Voltammetric determination of fenbendazole in veterinarian formulations

HPLC Determination of Imidazoles with Variant Anti-Infective Activity in Their Dosage Forms and Human Plasma

A suitable HPLC method has been selected and validated for rapid simultaneous separation and determination of four imidazole anti-infective drugs, secnidazole, omeprazole, albendazole, and fenbendazole, in their final dosage forms, in addition to human plasma within 5 min. The method suitability was derived from the superiority of using the environmentally benign solvent, methanol over acetonitrile as a mobile phase component in respect of safety issues and migration times. Separation of the four anti-infective drugs was performed on a Thermo Scientific^® BDS Hypersil C₈ column (5 µm, 2.50 × 4.60 mm) using a mobile phase consist of MeOH: 0.025 M KH₂PO₄ (70:30, v/v) adjusted to pH 3.20 with ortho-phosphoric acid at room temperature. The flow rate was 1.00 mL/min and maximum absorption was measured with UV detector set at 300 nm. Limits of detection were reported to be 0.41, 0.13, 0.18, and 0.15 µg/mL for secnidazole, omeprazole, albendazole, and fenbendazole, respectively, showing a high degree of the method sensitivity. The method of analysis was validated according to Food and Drug Administration (FDA)guidelines for the determination of the drugs, either in their dosage forms with highly precise recoveries, or clinically in human plasma, especially regarding pharmacokinetic and bioequivalence studies.

Voltammetric Techniques for the Analysis of Drugs using Nanomaterials based Chemically Modified Electrodes

Background:

Electroanalytical techniques play a very important role in the areas of medicinal, clinical as well as pharmaceutical research. Amongst these techniques, the voltammetric methods for the determination of drugs using nanomaterials based chemically modified electrodes (CMEs) have received enormous attention in recent years. This is due to the sensitivity and selectivity they provide on qualitative as well as quantitative aspects of the electroactive analyte under study. The aim of the present review was to discuss the work on nanomaterials based CMEs for the analysis of drugs covering the period from 2000 to present employing various voltammetric techniques for different classes of the drugs.

Methods:

The present review deals with the determination of different classes of drugs including analgesics, anthelmentic, anti-TB, cardiovascular, antipsychotics and anti-allergic, antibiotic and gastrointestinal drugs. Also, a special section is devoted for enantioanalysis of certain chiral drugs using voltammetry. The detailed information of the voltammetric determination for the drugs from each class employing various techniques such as differential pulse voltammetry, cyclic voltammetry, linear sweep voltammetry, square wave voltammetry, stripping voltammetry, etc. are presented in tabular form below the description of each class in the review.

Results:

Various nanomaterials including carbon nanotubes, graphene, carbon nanofibers, quantum dots, metal/metal oxide nanoparticles, polymer based nanocomposites have been used by researchers for the development of CMEs over a period of time. The large surface area to volume ratio, high conductivity, electrocatalytic activity and biocompatibility make them ideal modifiers where they produce synergistic effect which helps in trace level determination of pharmaceutical, biomedical and medicinal compounds. In addition, macrocyclic compounds as chiral selectors have been used for the determination of enantiomeric drugs where one of the isomers captured in the cavities of chiral selector shows stronger binding interaction for one of the enantiomorphs.

Conclusion:

arious kinds of functional nanocomposites have led to the manipulation of peak potential due to drug - nanoparticles interaction at the modified electrode surface. This has facilitated the simultaneous determination of drugs with almost similar peak potentials. Also, it leads to the enhancement in voltammetric response of the analytes. It is expected that such modified electrodes can be easily miniaturized and used as portable, wearable and user friendly devices. This will pave a way for in-vivo onsite real monitoring of single as well as multi component pharmaceutical compounds.

Comparative study on the selectivity of various spectrophotometric techniques for the determination of binary mixture of fenbendazole and rafoxanide

Five different spectrophotometric methods were applied for simultaneous determination of fenbendazole and rafoxanide in their binary mixture; namely first derivative, derivative ratio, ratio difference, dual wavelength and H-point standard addition spectrophotometric methods. Different factors affecting each of the applied spectrophotometric methods were studied and the selectivity of the applied methods was compared. The applied methods were validated as per the ICH guidelines and good accuracy; specificity and precision were proven within the concentration range of 5-50 μg/mL for both drugs. Statistical analysis using one-way ANOVA proved no significant differences among the proposed methods for the determination of the two drugs. The proposed methods successfully determined both drugs in laboratory prepared and commercially available binary mixtures, and were found applicable for the routine analysis in quality control laboratories.