Cathodic adsorptive stripping voltammetric studies on lamivudine: An antiretroviral drug

Voltammetric Methods Used in the Determination of Nucleoside Reverse Transcriptase Inhibitors

Background:

The Human Immunodeficiency Virus (HIV) has now been established as the causative agent of the Acquired Immunodeficiency Syndrome (AIDS) and exactly 25 antiretroviral drugs have been formally approved for clinical use in the treatment of AIDS. The life quality and duration of HIV-positive patients have increased with the usage of antiretroviral drugs in the treatment of AIDS. Nucleoside Reverse Transcriptase Inhibitors (NRTIs) are one of the subgroups of antiretroviral.

Objective:

The quantification of drugs is important, as they make positive contributions to dose adjustments in practice. Voltammetric methods are very powerful analytical methods used in the pharmaceutical industry because of the determination of therapeutic agents and/or their metabolites in clinical samples at extremely low concentrations (10-50 ng/ml).

Methods:

This review mainly includes the pharmacological properties and recent determination studies by voltammetric methods from pharmaceutical dosage forms and biological samples of eight NRTIs group antiretroviral drugs (zidovudine, abacavir, adefovir, entecavir, zalcitabine, didanosine, emtricitabine, lamivudine) that are used in the clinic and show electroactive properties, were performed.

Conclusion:

Due to the variety of working electrodes in voltammetric methods, it is possible to choose the electrode that best responds. In this way, the analysis of NRTIs was possible at lower concentrations in pharmaceuticals and biological samples with voltammetric methods in these studies without the necessity for the sample pre-treatment or time-consuming extraction steps. The voltammetric methods provide good stability, repeatability, reproducibility and high recovery for the analysis of the analyte. They could be used for the pharmacokinetic studies as well as for quality control laboratory studies.

A Review of Electroanalytical Techniques for Determination of Anti-HIV Drugs

Until now after the human immunodeficiency virus (HIV) was discovered as the then tentative aetiological agent of acquired immune deficiency syndrome (AIDS), exactly 25 anti-HIV compounds have been formally approved for clinical use in the treatment of AIDS. These compounds fall into six categories: nucleoside reverse transcriptase inhibitors (NRTIs: zidovudine, didanosine, zalcitabine, lamivudine, abacavir, stavudine, and emtricitabine), nucleotide reverse transcriptase inhibitors (NtRTIs: tenofovir), nonnucleoside reverse transcriptase inhibitors (NNRTIs: efavirenz, nevirapine, delavirdine, and etravirine), protease inhibitors (PIs: ritonavir, indinavir, saquinavir, nelfinavir, amprenavir, lopinavir, fosamprenavir, atazanavir, tipranavir and darunavir), fusion inhibitors (FIs: enfuvirtide), coreceptor inhibitors (CRIs: maraviroc), and integrase inhibitors (INIs: raltegravir). The present paper submitted the use of various electroanalytical techniques for the determination of anti-HIV drugs. This paper covers the time period from 1990 to 2010 including voltammetric techniques that were reported. Presented application concerns analysis of anti-HIV drugs from pharmaceutical dosage forms and biological samples.

Adsorptive stripping voltammetric behavior of nortriptyline hydrochloride and its determination in surfactant media

The effect of adding surface active agents to electrolytes containing nortriptyline hydrochloride on the voltammetric response of a hanging mercury drop electrode (HMDE) was studied. The current signal due to the reduction process was a function of the amount of nortriptyline hydrochloride, pH of the medium, type of the surfactant, and accumulation time at the electrode surface. Addition of Tween-20 to the nortriptyline hydrochloride containing electrolyte enhances the reduction current signal. Voltammograms of the drug with Tween-20 in Britton Robinson buffers of pH 2-11 exhibit a single well-defined reduction peak, which may be due to the reduction of -C horizontal lineC group. The reduction process was irreversible over the entire pH range, and the mechanism of reduction was postulated on the basis of controlled potential electrolysis and coulometry. Application of Tween-20 in the electrochemical determination of nortriptyline hydrochloride using square-wave voltammetry at the HMDE enhanced the detection limit of the analyte concentration from 8.24 ng/mL in the absence of surfactant to 0.92 ng/mL when present.