Application of a Continuous Square-Wave Potential Program for Sub Nano Molar Determination of Ketotifen

Abstract

117Ketotifen fumarate [KTF; 10H-benzo(4,5)cyclohepta(1,2-b) thiophen-10-one, 4,9-dihydro-4-(1-methyl-4-piperidinylidene)-(E)-2-butenedioate] is a nonspecific, oral mast cell stabilizer. Its main biochemical pharmacological activities are H receptor antagonism, phosphodiesterase inhibition and inhibition of calcium flux in smooth muscle preparations.1) It is applied to prevent the development of allergic conjunctivitis 2,3) asthma 4,5) and even showed an anti-wrinkle effect. 6)Asthma is a substantial health problem among children and adults worldwide, with high and increasing prevalence rates in many countries. More than 7% of Iranian children (4 million) are suffering from asthma according to the first National Asthma Prevalence Study. Oral salbutamol, aminophylline and ketotifen have been commonly used for asthma management. Ketotifen is one of the rare drugs that has been extensively used and shown safe in children. Ketotifen is an antihistamine. Histamine can produce allergy symptoms such as sneezing, runny nose, and watery eyes. Ketotifen is used to treat itching of the eyes caused by allergy to dust, pollen, animals and other allergens. For determination of ketotifen several methods such as ultraviolet-visible (UV-vis) spectrophotometry, 7,8) high performance liquid chromatography (HPLC), 9) gas chromatography-mass spectrometry (GC-MS) 10) and liquid chromatography-mass spectrometry (LC-MS) 11) has been used. The combination of microelectrode (ME) with squarewave voltammetry (SWV) has recently been shown advantageous for environmental detection of several compounds.12)The adaptation of this technology to adsorptive stripping voltammetry (ASV) of ketotifen on a gold ME could provide a substantial improvement for rapid analysis. 13,14) This paper describes a fundamentally different approach to SWV measurement, in which the detection limits are improved, while preserving the information content of the SW voltammogram. The approach is designed to separate the voltammetric signal and background signal in frequency domain by using discrete fast Fourier transformation (FFT) method. Further improvement in the signal was gained by two-dimensional integration of the electrode response over a selected potential range and time window of the signal. Although at sufficiently high scan rates cyclic voltammetry (CV) can approximate an ac voltammetric technique and can be used to investigate electrode surface phenomena such as physical adsorption, FFT-SWV may be a more appropriate technique for monitoring analyte adsorption, since the potential dependence of analyte adsorption may be more clearly characterized. SWV measures the current response while rapid alternating potentials are applied during a staircase scan whereas cyclic voltammetry which uses a forward and reverse linear dc scan is not sensitive to the potential dependence of changes that occur in the double layer. ExperimentalReagents All solutions were prepared in double-distilled water using analytical-grade reagents. Reagents in use in preparation of the stock ...

Charge Transfer Complexes of Ketotifen with 2,3-Dichloro-5,6-dicyano-p-benzoquinone and 7,7,8,8-Tetracyanoquodimethane: Spectroscopic Characterization Studies

“…The primary biochemical and pharmacological activity of KT is exerted by acting as a H1-receptor antagonist and phosphodiesterase inhibitor, leading to the inhibition of calcium flux in smooth muscle. Different analytical techniques have been reported to determine KT [ 16 , 17 , 18 , 19 , 20 , 21 ], but most are time-consuming, costly, or require derivatization. CT complexes in combination with spectrophotometry represent a cheaper and faster alternative for the quantification of KT based on a colorimetric measurement.…”

Carcinoembryonic Antigen Admittance Biosensor Based on Au and ZnO Nanoparticles Using FFT Admittance Voltammetry

“…The detection method, fast Fourier transform square wave voltammetry (FFTSWV), which is used here, is very sensitive, inexpensive, and fast. The square wave voltammetry (SWV) has recently been shown to be advantageous for environmental detection of several compounds. − This paper describes a fundamentally different approach to SWV measurement, in which the detection limits are improved, while preserving the information content of the SW voltammogram. In fact, the analyte signal is calculated based on admittance changes related to the changes in electrical double layer.…”