جستجوی مقالات مرتبط با کلیدواژه « pharmaceutical samples » در نشریات گروه « شیمی »

A novel, repeatable, and swift kinetic approach for determining alpha-lipoic acid (ALA) in sodium lauryl sulfate (SLS) micellar medium has been presented, and it has been connected to ALA determination in drug formulations. The approach is based on ALA inhibitory property. ALA (containing two sulfur atoms) forms a chelate with Hg2+, lowering the effective [Hg(II)], and ultimately, the Hg2+ catalyzed cyanide substitution rate from [Ru(CN)6]4- by nitroso-R-salt (N-R-salt). Fixed times of 5 and 10 minutes were chosen under optimal reaction conditions with [N-R-salt] = 0.45 mM, pH = 7.0 ± 0.02, Temp = 45 ± 0.2 °C, I = 0.1 M (NaClO4), [Ru(CN)64-] = 42.5 µM, [Hg+2] = 0.25 mM, and [SLS] = 8.5 mM to calculate the absorbance at 525 nm associated with the final substitution product [Ru(CN)5 N-R-salt]3-. ALA's inhibiting influence on the Hg2+ catalyzed cyanide substitution with N-R-salt from [Ru(CN)6]4-, has been represented by a modified mechanistic approach. The concentration of ALA in various water specimens can be measured at the micro-level down to 2.5 µM using the established kinetic spectrophotometric approach. The suggested method is highly reproducible and has been effectively applied to accurately quantify the ALA in pharmaceutical samples. Even as much as 1000 with [ALA], Excipients used in medications do not significantly hinder the determination of ALA.

Clopidogrel with trade name plavix, is used effectively to reduce the incidence of ischaemic strokes, heart attacks and claudication. In this study, an ion mobility spectrometry (IMS) method was proposed for the clopidogrel determination in analytical and bio-analytical fields. Under experimental conditions, the analytical validation parameters of the proposed method were calculated and reported. The calibration graph was linear in range 30.0–2000.0 µg mL-1 for clopidogrel with two orders of magnitude and a goodness of fit, R > 0.99. The coefficient of variation (precision, n=10) was found to be within 7.5–8.6%, and also the concentration levels of 3.0 and 10.0 µg mL-1 from analyte were obtained for the limits of detection and quantification, respectively. The developed IMS method was successfully applied to determine clopidogrel with accurate recovery range (90.0–103.7%) in different matrices. The validation studies showed that the applied IMS was a simple, rapid, sensitive and reliable method for the clopidogrel analysis in the pharmaceutical and biological samples.