Green and cost-effective voltammetric assay for spiramycin based on activated glassy carbon electrode and its applications to urine and milk samples.

A simple, cost-effective, and efficient differential pulse voltammetric (DPV) assay for monitoring spiramycin adipate (SPA) in its dosage forms, urine, and milk samples at an activated glassy carbon electrode (GCE) was developed. GCE was electrochemically activated by anodization at a high positive voltage (2.5 V). The activated glassy carbon electrode (AGCE) was surface characterized, optimized, and utilized for the electrochemical assay of SPA. The electrochemical behavior of the AGCEs was investigated using cyclic voltammetry (CV) which shows a remarkable increase in the anodic peak of SPA in comparison with GCE. This behavior reflects a remarkable increase in the electrocatalytic oxidation of SPA at AGCE. The impacts of various parameters such as scan rate, accumulation time, and pH were investigated. The analytical performance of the activated glassy carbon electrodes was studied utilizing DPV. Under optimum conditions, the oxidation peak current exhibited two linear ranges of 80 nm to 0.8 µM and 0.85-300 µM with a lower limit of detection (LOD) of 20 nM. The developed assay exhibited high sensitivity, excellent repeatability, and good selectivity. Additionally, the developed SPA-sensitive modified GCE was successfully applied for SPA assay in its pharmaceutical dosage form and diluted biological fluids as well, with satisfactory recovery results which correlated well with the results obtained using spectrophotometry.

Simple spectrofluorimetric methods for determination of veterinary antibiotic drug (apramycin sulfate) in pharmaceutical preparations and milk samples.

This work describes the development of highly sensitive as well as simple two spectrofluorimetric methods for the determination of apramycin sulfate. The first method depends on measuring the inherent native fluorescence of the aqueous neutral solution of the drug at 388 nm (λex 335 nm). While the second method mainly based on enhancing the native fluorescence intensity of the drug using sodium dodecyl sulfate (SDS) micellar media by about 4 fold enhancement. The fluorescence intensity - concentration relationship for the two methods was found rectilinear over the concentration range 1.0-100.0 and 0.1-20.0 µg/mL for the first and second method respectively. The limit of detection for method I and II were 0.05 and 0.02 µg/mL respectively. The proposed methods can be effectively connected for the assurance of the medication without impedances from common normal excipients. Furthermore, the two methods were high sensitive enough for the assurance of the drug in spiked milk samples with high percentage recoveries.