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RP-HPLC stability-indicating method for simultaneous determination of sodium valproate, methylparaben and propylparaben in oral solution

Elrefay Hisham, Ismaiel Omnia A., Hassan Wafaa S., Shalaby Abdalla, Fouad Ali

Acta Chromatographica

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2022

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Vol. 34, no. 2

203--209

EN

A new, sensitive, stability-indicating reversed-phase HPLC method was validated and applied for the simultaneous quantitation of sodium valproate and two paraben preservatives; methylparaben, and propylparaben in the liquid dosage form. Stability tests were carried out through exposure of the analyte's solution to stress conditions. Separation of the analytes was achieved on (waters) C18 Column (150 mm × 3.9 mm, 5 μm). A mixture of 0.05 M monobasic potassium phosphate pH 3.5 and acetonitrile (50:50; v/v) was applied at 1.5 ml/min flow rate and UV detection wavelength at 210 nm. The degradation products and the analytes were completely separated. The linearity was performed in the range of 50–150 % from a target concentration of 10 μg/ml propylparaben, 90 μg/ml methylparaben, and 2.88 mg/ml sodium valproate with a coefficient correlation (R2) 1.0 for methylparaben, propylparaben and sodium valproate. The validation results of the suggested method were in a good agreement with ICH guidelines. Application of the proposed method for analysis of liquid dosage forms was successfully carried out in the routine quality control process.

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Development of a stability-indicating HPLC method and a dissolution test for rivaroxaban dosage forms

Souri E., Mottaghi S., Zargarpoor M., Ahmadkhaniha R., Jalalizadeh H.

Acta Chromatographica

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2016

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Vol. 28, no. 3

347--361

EN

Rivaroxaban is an inhibitor of factor Xa, which is used as an oral anticoagulant for the prevention of thromboembolism. The objective of this study was to develop a stability-indicating high-performance liquid chromatographic method for the quantitative determination of rivaroxaban in pharmaceutical dosage forms. Rivaroxaban was subjected to acidic, basic, oxidative, photolytic, and thermal conditions for forced stress degradation studies. Considerable degradation was observed in all stress degradation tests. Rivaroxaban and its degradation products were separated on a Nova-Pak C8 column utilizing a mixture of acetonitrile and KH2PO4 50 mM (pH 3.0) (40:60, v/v) as the mobile phase, and the chromatogram was recorded at 270 nm using a general ultraviolet (UV) detector. The developed method was linear over the concentration range of 1–50 μg mL−1 showing acceptable within-day and between-day precision and accuracy values (CV <2% and Error <2%). The dissolution profile of rivaroxaban tablets was also studied in the presence of a surfactant using optimized conditions. The validated method was successfully used for the determination of rivaroxaban in dosage forms and also in dissolution medium indicating the specificity of the assay method.

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A validated stability indicating RP-HPLC method for valganciclovir, identification and characterization of forced degradation products of valganciclovir using LC-MS/MS

Sawant S., Barge V.

Acta Chromatographica

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2014

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Vol. 26, no. 1

29--42

EN

The objective of the present study was to report the stability of novel antiviral drug, valganciclovir based on the information obtained from forced degradation studies. Valganciclovir was subjected to forced hydrolytic (acidic, alkaline and neutral), oxidative, photolytic and thermal stress in accordance with the ICH guideline Q1A (R2). The drug showed labiality under only acidic and photoacidic conditions while it was stable to other stress conditions. Resolution of the drug and degradation products was achieved on a Hypersil Gold C-18 column (4.6 × 250 mm, 5 μm) utilizing acetonitrile (A) and potassium dihydrogen ortho phosphate buffer (pH 5.0; 0.01M) in the ratio of 5:95 (v/v) at a flow rate of 0.6 ml/min and at the detection wavelength 252 nm. The major acidic stress degradation product was characterized by LC-MS/MS and its fragmentation pathway was proposed. Validation of the LC-DAD method was carried out in accordance with ICH guideline. The method met all required criteria and was applied for analysis of commercially available tablets.

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Stress degradation of Ta2O5 films on silicon

Novkovski N., Atanassova E.

Prace Naukowe Instytutu Podstaw Elektrotechniki i Elektrotechnologii Politechniki Wrocławskiej. Konferencje

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2004

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Vol. 40, nr 15

16-19

EN

Degradation of interface and film properties during constant voltage and constant current stress of Ta2O5 films grown on silicon was studied. It was shown that the degradation consists of positive and negative charge trapping and thinning of the extremely thin silicon dioxide created between the Ta2O5 and the silicon substrate.