Smart Stability-Indicating Spectrophotometric Methods for Determination of Binary Mixtures Without Prior Separation

Abstract

Ratio subtraction and isosbestic point methods are 2 innovating spectrophotometric methods used to determine vincamine in the presence of its acid degradation product and a mixture of cinnarizine (CN) and nicergoline (NIC). Linear correlations were obtained in the concentration range from 840 g/mL for vincamine (I), 622 g/mL for CN (II), and 636 g/mL for NIC (III), with mean accuracies 99.72 0.917 for I, 99.91 0.703 for II, and 99.58 0.847 and 99.83 1.039 for III. The ratio subtraction method was utilized for the analysis of laboratory-prepared mixtures containing different ratios of vincamine and its degradation product, and it was valid in the presence of up to 80 degradation product. CN and NIC in synthetic mixtures were analyzed by the 2 proposed methods with the total content of the mixture determined at their respective isosbestic points of 270.2 and 235.8 nm, and the content of CN was determined by the ratio subtraction method. The proposed method was validated and found to be suitable as a stability-indicating assay method for vincamine in pharmaceutical formulations. The standard addition technique was applied to validate the results and to ensure the specificity of the proposed methods.

Two smart spectrophotometric methods for simultaneous determination of Lisinopril and Hydrochlorothiazide in binary mixtures

“…The obtained constant is subtracted then the resulting spectra is multiplied by the divisor (Y') to isolate the original spectrum of X that can be determined by applying the linear regression equation of its calibration at its λ max . On the other hand drug (Y) can be determined by applying the linear regression equation of its calibration at λ max of the extended curve [50,52].…”

Recent Development in Ultraviolet Spectrophotometry Through the Last Decade (2006–2016): A Review

“…This recently developed smart ratio subtraction method (RSM) [36] could be applied for the determination of several drugs in their binary mixtures without prior separation and has been applied for the determination of certain drugs in the presence of their degradation product. It based on the extension of zero order absorption spectrum of one of the components where the constants was measured at the extended part.…”

Rp-HPLC and Chemometric Methods for the Determination of Two Anti-Diabetic Mixtures; Metformin Hydrochloride-Canagliflozin and Metformin Hydrochloride-Gliclazide in Their Pharmaceutical Formulation

“…Classical UV spectral measurement use is often limited due to the overlapping of spectral peaks unless prior separation and extraction are employed. Several UV spectrophotometric chemometric methods are used in the simultaneous analysis for resolving mixtures based on mathematical processing and manipulations of the absorption spectra [27][28][29][30][31][32][33][34], offering sometimes an alternative to chromatographic methods.…”

“…7). In this method, two parameters were studied and optimized to obtain good selectivity and high sensitivity: wavelength interval (Δλ) and divisor concentration [27,[31][32][33].…”