Spectral analysis of overlapped absorption bands of binary mixtures—an application on combination of pseudoephedrine sulphate and loratadine mixture

Abstract

Background: Simple, specific, accurate, and precise spectrophotometric methods are progressed and validated for concurrent analysis of pseudoephedrine sulphate (PSE) and loratadine (LOR) in their combined dosage form depending on spectral analysis procedures. In this binary mixture, pseudoephedrine (PSE) could be determined by using its resolved spectrum of zero-order absorption at 256.8 nm after subtraction of the spectrum of LOR, and also it could be determined in existence of the spectrum of LOR by different methods including absorption correction method (AC) at 256.8 nm and 280 nm, dual wavelength method (DW) at 254 nm and 273 nm, induced dual-wavelength method (IDW) at 230 nm and 263 nm, and ratio difference method (RD) at 256.8 nm and 270 nm. Loratadine (LOR) in the binary mixture could be determined either by direct analysis at 280 nm without any contribution from the spectrum of PSE or through its recovered spectrum of zero-order absorption via constant multiplication method (CM) using plateau region (277-326 nm). Also, concurrent determination for PSE and LOR in their overlapped binary mixture could be achieved by applying induced amplitude modulation (IAM) method. Results: Specificity of the proposed spectrophotometric methods was examined by the analysis of prepared mixtures in laboratory and was applied successfully for pharmaceutical dosage form analysis which has the cited drugs without additive contribution. The proposed spectrophotometric methods were also validated as per the guidelines of ICH. Statistical comparison was performed between the obtained results with those from the official methods of the cited drugs, using one-way ANOVA, F test, and Student's t test, and the results exhibit insignificant difference concerning precision and accuracy. Conclusions: The previously proposed spectrophotometric methods could be easily used accurately and precisely for simultaneous determination of the studied binary mixture with simple manipulation procedures.

Sustainable spectrophotometric determination of antihypertensive medicines reducing COVID-19 risk via paired wavelength data processing technique - Assessment of purity, greenness and whiteness

“…Mathematical spectrophotometric methods using built in spectrophotometer's software are now being utilized more frequently for evaluation of drugs in pharmaceutical formulations ( Obaydo et al, 2021 ; Lotfy and Saleh, 2016 ; Saleh et al, 2022 ; Rostom et al, 2021 , 2022 ; Lotfy and Hagazy, 2012 ; Lotfy and Omran, 2018 ; Lotfy et al, 2014 , 2019 , 2020a , 2020b , 2020c , 2021 , 2022 ; Ahmed and Lotfy, 2021 , 2022 ; Samir et al, 2014 ; Obaydo and Sakur, 2019 ; Obaydo and Alhaj Sakur, 2019 ; Al Zakri et al, 2019 ; Darweish et al, 2022 ) as well as the recently developed approaches based on absorptivity centering ( Lotfy et al, 2020a , 2020c ; Lotfy and Omran, 2018 ; Obaydo et al, 2021 ) owing to their inherent benefits such as simplicity, accuracy, reduction of expensive reagents consumption and eschewing time consuming or special software utilization.…”