Stability Indicating RP-UPLC Method for Simultaneous Estimation of Rabeprazole Sodium and Mosapride Citrate in Tablet Dosage form

RP- UPLC method was developed and validated for the simultaneous determination of Rabeprazole sodium and Mosapride citrate in tablet dosage form. The separation was achieved on a BEH C18 (50mm × 2.1mm× 1.7µm) column using mobile phase of Ammonium acetate buffer: Acetonitrile (60:40% v/v). The flow rate was 0.4 ml/min and detection was carried out at 270nm and column oven 35ºC. Rabeprazole sodium and Mosapride citrate was subjected to stress condition including Acidic, Alkaline, Oxidation, Photolysis and Thermal degradation. This method was validated as per ICH (Q2R1) guideline.

Development and validation of a new stability indicating RP-UFLC method for the estimation of Bosentan

A new stability-indicating RP-UFLC method has been developed for the estimation of Bosentan in pharmaceutical dosage forms and the method was validated. Bosentan is used to lower the high blood pressure in lungs (pulmonary arterial hypertension). Bosentan acts by blocking the actions of endothelin -1and thereby lowers the blood pressure. Mobile phase mixture consisting of sodium acetate (pH 5.0) buffer solution and acetonitrile (50: 50 v/v) with flow rate 0.7 mL/min were the optimized chromatographic conditions (Detection wavelength 254 nm) for the present study. Linearity was observed in the concentration range of 0.1–100 μg/mL (R2 = 0.9998) with regression equation y = 126698 x – 392.49. The LOQ was found to be 0.08964 µg/mL and the LOD was found to be 0.02913 µg/mL. Stress degradation studies such as acidic, alkaline, oxidation, photolysis and thermal degradations were performed by exposing Bosentan and finally the proposed method was validated as per ICH guidelines. The assay of Bosentan was conducted by applying the proposed method to the marketed formulations. The proposed method is simple, specific, precise, and accurate and can be applied for the estimation of pharmaceutical formulations.

A new stability indicating ultra-fast liquid chromatographic (RP-UFLC) method for the quantification of Nilotinib – A drug for blood cancer

Nilotinib hydrochloride monohydrate is a tyrosine kinase inhibitor approved for the treatment of chronic myelogenous leukemia. A new stability indicating ultra-fast liquid chromatographic (RP-UFLC) method was developed for the quantification of Nilotinib and validated. Mobile phase consisting of a mixture of sodium acetate (pH 5.0): acetonitrile (40: 60, v/v) was used with flow rate 0.8 mL/min (UV detection at 254 nm) for the chromatographic study. Nilotinib obeys Beer-Lambert’s law over the concentration range of 0.2-80 μg/mL (R2 = 0.9999) with linear regression equation y = 175336x +20675. The LOQ was found to be 0.1897 μg/mL and the LOD was found to be 0.0619 μg/mL. Forced degradation studies were performed such as acidic, alkaline, oxidation and thermal degradations and the method was validated as per ICH guidelines.

Characterization of Natural and Alkaline-Oxidized Proanthocyanidins in Plant Extracts by Ultrahigh-Resolution UHPLC-MS/MS

In this study, we analyzed the proanthocyanidin (PA) composition of 55 plant extracts before and after alkaline oxidation by ultrahigh-resolution UHPLC-MS/MS. We characterized the natural PA structures in detail and studied the sophisticated changes in the modified PA structures and the typical patterns and models of reactions within different PA classes due to the oxidation. The natural PAs were A- and B-type PCs, PDs and PC/PD mixtures. In addition, we detected galloylated PAs. B-type PCs in different plant extracts were rather stable and showed no or minor modification due to the alkaline oxidation. For some samples, we detected the intramolecular reactions of PCs producing A-type ether linkages. A-type PCs were also rather stable with no or minor modification, but in some plants, the formation of additional ether linkages was detected. PAs containing PD units were more reactive. After alkaline oxidation, these PAs or their oxidation products were no longer detected by MS even though a different type and/or delayed PA hump was still detected by UV at 280 nm. Galloylated PAs were rather stable under alkaline oxidation if they were PC-based, but we detected the intramolecular conversion from B-type to A-type. Galloylated PDs were more reactive and reacted similarly to nongalloylated PDs.

RP-UPLC Stability Indicating Assay Method for Simultaneous Estimation of Dextromethorphan Hydrobromide and Chlorpheniramine Maleate in Tablet Dosage Form

RP-UPLC method was developed and validated for the determination of chlorpheniramine maleate and dextromethorphan hydrobromide in tablet dosage form. Reverse phase waters acquity UPLC BEH C18 (50 mm × 2.1 mm, 1.7 μm) column using isocratic mobile phase of 0.5 mL 0.1% TFA (trifluroacetic acid) in H2O:CH3CN (70:30 %v/v). The flow rate was 0.2 mL/min and 252 nm wavelength use for detection on PDA detector. The retention time of chlorpheniramine maleate was 1.2 min and 2.2 min for dextromethorphan hydrobromide. Chlorpheniramine maleate and dextromethorphan hydrobromide was subjected to stress conditions including acidic, alkaline, oxidation, photolysis and thermal degradation. The method was validated as per ICH guideline with respect to samples to specificity, precision, accuracy, linearity and robustness.