Comprehensive comparative study of eco-friendly Univariate and multivariate methodological approaches on processing multi-component formulation quality
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
Authors: Fayez, Yasmin M.; Michael, Adel M.; Monir, Hany H.; Lotfy, Hayam M.; Nessim, Christine K.
Abstract
This study presents comprehensive comparative study of different eco-friendly spectrophotometric approaches without any sample treatment on processing quaternary mixture of sulphadimidine sodium (SDS), sulphaquinoxaline sodium (SQS), diaveridine (DVD) and vitamin K-3 (VTK3). The different univariate complementary resolutions according to the response used for the assay of the cited drugs after applying the processing steps were implemented using successive ratio subtraction coupled with constant multiplication (SRS-CM), absorbance subtraction (AS) and amplitude modulation (AM). On the other hand, multivariate spectrophotometric models were developed and validated for simultaneous determination of the cited mixture. Resolution was accomplished by using two multivariate calibration greener models, including principal component regression (PCR) and partial least-squares (PLS). The proposed approaches are considered environmentally friendly since they use only water as reagent, which is cheap and safe for the operator. The calibration graphs are linear over the range of (4.0-13.0) mu g/mL for (SDS), (1.0-10.0) mu g/mL for (SQS), (1.0-11.0) mu g/mL for (DVD) and (1.0-8.0) mu g/mL for (VTK3). Specificity of the applied procedures was assessed by analyzing the laboratory-prepared mixtures and their combined dosage form. The outcomes of the developed methods were statistically compared with those of the official and reported methods; using Student's t-test and F-test, showing no significant difference. The proposed methodologies can be used for the routine analysis of the cited drugs in quality control laboratories. (c) 2020 Elsevier B.V. All rights reserved.
Comparison of the retention of basic compounds in anionic and cationic microemulsion electrokinetic chromatographic systems
MICROCHEMICAL JOURNAL
Authors: Fernandez-Pumarega, Alejandro; Olmo, Laura; Amezqueta, Susana; Fuguet, Elisabet; Roses, Marti
Abstract
Retention of ionizable bases in microemulsion electrokinetic chromatography (MEEKC) has been studied using two different systems with anionic and cationic microemulsions. Microemulsion pseudostationary phase is composed of heptane (oil), 1-butanol (cosurfactant) and sodium dodecyl sulfate (SDS, anionic system) or tetradecyltrimethylammonium bromide (TTAB, cationic system) as surfactant. In contrast with micellar electrokinetic chromatography (MEKC) where the retention of neutral compounds is very different in the two micellar pseudostationary phases (SDS and TTAB, respectively); in MEEKC, neutral compounds present very similar retention factor (k) values in SDS and TTAB microemulsion pseudostationary phases. However, the k vs. pH profiles of protonable bases are very different in the two MEEKC systems. In TTAB system, retention increases with pH because of neutralization of the protonated base and partition of the unionized form into the microemulsion. However, a reversed trend is observed in SDS system. Retention decreases with pH because of the formation of an ionic pair between the protonated base and the anionic SDS, much more retained than the unionized base. Thus, it is demonstrated that the two systems behave very similar in the retention of neutral bases, but completely different for retention of protonated bases.