Electrochemistry of the COMT Enzyme Inhibitor Entacapone and Its Determination in Pharmaceutical Formulation and Human Blood-Pharmacokinetic Study

Abstract

Entacapone (ENT) is a potent inhibitor of catechol-O-methyltransferase enzyme. ENT is reduced via two irreversible cathodic waves over the pH range 2.0–11.5. It has strong interfacial adsorptive behavior onto Hg electrode surface. Langmuir isotherm indicated monolayer adsorption and the equilibrium parameter RL value (0.40 – 0.93) indicated that sorption process was favorable. A monolayer surface coverage of 6.06 × 10−10 mol cm−2 was estimated and each adsorbed ENT molecule occupied an area of 0.27 nm2. Taking advantage of the adsorption features of ENT, a sensitive and selective square-wave adsorptive cathodic stripping voltammetric (SW-AdCSV) method was developed for trace determination of ENT in pure form, commercial formulations (in Comtan tablets; as a single active drug and in Stalevo 200 tablets; as tertiary mixture of ENT, levodopa and carbidopa) and in human serum. Limits of quantification (LOQ) of 5.0 × 10−10 and 1.3 × 10−9 mol L−1 ENT were achieved in pure form and in spiked human serum, respectively. This analysis was carried out without addition of any surfactant, extraction of the drug and interference from some common excipients, co-formulated and co-administrated drugs. The proposed method has also been successfully applied for assay of ENT in real plasma samples and seems to be suitable for therapeutic drug monitoring purposes.

A Recyclable Luminescent MOF Sensor for On‐Site Detection of Insecticide Dinotefuran and Anti‐Parkinson's Drug Entacapone in Various Environmental and Biological Specimens

“…[24] Therefore, it is very important to regulate and address the environmental impacts of pharmaceuticals while emphasizing proper disposal and wastewater management. [25] There is continuous advancement of sensing technologies such as micellar electro kinetic chromatography, [5] electrochemical [26] and enzyme-linked immunosorbent assay [27] for the detection of dinotefuran and differential pulse polarography, [28] differential pulse voltammetry, [23] square ware voltammetry [20] and amperometry [21] for the detection of entacapone. Among all the above-mentioned detection methods, fluorometry is highly favourable over the other techniques due to its cost effectiveness, high sensitivity, simple instrumentation and user-friendly nature.…”

“…Conventional wastewater treatment plants may not completely remove pharmaceuticals, posing challenges to water quality [24] . Therefore, it is very important to regulate and address the environmental impacts of pharmaceuticals while emphasizing proper disposal and wastewater management [25] …”

Molecularly Imprinted Poly‐o‐phenylenediamine Electrochemical Sensor for Entacapone

“…Most of these methods offer good selectivity and a low detection limit, but cannot be widely applied because of the high cost, time-consuming, and some are tedious and needs pre-separation steps. Electrochemical methods offer another opportunity to determine ETC, as it is an electroactive compound, therefore electroanalytical methods based on the reduction of ETC on hanging drop mercury electrode [13][14], the oxidation of ETC on carbon paste electrode [15] or using multi-walled carbon nanotubes decorated on GCE [16] are developed. Highly selective and sensitive electrodes able to detect ETC in biological fluids, have yet to be developed.…”

3D Bismuth Ferrite Microflowers Electrochemical Sensor for the Multiple Detection of Pesticides

“…Therefore, electrochemical methods have received an increased attention due to their simplicity, sensitivity and more feasible analysis. [19][20][21][22][23][24][25][26][27][28][29][30][31][32] Since IMD exhibits an electrochemical activity, there is a significant growth in electroanalytical methods to determine this compound in different matrices. However, for FIP there are few reports in literature for its electrochemical detection.…”