Simultaneous Estimation of Nebivolol Hydrochloride and Valsartan using RP HPLC

Quality by design approach for development and validation of a RP-HPLC method for simultaneous estimation of xipamide and valsartan in human plasma

A new rapid, simple, and sensitive RP-HPLC method was carried out through applying Quality by Design approach for determination of xipamide and valsartan in Human plasma. Fractional factorial design was used for screening of four independent factors: pH, flow rate, detection wavelength, and % of MeOH. Analysis of variance (ANOVA) confirmed that flow rate and % of MeOH were only significant. Chromatographic conditions optimization was carried out through using central composite design. Method analysis was performed using BDS Hypersil C8 column (250 × 4.6 mm, 5 μm) and an isocratic mobile phase of MeOH and 0.05 M KH₂PO₄ buffer pH 3 (64.5:35.5, v/v) at 1.2 mL/min flow rate with UV detection at 240 nm and 10 μL injection volume. According to FDA guidelines, the method was then validated for the determination of the two drugs clinically in human plasma in respect of future pharmacokinetic and bioequivalence simulation studies. The standard curve was linear in the concentration range of 5–100 µg/mL for both drugs, with a determination coefficient (R²) of 0.999. Also, the average recoveries lied within the range from 99.89 to 100.03%. The proposed method showed good predictability and robustness.

Retention behaviour of analytes in reversed phase high performance liquid chromatography - A review

The understanding of principles that drive the separation in reversed phase chromatography plays an important role in the prediction of elution of solutes in RP-HPLC. The separation in RP-HPLC is based on the principle of adsorption and partition. In addition, the log P value, pK_a value of the drug, chromatographic parameters like mobile phase pH, buffer concentration, organic modifier and mobile phase additives also influence the retention and selectivity of the analyte. It is found that hydrophobic, electrostatic, hydrogen bonding and other specific interactions between the stationary phase and the solutes along with the hydrophobicity of an analyte molecule (log P) modify the retention behaviour of the analytes. This article gives special attention to the influence of ionization and ion interaction on the separation of analytes. The drug molecules with different log P value containing protonated and deprotonated acids, bases and zwitterions are selected as examples and this article addresses various issues related to method development, relationships between analyte retention and mobile phase pH and pK_a value of the analyte. The advances in this regard, with highlights on topics such as mechanisms of retention and various factors that influence the retention behaviour of analytes is also updated with suitable examples.

Development and Validation of Bioanalytical Method for Determination of Nebivolol and Valsartan in Human Plasma by Using RP-HPLC

Aim

Nebivolol and valsartan are used in the treatment of hypertension. So, this study was conducted for the purpose of determining bioavailability/bioequivalence of nebivolol and valsartan in human plasma.

Materials and Methods

The chromatographic separation was performed on Symmetry C18 (150 × 4.6 mm, 5 μm) column using 0.01 N potassium dihydrogen phosphate (pH 3.0):acetonitrile (60:40) as the mobile phase at a flow rate of 1.0 mL/min and a detector wavelength of 280 nm. The retention times of nebivolol and valsartan in plasma were found to be 3.1 and 4.3 min, respectively.

Results

The method was validated statistically and by recovery studies. The linearity concentration was acceptable in the range of 0.5–10 ng/mL for nebivolol and 400–8000 ng/mL for valsartan. The lower limits of quantification were 0.5 ng/mL for nebivolol and 400 ng/mL for valsartan, which reached the levels of both drugs possibly found in human plasma. Per cent recoveries were obtained as 97.78% and 98.11% for nebivolol and valsartan, respectively.

Conclusion

The proposed method is simple, rapid, accurate, precise and gives us knowledge about the pharmacokinetics and therapeutic drug monitoring in clinical laboratories.

Simultaneous determination of Nebivolol hydrochloride and Valsartan in their binary mixture using different validated spectrophotometric methods

Five simple, sensitive, accurate and precise spectrophotometric methods were developed for the simultaneous determination of Nebivolol hydrochloride (NEB) and Valsartan (VAL) in their binary mixtures and in pharmaceutical dosage form. The methods included Ratio Difference, First Derivative ratio, Mean Centering of ratio spectra, Bivariate and H-Point Standard additions method. The calibration curves were linear over the concentration range of 10-70 μg/ml and 20-60 μg/ml for NEB and VAL, respectively for Ratio Difference and First Derivative ratio method and over the concentration range of 10-70 μg/ml and 10-60 μg/ml for NEB and VAL, respectively for Mean Centering of ratio spectra, Bivariate and H-Point Standard additions method. These methods were examined by analyzing synthetic mixtures of the studied drugs and they were utilized to determine the studied drugs in their commercial pharmaceutical preparation. All methods were validated as per ICH guidelines and accuracy, robustness, repeatability and precision were found to be within the acceptable limits. The results of the proposed methods were compared to the results of reported methods with no significant difference between them.

Valsartan

Valsartan is an antihypertensive drug which selectively inhibits angiotensin receptor type II. Generally, valsartan is available as film-coated tablets. This review summarizes thermal analysis, spectroscopy characteristics (UV, IR, MS, and NMR), polymorphism forms, impurities, and related compounds of valsartan. The methods of analysis of valsartan in pharmaceutical dosage forms and in biological fluids using spectrophotometer, CE, TLC, and HPLC methods are discussed in details. Both official and nonofficial methods are described. It is recommended to use LC-MS method for analyzing valsartan in complex matrices such as biological fluids and herbal preparations; in this case, MRM is preferred than SIM method.

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.