Electrochemical evaluation and simultaneous determination of binary mixture of antihypertensives hydrochlorothiazide and enalapril in combined dosage forms using carbon nanotubes paste electrode

Abstract

The simultaneous voltammetric determination of binary mixture containing hydrochlorothiazide (HCTZ) and enalapril (ENP) using a multi-walled carbon nanotubes paste (MWCNTsP) electrode is reported for the first time in the literature. Compared with the glassy carbon electrode or carbon paste electrode, MWCNTsP electrode showed excellent responses for the oxidation of HCTZ and especially for ENP. Square-wave voltammetry was used to simultaneous determination of HCTZ and ENP in their binary mixture in BR buffer solution (pH 5.0), which linear calibration curves were obtained in the range of 4.9×10 −7 -4.5×10 −5 mol L −1 and 5.0×10 −6 -8.3× 10 −5 mol L −1 , respectively. The detection limits were found to be 1.4×10 −8 mol L −1 and 4.1×10 −8 mol L −1 for the determination of HCTZ and ENP, respectively. The feasibility of the developed method for real sample analysis was investigated and the accuracy checked from analysis by HPLC.

Simultaneous Voltammetric Determination of Antihypertensive Drugs Amlodipine and Atenolol in Pharmaceuticals Using a Cathodically Pretreated Boron-Doped Diamond Electrode

“…The functionalized MWCNTsPE was prepared by mixing functionalized MWCNTs and mineral oil (Nujol ® ) at a ratio of 30:70% (m/m), as described previously. 29 This functionalization was attended by the treatment with mixture of HNO 3 :H 2 SO 4 (3:1, v/v) for 12 h at room temperature. Carbon paste and mineral oil were carefully homogenized in a Petri dish with a stainless steel spatula for 10 min.…”

Samarium Cuprate with Micron-Size Pores for Drug Sensing

“…Enalapril maleate, [(S)-1-[N- [1-(ethoxycarbonyl)-3-phenylpropyl]-L-alanyl]-L-proline] is an effective and safe antihypertensive prodrug [3] that is rapidly absorbed after oral administration. Following the action of hepatic esterases in the liver hydrolyze, the Enalapril maleate to the active compound enalaprilat, which is a highly specific angiotensinconverting enzyme inhibitor [4][5][6][7]. Excretion from the body goes through kidneys, with 40% of the dose excreted in the urine as enalaprilat, the rest of the dose excretes as enalapril [1].…”

“…Analytical methods for the determination of enalapril maleate in pharmaceuticals and biological fluids include high-performance liquid chromatography [8,9], colorimetry [4], and spectrophotometry [6]. These methods are highly accurate, but require costly equipment, long sample preparation and increased duration of analysis.…”

“…Electrochemical sensing has showed several appealing advantages, such as high sensitivity, simple sample preparation, low equipment cost and short analysis time [9,10]. It allows for an analysis of colored solutions, as well as solutions containing suspended substances [6]. Altogether, it significantly increased the use of electrochemical assays for the quantification of organic substances in drugs and biological samples [6].…”

Perfluorosulfonic Acid Membranes Modified with Polyaniline and Hydrothermally Treated for Potentiometric Sensor Arrays for the Analysis of Combination Drugs

“…A good resolution of oxidation peaks was achieved for some drug substances when voltammetric sensors based on a glassy carbon electrode, carbon paste electrode, or diamond electrode were used. For example, enalapril and hydrochlorothiazide can be determined using a carbon paste electrode based on functionalized carbon nanotubes [ 17 ]. The determination of captopril and hydrochlorothiazide was reported using sensors based on a carbon electrode modified with graphene and ferrocene [ 18 ] or with ionic liquid and Cu(OH) 2 nanoparticles [ 19 ].…”