmonization (

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Athavia, Birva A., Zarna R. Dedania, Ronak R. Dedania, S. M. Vijayendra Swamy, and Chetana B. Prajapati. "STABILITY INDICATING HPLC METHOD FOR DETERMINATION OF VILAZODONE HYDROCHLORIDE." International Journal of Current Pharmaceutical Research 9, no. 4 (2017): 123. http://dx.doi.org/10.22159/ijcpr.2017v9i4.20975.

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Objective: The aim and objective of this study was to develop and validate Stability Indicating HPLC method for determination of Vilazodone Hydrochloride.Methods: The method was carried out on a Phenomenex, C18 (250x4.6 mm, 5 µm) Column using a mixture of Acetonitrile: Water (50:50v/v), pH adjusted to 3.3 with Glacial Acetic Acid for separation. The flow rate was adjusted at 1 ml/min and Detection was carried out at 240 nm.Results: The retention time of vilazodone hydrochloride was found to be 2.3 min. The calibration curve was found to be linear in the range 25-75µg/ml with a correlation coef

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SHAIKH, JALIL K., MAZAHAR FAROOQUI, and UMMUL KHAIR ASEMA SYED. "Quality by Design Approach for Development and Validation of Stability Indicating RP-HPLC Method for Fosaprepitant Dimeglumine." Asian Journal of Chemistry 32, no. 9 (2020): 2158–64. http://dx.doi.org/10.14233/ajchem.2020.22758.

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Quality by design approach has been used to develop simple, rapid, sensitive gradient RP-HPLC stability indicating method for fosaprepitant dimeglumine and its related impurities. The chromatographic method has been developed by using symmetry shield RP-18 (250 mm × 4.6 mm; 5 μm) column maintained at column temperature of 20 ºC. The mobile phase-A consisted of water and acetonitrile (800:200, v/v), added 2 mL of orthophosphoric acid and 0.17 g of tetrabutylammonium hydrogen sulphate. The mobile phase-B consisted of water and acetonitrile (200:800, v/v), added 2 mL of orthophosphoric acid and 0

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Takale, Nilesh, Neelakandan Kaliyaperumal, Gopal Krishnan, Mannathusamy Mannathusamy, and Raja Rajan Govindasamy. "Stability Indicating RP-HPLC Method Development for Related Substances of Anti-histamine Promethazine hydrochloride and its Validation study." Oriental Journal Of Chemistry 36, no. 05 (2020): 889–96. http://dx.doi.org/10.13005/ojc/360513.

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A smooth, specific, precise, and accurate high-performance reverse phase (RP-HPLC) method for determining related substances in antihistamine Promethazine Hydrochloride (PMZ∙HCI) has been recorded. The RP-HPLC system is developed and tested in compliance with recommendations Q2(R1) of the International Council for Harmonization (ICH). Column 5m and reverse step with linear gradient elution is accomplished in Symmetry Shield RP8 (4.6 mm x 150 mm). Mobile phase A is 3.4% in the 7.0 pH water, modified to dilute potassium hydroxide solution. In contrast, the 60:40 mixture of acetonitrile and metha

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Belal, Tarek S., Rim S. Haggag, and Rasha A. Shaalan. "Selective and Stability-Indicating Methods for the Simultaneous Determination of Mexiletine Hydrochloride and/or Its Related Substance: 2,6-Dimethylphenol." Journal of AOAC INTERNATIONAL 91, no. 4 (2008): 720–30. http://dx.doi.org/10.1093/jaoac/91.4.720.

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Abstract Four simple, rapid, sensitive, and selective analytical procedures were developed for determination of mexiletine hydrochloride (MX) and/or its related substance: 2,6-dimethylphenol (DMP). The latter is a synthetic impurity for which a maximum pharmacopeial limit is defined. The first method depends on derivative-ratio spectrophotometry, for which the first-derivative signals of the ratio spectra at 259 nm ( = 3 nm) are selected for the determination of MX. The second method is based on the spectrofluorometric measurement of MX in alkaline solution in the presence of 15 mM sodium dode

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Rossouw, C. J., P. S. Turner, T. J. White, and A. J. O’Connor. "Quantitative ALCHEMI With Error Analysis." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 2 (1990): 468–69. http://dx.doi.org/10.1017/s0424820100135940.

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The ALCHEMI technique for determining the site distribution fi of an impurity element x on host element lattice sites i is well known: Changes in x-ray emission from host atoms i and impurity x with crystal orientation ARE monitored under strong planar or axial diffraction conditions, and fi derived via a ratio method. However analysis involving count ratios (and ratios of ratios) leads to severe error amplification. Neglect of delocalization leads to further error. To overcome these inherent errors in the standard ALCHEMI method, we make the single assumption that the impurity count Nx may be

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Caspi, Daniel D., and Fredrik L. Nordstrom. "Quantitative Impurity Rejection Analysis for Crystallization." Organic Process Research & Development 22, no. 7 (2018): 856–61. http://dx.doi.org/10.1021/acs.oprd.8b00143.

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Salleh, Faiz, and Hiroya Ikeda. "Influence of Impurity Band on Seebeck Coefficient in Heavily-Doped Si." Advanced Materials Research 222 (April 2011): 197–200. http://dx.doi.org/10.4028/www.scientific.net/amr.222.197.

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We calculated the Seebeck coefficient of heavily-doped Si based on theoretical models of impurity-band formation, ionization-energy shift and conduction-band tailing. The impurity band was described by using two kinds of band-width definitions and it was found that the calculated Seebeck coefficient strongly depended on the impurity-band definition. In the high impurity-concentration region, the Seebeck coefficient decreased with increasing impurity concentration, and with a peak around 1×1019 cm-3. This result was qualitatively in good agreement with the experimental result, while there was q

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Tang, Zhengmin, Hu Deng, Quancheng Liu, Jin Guo та Liping Shang. "Quantitative analysis of low-concentration α-HMX based on terahertz spectroscopy". Analytical Methods 12, № 47 (2020): 5684–90. http://dx.doi.org/10.1039/d0ay01583k.

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