EDTA salt modified carbon paste electrode for square wave voltammetric determination of theophylline in pharmaceutical tablet formulation

Abstract

In this study, a square wave voltammetric method for determination of theophylline in tablet formulation based on EDTA salt modified carbon paste electrode is presented. CV, FT-IR, and EIS results confirmed modification of the carbon paste with EDTA salt. In contrast to the unmodified carbon paste electrode, the modified carbon paste electrode showed irreversible oxidation of theophylline with considerable current enhancement. Investigation of the effect of scan rate on the Ip and Ep response of the modified electrode for theophylline revealed predominantly diffusion controlled oxidation kinetics. Under the optimized conditions, square wave oxidative peak current of theophylline in pH 7.0 PBS showed linear dependence on concentration in the range 10–200 μM with determination coefficient (R2), limit of detection, and limit of quantification of 0.99782, 0.0257 μM, and 0.0857 μM, respectively. Detection of an amount of theophylline in the analyzed tablet formulation with 1.85% error from its nominal content (120 mg/tablet) confirmed the accuracy of the developed method. Spike and interference recovery results of 98.59%, and 95.7–100%, respectively validated the applicability of the developed method for determination of theophylline content in tablet samples.

Electrochemical sensor based on a poly-murexide modified carbon paste electrode for determination of fluoroquinolone antibiotic ciprofloxacin

“…The linear relationship and the high value of correlation coefficient (0.99) of the regression equation obtained from the plot of the anodic peak current (Ip) against the square root of the scan rate (𝜈 1/2 ) denotes that the CFLOX oxidation process was diffusion-controlled on the PMUX/CPE surface (Fig. 9B) (Khodari et al, 2018 ;Moges et al, 2022):…”

A novel fluorescent aptasensor for the detection of theophylline based on cryonase‐driven signal amplification strategy

“…It is mainly used to treat bronchitis, chronic obstructive pulmonary disease, cardiogenic asthma, and so on [2]. However, the effective blood concentration range of theophylline acceptable to normal people is only 5–20 μg/mL [3], and an elevated blood concentration easily leads to poisoning, so it is necessary to detect the blood concentration of theophylline in real time for these patients using theophylline drugs.…”

“…It is mainly used to treat bronchitis, chronic obstructive pulmonary disease, cardiogenic asthma, and so on [2]. However, the effective blood concentration range of theophylline acceptable to normal people is only 5-20 μg/mL [3], and an elevated blood concentration easily leads to poisoning, so it is necessary to detect the blood concentration of theophylline in real time for these patients using theophylline drugs. So far, numerous clinical tests for theophylline in serum or plasma have been developed, such as hydrophilic interaction chromatography-tandem mass spectrometry (HILIC-MS/MS) [4], colorimetric [5], capillary electrophoresis [6], and so on.…”