Quantitation of irbesartan and major proteins in human plasma by mass spectrometry with time-of-flight analyzer

Selective and validated kinetic spectrophotometric method for the determination of irbesartan in pure and pharmaceutical formulations

A novel-coupling reagent is used for the simple and sensitive kinetic spectrophotometric determination of irbesartan (IRB) in pure or pharmaceutical formulations. The method utilizes an oxidative coupling reaction based on oxidation of 3-methyl-2-benzothiazolinone hydrazone hydrochloride monohydrate (MBTH) with Ce(IV) in 2% sulfuric acid medium, followed by coupling the produced electrophilic intermediate (diazonium salt of the reagent) with IRB to give greenish-blue colored product (1:1, stoichiometry) having maximum absorption at 629nm and the colored species is stable for more than 1h. The initial rate and fixed time (at 35min) methods are adopted for determination of IRB concentration. The linearity is in the ranges of 5.0-40.0μg/mL and 2.0-45.0μg/mL and the limit of detection is 0.46 and 0.40μg/mL for initial rate and fixed time methods, respectively. Molar absorptivity for the method was found to be 1.50×10⁴L/molcm. The validated kinetic methods can be successfully applied to the analysis of IRB in bulk and tablet dosage form and in the routine quality control analysis. The percentage recoveries were above 100% for both methods. The excipients did not interfere in the analysis.

Application of MALDI-TOF/TOF-MS for relative quantitation of α- and β-Asp7 isoforms of amyloid-β peptide

It is known that aspartic acid isomerization process plays a role in aging processes and may be used as a marker for aging of natural materials. As for Alzheimer's disease, the most abundant modification in the peptide profile is the aspartate isomerization of amyloid-β. Liquid chromatography-electrospray ionization-mass spectrometry/mass spectrometry-based approaches with Collision Induced Dissociation (CID) or Electron Capture Dissociation (ECD) fragmentation provide a good and precise method for the relative quantitation of iso- to normal amyloid-β peptides but require additional time consuming steps. In this study, MALDI-TOF/TOF-matrix-assisted laser desorption ionization time-of-flight tandem mass spectrometry (MS) method was developed as a high-throughput approach for the relative quantitation of the isomerized form of the amyloid-β peptide.

A validated stability-indicating liquid chromatographic method for determination of process related impurities and degradation behavior of Irbesartan in solid oral dosage

The present work describes the development and validation of a stability-indicating RP-HPLC method for the estimation of degradation and process related impurities of Irbesartan, namely Impurity-1, Impurity-2, Impurity-3 and Impurity-4. The developed LC method was validated with respect to specificity, limit of detection and quantification, linearity, precision, accuracy and robustness. The chromatographic separation was achieved on Hypersil Octadecylsilyl (4.6 mm × 150 mm, 3 μm) column by using mobile phase containing a gradient mixture of solvent A (0.55% v/v ortho-phosphoric acid, pH adjusted to 3.2 with triethyl amine) and B (95:5 v/v mixture of acetonitrile and solvent A) at a flow rate of 1.2 mL/min. The detection was carried out at a wavelength of 220 nm. During method validation parameter such as precision, linearity, accuracy, specificity, limit of detection and quantification were evaluated, which remained within acceptable limits. HPLC analytical method is linear, accurate, precise, robust and specific, being able to separate the main drug from its degradation products. The degradation products were well-resolved from the main peak and its impurities, thus proving the stability-indicating power of the method. The method is stability-indicating in nature and can be used for routine analysis of production samples and to check the stability of the Irbesartan HCl tablets.

Analysis of Sartans: a review

The risk of cardiovascular diseases is closely related to hypertension, high cholesterol levels, and diabetes. When these risk factors appear together they are referred to as a metabolic syndrome. In the treatment of cardiovascular diseases, a combination of antihypertensive, hypolipemiant, and antidiabetic drugs is often applied. Diuretics (chlortalidone, hydrochlorothiazide, etc.) and angiotensin II receptors antagonist (sartans) are used to control hypertension, whereas statins (fluvastatin, simvastatin, etc.) are used to reduce cholesterol levels. This review is concerned with methods for the analysis of sartans in various matrices, such as pharmaceutical formulations, environmental and biological samples, and discusses the current status of stability studies of sartans . It also presents analytical methods for the simultaneous determination of sartans, diuretics, and statins.