title: Evaluation of the efficiency of continuous wavelet transform as processing and preprocessing algorithm for resolution of overlapped signals in univariate and multivariate regression analyses; an application to ternary and quaternary mixtures.
abstract: Wavelets have been adapted for a vast number of signal-processing applications due to the amount of information that can be extracted from a signal. In this work, a comparative study on the efficiency of continuous wavelet transform (CWT) as a signal processing tool in univariate regression and a pre-processing tool in multivariate analysis using partial least square (CWT-PLS) was conducted. These were applied to complex spectral signals of ternary and quaternary mixtures. CWT-PLS method succeeded in the simultaneous determination of a quaternary mixture of drotaverine (DRO), caffeine (CAF), paracetamol (PAR) and p-aminophenol (PAP, the major impurity of paracetamol). While, the univariate CWT failed to simultaneously determine the quaternary mixture components and was able to determine only PAR and PAP, the ternary mixtures of DRO, CAF, and PAR and CAF, PAR, and PAP. During the calculations of CWT, different wavelet families were tested. The univariate CWT method was validated according to the ICH guidelines. While for the development of the CWT-PLS model a calibration set was prepared by means of an orthogonal experimental design and their absorption spectra were recorded and processed by CWT. The CWT-PLS model was constructed by regression between the wavelet coefficients and concentration matrices and validation was performed by both cross validation and external validation sets. Both methods were successfully applied for determination of the studied drugs in pharmaceutical formulations.
authors.affiliation: Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, 11562 Cairo, Egypt.
authors.forename: Maha A
authors.initials: MA
authors.lastname: Hegazy
authors.affiliation: Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, 11562 Cairo, Egypt; Pharmaceutical Analytical Chemistry Department, Faculty of Pharmaceutical Science and Pharmaceutical Industries, Future University, 12311, Cairo, Egypt.
authors.forename: Hayam M
authors.initials: HM
authors.lastname: Lotfy
authors.affiliation: Analytical Chemistry Department, Faculty of Pharmacy, British University in Egypt, 11837 El-Sherouk City, Egypt; Analytical Chemistry Department, Faculty of Pharmacy, Helwan University, Ein Helwan, 11795 Cairo, Egypt.
authors.forename: Shereen
authors.initials: S
authors.lastname: Mowaka
authors.affiliation: Analytical Chemistry Department, Faculty of Pharmacy, British University in Egypt, 11837 El-Sherouk City, Egypt. Electronic address: ekramhany84@yahoo.com.
authors.forename: Ekram Hany
authors.initials: EH
authors.lastname: Mohamed
mesh_terms: D000082:Acetaminophen / Q000032:analysis*; D000465:Algorithms; D000627:Aminophenols / Q000032:analysis*; D000700:Analgesics / Q000032:analysis*; D002110:Caffeine / Q000032:analysis*; D000697:Central Nervous System Stimulants / Q000032:analysis*; D016018:Least-Squares Analysis; D015999:Multivariate Analysis; D010208:Papaverine / Q000031:analogs & derivatives* / Q000032:analysis; D013053:Spectrophotometry / Q000379:methods; D058067:Wavelet Analysis
chemical_list: D000627:Aminophenols; D000700:Analgesics; D000697:Central Nervous System Stimulants; D000082:Acetaminophen; D002110:Caffeine; C005317:drotaverin; D010208:Papaverine; C026729:4-aminophenol
keywords: Caffeine; Continuous wavelet transform; Drotaverine; Para-amino phenol; Paracetamol; Quaternary mixtures