A stability-indicating liquid chromatographic method has been developed and validated for the determination of Diltiazem Hydrochloride(DTZ) together with its six related substances(Diltiazem sulphoxide,Imp-A,Imp-B,Imp...A stability-indicating liquid chromatographic method has been developed and validated for the determination of Diltiazem Hydrochloride(DTZ) together with its six related substances(Diltiazem sulphoxide,Imp-A,Imp-B,Imp-D,Imp-E,and Imp-F) in a laboratory mixture as well as in a novel tablet formulation developed in-house.Efficient chromatographic separation was achieved on a Hypersil BDS C_18(150 mm*4.6 mm,5.0 μm) with mobile phase containing 0.2% Triethylamine(TEA) in gradient combination with acetonitrile(ACN) at a flow rate of 1.0 mL/min and the eluent was monitored at 240 nm.In the developed method,the resolution of DTZ from any pair of impurities was found to be greater than 2.0.The test solution and related substances were found to be stable in the diluent for 24 h.The developed method resolved the drug from its known impurities,stated above,and also from additional impurities generated when the formulation was subjected to forced degradation;the mass balance was found close to 99.9%.Regression analyses indicate correlation coefficient value greater than 0.997 for DTZ and its six known impurities.The LOD for DTZ and the known impurities was at a level below 0.02%.The method has shown good,consistent recoveries for DTZ(99.8-101.2%) and also for its six known impurities(97.2-101.3%).The method was found to be accurate,precise,linear,specific,sensitive,rugged,robust,and stability-indicating.展开更多
Objective High performance liquid chromatography(HPLC)and liquid chromatography-mass spectrometry(LC/MS)methods were developed for the determination of ganciclovir and its related substances.Methods A Hypersil ODS2 co...Objective High performance liquid chromatography(HPLC)and liquid chromatography-mass spectrometry(LC/MS)methods were developed for the determination of ganciclovir and its related substances.Methods A Hypersil ODS2 column(4.6 mm×250 mm,5 μm)was used with a mobile phase of 0.02 M potassium dihydrogen phosphate buffer(pH 6.0)-methanol(92∶8)at a flow rate of 1.0 mL/min,and UV detector set at 254 nm was used for monitoring the eluents.Results The method was simple,rapid,selective and capable of separating all related substances at trace level with a detection limit of 0.04 μg/mL.It has been validated with respect to accuracy,precision,linearity,and limits of detection and quantification.The linearity range was 10.2-153.0 μg/mL with r=0.9998.The percentage recoveries ranged from 96.7% to 101.6%,and RSD was 1.24%-1.96%(n=5).Conclusion The method was found to be suitable not only for monitoring the reactions during the process development but also for quality control of ganciclovir.For identification of related substances,LC/MS was used.The mainly related substances of ganciclovir active pharmaceutical ingredients(API)were determined as guanine,(1,3-dioxolan-4-yl)methyl acetate,and diacetyl guanine.展开更多
HPLC-ESI MS/MS method for relative substances of Mevastatin was established.An Agilent C18 column 250×4.6mm;Mobile phase: acetonitrile-0.05% formic acid (70:30),flow rate 1.0 mL/min,and λ238 nm;MS and MS/MS spec...HPLC-ESI MS/MS method for relative substances of Mevastatin was established.An Agilent C18 column 250×4.6mm;Mobile phase: acetonitrile-0.05% formic acid (70:30),flow rate 1.0 mL/min,and λ238 nm;MS and MS/MS spectra of sample and relative substances were obtained,approximately speculated the structure of relative substances,providing useful information for study and quality control of Mevastatin.展开更多
文摘A stability-indicating liquid chromatographic method has been developed and validated for the determination of Diltiazem Hydrochloride(DTZ) together with its six related substances(Diltiazem sulphoxide,Imp-A,Imp-B,Imp-D,Imp-E,and Imp-F) in a laboratory mixture as well as in a novel tablet formulation developed in-house.Efficient chromatographic separation was achieved on a Hypersil BDS C_18(150 mm*4.6 mm,5.0 μm) with mobile phase containing 0.2% Triethylamine(TEA) in gradient combination with acetonitrile(ACN) at a flow rate of 1.0 mL/min and the eluent was monitored at 240 nm.In the developed method,the resolution of DTZ from any pair of impurities was found to be greater than 2.0.The test solution and related substances were found to be stable in the diluent for 24 h.The developed method resolved the drug from its known impurities,stated above,and also from additional impurities generated when the formulation was subjected to forced degradation;the mass balance was found close to 99.9%.Regression analyses indicate correlation coefficient value greater than 0.997 for DTZ and its six known impurities.The LOD for DTZ and the known impurities was at a level below 0.02%.The method has shown good,consistent recoveries for DTZ(99.8-101.2%) and also for its six known impurities(97.2-101.3%).The method was found to be accurate,precise,linear,specific,sensitive,rugged,robust,and stability-indicating.
文摘Objective High performance liquid chromatography(HPLC)and liquid chromatography-mass spectrometry(LC/MS)methods were developed for the determination of ganciclovir and its related substances.Methods A Hypersil ODS2 column(4.6 mm×250 mm,5 μm)was used with a mobile phase of 0.02 M potassium dihydrogen phosphate buffer(pH 6.0)-methanol(92∶8)at a flow rate of 1.0 mL/min,and UV detector set at 254 nm was used for monitoring the eluents.Results The method was simple,rapid,selective and capable of separating all related substances at trace level with a detection limit of 0.04 μg/mL.It has been validated with respect to accuracy,precision,linearity,and limits of detection and quantification.The linearity range was 10.2-153.0 μg/mL with r=0.9998.The percentage recoveries ranged from 96.7% to 101.6%,and RSD was 1.24%-1.96%(n=5).Conclusion The method was found to be suitable not only for monitoring the reactions during the process development but also for quality control of ganciclovir.For identification of related substances,LC/MS was used.The mainly related substances of ganciclovir active pharmaceutical ingredients(API)were determined as guanine,(1,3-dioxolan-4-yl)methyl acetate,and diacetyl guanine.
文摘HPLC-ESI MS/MS method for relative substances of Mevastatin was established.An Agilent C18 column 250×4.6mm;Mobile phase: acetonitrile-0.05% formic acid (70:30),flow rate 1.0 mL/min,and λ238 nm;MS and MS/MS spectra of sample and relative substances were obtained,approximately speculated the structure of relative substances,providing useful information for study and quality control of Mevastatin.
