Aliskiren
Hassan, S. A., E. S. Elzanfaly, M. Y. Salem, and B. A. El-Zeany,
"Mean centering of double divisor ratio spectra, a novel spectrophotometric method for analysis of ternary mixtures",
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, vol. 153: Elsevier, pp. 132-142, 2016.
AbstractA novel spectrophotometric methodwas developed for determination of ternary mixtureswithout previous separation, showing significant advantages over conventionalmethods. The newmethod is based onmean centering of double divisor ratio spectra. The mathematical explanation of the procedure is illustrated. The method was evaluated by determination of model ternary mixture and by the determination of Amlodipine (AML), Aliskiren (ALI) and Hydrochlorothiazide (HCT) in laboratory prepared mixtures and in a commercial pharmaceutical preparation. For proper presentation of the advantages and applicability of the new method, a comparative study was established between the new mean centering of double divisor ratio spectra (MCDD) and two similar methods used for analysis of ternary mixtures, namely mean centering (MC) and double divisor of ratio spectraderivative spectrophotometry (DDRS-DS). The methodwas also comparedwith a reported one for analysis of the pharmaceutical preparation. The method was validated according to the ICH guidelines and accuracy, precision, repeatability and robustness were found to be within the acceptable limits.
Elzanfaly, E. S., S. A. Hassan, M. Y. Salem, and B. A. El-Zeany,
"Continuous Wavelet Transform, a powerful alternative to Derivative Spectrophotometry in analysis of binary and ternary mixtures: A comparative study",
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, vol. 151: Elsevier, pp. 945-955, 2015.
AbstractA comparative study was established between two signal processing techniques showing the theoretical
algorithm for each method and making a comparison between them to indicate the advantages and
limitations. The methods under study are Numerical Differentiation (ND) and Continuous Wavelet
Transform (CWT). These methods were studied as spectrophotometric resolution tools for simultaneous
analysis of binary and ternary mixtures. To present the comparison, the two methods were applied for
the resolution of Bisoprolol (BIS) and Hydrochlorothiazide (HCT) in their binary mixture and for the
analysis of Amlodipine (AML), Aliskiren (ALI) and Hydrochlorothiazide (HCT) as an example for ternary
mixtures. By comparing the results in laboratory prepared mixtures, it was proven that CWT technique
is more efficient and advantageous in analysis of mixtures with severe overlapped spectra than ND.
The CWT was applied for quantitative determination of the drugs in their pharmaceutical formulations
and validated according to the ICH guidelines where accuracy, precision, repeatability and robustness
were found to be within the acceptable limit.
