Development and Validation of a Quantitative NMR Method for the Determination of the Commercial Tablet Formulation of Sulfasalazine

Development of a Quantitative NMR Method for Direct and Simultaneous Determination of Four Flavonoids in Scutellaria baicalensis georgi Extracts

Introduction:

Scutellaria Baicalensis Georgi (SBG), a Traditional Chinese Medicine (TCM) used for the treatment of antiviral therapy, contains many flavonoids.

Materials and Methods:

A simple, fast and accurate 1H quantitative nuclear magnetic resonance (1HqNMR) method was established for simultaneously determination of four flavonoids (Baicalin, Baicalein, Wogonin and Wogonoside) in SBG extract by using 3,4,5-trichloropyridine as an internal standard (IS). All the NMR determination work was performed at 308 K on an NMR sample tube inserted with a co-axial tube. The NMR sample tube was added with the sample (SBG extract and IS), the co-axial insert tube was added with D2O. Quantification of four flavonoids was carried out by calculating the relative peak area ratio of the selected proton signals from the target compounds and the IS.

Results:

The validated 1H-qNMR method was successfully used to determine the four flavonoids in 9 batches of SBG from different origins and the results were in good accordance with those obtained from HPLC.

Conclusion:

The established 1H-qNMR method could be used as a powerful tool for the quality control of SBG from different sources and had potential in the quantification of main components from other TCMs.

Determination of Budesonide and Sulfasalazine in Water and Wastewater Samples Using DLLME-SFO-HPLC-UV Method

Dispersive liquid–liquid microextraction based on solidification of floating organic droplet (DLLME-SFO) was applied to isolate budesonide (BUD) and sulfasalazine (SULF) from aqueous samples. The effects of different parameters on the efficiency on the extraction such as type of extrahent and dispersive solvent, ionic strength, pH of sample, and centrifugation time were investigated. Moreover, the influence of foreign substances on a studied process was tested. The calibration curves were recorded. The linearity ranges for BUD and SULF were 0.022–8.611 µg mL−1 and 0.020–7.968 µg mL−1 with the limit of detection (LOD) 0.011 µg mL−1 and 0.012 µg mL−1, respectively. The enrichment factors (EF) for two analytes were high: for BUD it was 145.7 and for SULF, 119.5. The elaborated procedure was applied for HPLC-UV determination of these analytes in water and wastewater samples.