Economical Voltammetric Sensor for Sensitive Rapid Determination of Ondansetron in the Presence of Opioid Antagonist Naltrexone

Eco-friendly electrochemical sensor for determination of conscious sedating drug "midazolam'' based on Au-NPs@Silica modified carbon paste electrode

Benzodiazepines (BZDs) are a group of drugs prescribed for their sedating effect. Their misuse and addictive properties stipulate different authorities for developing simple, fast and accurate analytical methods for instantaneous detection. Differential pulse voltammetric technique (DPV) was utilized for the selective assay of midazolam hydrochloride (MDZ) in the pure, parenteral dosage forms and plasma samples. A chemically modified carbon paste electrode (CPE) was implemented during the study. The method depended on the electroreduction of MDZ on the surface of the electrode over a potential range of 0.0 V to -1.6 V. The electrode was fabricated using silica nanoparticles (Si-NPs) which were incorporated into the composition of the CPE and used to enhance the electrode performance. Then, to enhance the sensitivity of the method, a chronoamperometric modification step was applied for depositing gold nanoparticles (Au-NPs) on the carbon paste electrode surface. Modification with Au-NPs showed a higher reduction current peak for MDZ with well-defined peaks. Various parameters such as pH of the media and measurements scan rate were investigated and optimized to enhance the sensor sensitivity. The sensor showed a dynamic linear response over a concentration range of 4.0 × 10-7 M to 2.9 × 10-4 M of MDZ with a LOD of 2.24 × 10-8 M using 0.1 M acetate buffer (pH 5.6). The sensor was validated in accordance with the ICH guidelines regarding accuracy, precision and specificity for the selective assay of MDZ in the presence of excipients. A greenness evaluation was performed using three different assessment tools, namely, the "Green Analytical Procedure Index" (GAPI), the "Analytical Greenness metric" (AGREE) and the "Whiteness Analytical Chemistry tool" (WAC) using the RGB12 model.

Analytical Eco-Scale for Evaluating the Uniqueness of Voltammetric Method used for Determination of Antiemetic Binary Mixture Containing Doxylamine Succinate in Presence of its Toxic Metabolite

Green analytical procedures are gaining popularity in the pharmaceutical research area as a way to reduce environmental impact and improve analyst health safety. The current work presents a green and sensitive electrochemical carbon paste electrode that has been chemically modified with zirconium dioxide and multi-walled carbon nanotubes for estimation of pyridoxine HCl (PYR) and doxylamine succinate (DOX) using the square wave voltammetric technique. Under optimum conditions, the linearity ranges were 20.00–2000.00 ng mL−1 and 2.00–20.00 µg mL−1 for both drugs in the 1st linear segment and 2nd linear segment, respectively. Stability testing assesses how the quality of a drug substance changes over time, depending on environmental and laboratory factors. DOX was found to undergo oxidative degradation when refluxed for 7 h using 30% H2O2 and the degraded product (DOX DEG) (toxic metabolite) was successfully characterized utilizing LC–MS. The developed electrode showed selectivity for the determination of binary mixture in pure form, pharmaceutical form, and in the presence of DOX DEG and common interfering molecules with good recovery. The proposed method was found to be eco-friendlier than the reported method in terms of the use of hazardous chemicals and solvents, energy consumption, and waste generation.

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