Determination Of Rizatriptan Benzoate Research Articles

A Gr/αFe2O3/Carbon Paste Electrode Developed as an Electrochemical Sensor for Determination of Rizatriptan Benzoate: An Antimigraine Drug

AbstractIn this research, a new electrochemical sensor was proposed for determining rizatriptan benzoate (RZB) with high sensitivity. To this end, a nanocomposite consisting of graphene (Gr) and hematite iron oxide (αFe2O3) was used to modify a carbon paste electrode (CPE). Field emission scanning electron microscopy (FESEM) was employed to study the morphology of the fabricated electrode; cyclic voltammetry (CV), chronoamperometry (CA), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV) were utilized to evaluate the modified electrode's capabilities. The findings demonstrated the high sensitivity of the designed electrode in the determination of RZB. In addition, to optimize the response of the electrochemical sensor, changes in the voltammetric behavior of RZB under different scan rates and pH conditions were explored. The results showed that under optimal conditions, RZB concentrations between 2 and 50 μM induced an oxidation anodic peak current that could detect the substance with a low limit of merely 0.42 μM. The findings of the present study demonstrated the fabricated electrode high sensitivity, low detection limit, wide linear dynamic range, remarkable reproducibility, rapid response, and high current peak response in detecting various concentrations of RZB. Furthermore, a kinetically facile system with minimal charge transfer resistance and adequate RZB diffusion was present on the electrode surface. Finally, the proposed electrode was successfully utilized in the detection of RZB in various samples.

Validated Spectrophotometric Determination of Rizatriptan Benzoate in Pharmaceutical Formulations using Alizarin Derivatives

Two simple, sensitive, accurate, precise and economical spectrophotometric methods have been developed and validated for the determination of rizatriptan benzoate (RZT) in pure form and pharmaceutical formulations. These methods were based on the formation of charge transfer complex between RZT as n-electron donor and alizarin red S (ARS) or quinalizarin (Quinz) as π-acceptor in methanol to form highly colored chromogens which showed an absorption maximum at 532 and 574 nm using ARS and Quinz, respectively. The optimization of the reaction conditions such as the type of solvent, reagent concentration and reaction time were investigated. Under the optimum conditions, Beer’s law is obeyed in the concentration ranges 1.0-16 and 2.0-20 g mL-1 using ARS and Quinz, respectively with good correlation coefficient (r2 ≥ 0.9996) and with a relative standard deviation (RSD% ≤ 1.16). The molar absorptivity, Sandell sensitivity, detection and quantification limits were also calculated. The methods were successfully applied to the determination of RZT in its pharmaceutical formulations and the validity assesses by applying the standard addition technique. Results obtained by the proposed methods for the pure RZT and commercial tablets agreed well with those obtained by the reported method.

Utility of p-Chloranilic Acid and 2,3-Dichloro-5,6-dicyano-p-benzoquinone for the Spectrophotometric Determination of Rizatriptan Benzoate

Rizatriptan is a new selective 5-HT1B/1D agonist which is used in the treatment of migraine headaches. Two simple, rapid, accurate, and economical spectrophotometric methods are described for the determination of rizatriptan benzoate (RTB) in its pure form and pharmaceutical preparations. These methods are based on the charge-transfer complexation reaction between rizatriptan benzoate as n-electron donor and p-chloranilic acid (p-CA) or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as π-acceptor to form highly colored chromogens. The chromogens formed by the reaction between RTB and p-CA peaked at 530 nm (method A) and that formed by the reaction between RTB and DDQ peaked at 590 nm (method B). Under the optimum conditions Beer’s law is obeyed in the concentration range of 14–245 μg mL−1 for method A and 4–70 μg mL−1 for method B. The coefficient of correlation was found to be 0.9999 for both methods. The molar absorptivity, Sandell sensitivity, limits of detection, and quantification are also reported. The stoichiometric relationship determined by Job’s continuous method was found to be 1 : 1 (drug : reagent) for both methods. Both methods were applied to determination of RTB in the pharmaceutical formulations. Results of the analysis were validated statistically.

Application of Multicriteria Methodology in the Development of Improved RP-LC-DAD for Determination of Rizatriptan and Its Degradation Products

The aim of this study was to establish an improved isocratic RP-LC-DAD method for separation and determination of rizatriptan benzoate and its two degradation products, L-749.019 and L-783.540 in tablets. Since the chromatographic behavior of target substances can be influenced by various experimental parameters, the whole study was carried out by employing experimental design methodology. The investigation included the influence of mutual changes of the mobile phase composition (methanol amount in the range 3–7% and pH of the water phase from 5.0 to 6.0) and the temperature (from 20 to 30 °C). The response surface design by means of Box-Brehnken design was used to obtain a predictive model which describes the changes in the response within the experimental domain. Additionally, several different target responses were evaluated and Derringer’s desirability function was used for reaching a suitable compromise among the responses. This multi-criteria decision making approach is based on constructing a desirability function for each individual response and afterwards establishing the overall desirability function. Such methodology provided us with the best operating conditions, satisfactory resolutions between the analytes and the shortest possible total analysis time. The experiments were performed on C18 XTerra (150 mm × 3.9 mm), 5 μm column with the mobile phase consisting of a mixture of methanol, TEA and 0.01 mol L−1 KH2PO4 (6:9.4:84.6 v/v) pumped at a flow rate of 1.2 mL min−1, pH of the water phase adjusted to 6 with 85% orthophosphoric acid, a column temperature of 20 °C and detection at 225 nm. Afterwards, the new method was validated and subsequently applied in analysis of commercially available rizatriptan tablets.