Comparison Study of Voltammetric Behavior of Muscle Relaxant Dantrolene Sodium on Silver Solid Amalgam and Bismuth Film Electrodes

Turn-off fluorescence of S,N-doped carbon dots for determination of two nitro-containing drugs in dosage forms and human plasma

This study describes the development of an environmentally-friend optical nanosensor for the rapid spectrofluorimetric assessment of two nitro-compounds, namely nitrofurantoin and dantrolene in their dosage forms and plasma samples. A one-step synthetic technique successfully created very bright water-soluble carbon quantum dots doped with sulfur and nitrogen (S,N-CQDs). Carbon was derived from citric acid, while nitrogen and sulfur were obtained from thiosemicarbazide. The dimensions of the synthesized dots were measured using a high-resolution transmission electron microscope. FT-IR spectroscopy was used to determine which functional groups were located on their surfaces. The nanosensor's fluorescence emission peaked intensely at 415 nm after excitation at 345 nm with a quantum yield of about 0.52. The inherent fluorescence of the nanosensors gradually decreased upon addition of the studied analytes in increasing concentrations. The fluorescence reduction of nanosensor with the concentrations of the investigated drugs demonstrated linear correlation within the ranges of 0.5-8.0 μg/mL and 1.0-10.0 μg/mL with limits of detection of 0.14 μg/mL (0.59 μM) and 0.23 μg/mL (0.73 μM) for nitrofurantoin and dantrolene, respectively. The recommended method was used to determine the concentrations of the investigated drugs in their commercial capsules, with recoveries ranging from 97.90 % to 101.57 % and low percent RSD values less than 2 %. Moreover, the method was adapted for the in-vitro analysis of the two analytes in spiked human plasma samples with % recoveries from 95.20 % to 102.20 %. The mechanism of interaction between each analyte and the dots was also investigated. The selectivity of the approach for measuring analytes concentration in the presence of excipients, co-formulated medications, or co-administered pharmaceuticals was further evaluated through an interference study. The suggested method's validity was evaluated in accordance with ICH criteria.

Green spectrofluorimetric assay of dantrolene sodium via reduction method: application to content uniformity testing

Green analysis has turned out to be of a great value in all areas, including pharmaceutical analysis. Thus, it is extremely important to consider the environmental influence of each step in developing any analysis technique. The present work illustrates a validated, simple and green spectrofluorimetric method for the analysis of dantrolene sodium (DAN). The developed process is characterized by being of high sensitivity as well as being relatively inexpensive. The suggested technique based on the formation of a highly fluorescent product of DAN via its reduction by the aid of Zn/HCl system. The resulting fluorophore showed a powerful fluorescence at λ _em 344 nm after excitation at λ _ex 279 nm. Calibration graph revealed a great linear regression (r = 0.9998) within concentration ranging from 0.05 to 2.0 µg ml^-1. The suggested method had very low detection and quantification limits of 0.010 and 0.031 µg ml^-1, respectively. The applied technique was effectively used in the determination of DAN in its pharmaceutical preparations. The results were compared with those from using the official United States Pharmacopeia (USP) method and they were in a good agreement. Moreover, content uniformity testing of DAN in capsules was performed adopting the investigated technique with satisfying results. The greenness of the suggested technique was confirmed by the three standard assessment tools. Therefore, the developed technique can be used in the routine quality control analysis of DAN with minimum harmful impact on nature or individuals.

Voltammetric analysis of dantrolene and its active metabolite with indomethacin in rat plasma

AIM

Differential pulse polarography was used for the concurrent analysis of the coadministered dantrolene (DAN) and indomethacin (IND) in plasma.

MATERIALS & METHODS

DAN and IND, Hanging mercury drop electrode and Britton-Robinson buffer at pH 5 were used. In plasma, cathodic reduction of DAN nitro group and its active metabolite at -0.2 V was done. IND was analyzed after carbonyl group reduction at -1.1 V.

RESULTS

Drugs determination in rat plasma with good recoveries and low limit of quantitation was done. Application to trace analysis of drugs in rat plasma was done with C_max and T_max determination.

CONCLUSION

This technique shows high sensitivity, simplicity and low cost. The method is US FDA validated and it is applicable to human level.

Comparison Study of Voltammetric Behavior of Muscle Relaxant Dantrolene Sodium on Silver Solid Amalgam and Bismuth Film Electrodes

Voltammetric behavior of muscle relaxant dantrolene sodium (DAN) was studied and the voltammetric methods for its determination using polished and mercury meniscus modified silver solid amalgam electrodes (p-AgSAE and m-AgSAE) as well as using bismuth film electrode (BiFE, ex situ plating on GCE) have been proposed. These working electrodes represent the most commonly used alternatives to mercury ones which come wrongfully into disfavor because of alleged toxicity of mercury. Within this work, the obtained results of DAN determination have been completed by corresponding statistical parameters and also some electrochemical characteristics of AgSAEs and BiFE were assessed, especially in comparison with the mercury electrodes.