Probing the interaction of anti-HIV drug Darunavir with dsDNA and HSA using electrochemical and spectroscopic measurements

Investigation of electrochemical and spectroscopic characteristics of anti-human immunodeficiency virus (HIV) drug provides important information related to the efficacy of the drug in relation with its interaction with several important biomolecules. In the present investigation we have developed an electrochemical and spectroscopic method for the detection of anti-HIV drug Darunavir (DRV) using the carbon paste as the working electrode. The analytical method has generated the detection limit of 1.86 µM (S/N = 3). The electrochemical investigations have also been carried out for the exploration of the interaction of DRV with double stranded deoxyribose nucleic acid DNA (dsDNA) and human serum albumin (HSA). Electrochemical investigations were supported from the spectroscopic measurements in evaluating the interaction. The results obtained from voltammetric and spectroscopic experiments shows strong interaction between the drug and the macromolecules. It has been observed that DRV forms strong complexes with HSA and dsDNA with the formation constants of 2.7 × 10⁴ and 4.2 × 10⁴ M^-1 respectively. The formation constants are varied with the pH of the solution, which leads to the assertion of the mechanism of the interaction between DRV and dsDNA.

Electroanalytical Methods for Determination of Calcium Channel Blockers

Background:

Calcium Channel Blockers (CCBs) are widely used in the treatment of cardiovascular and ischemic heart diseases in recent years. They treat arrhythmias by reducing cardiac cycle contraction and also benefit ischemic heart diseases. Electroanalytical 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). The purpose of this review is to gather electroanalytical methods used for the determination of calcium channel blocker drugs in pharmaceutical dosage forms and biological media selected mainly from current articles.

Methods:

This review mainly includes recent determination studies of calcium channel blockers by electroanalytical methods from pharmaceutical dosage forms and biological samples. The studies of calcium channel blockers electroanalytical determination in the literature were reviewed and interpreted.

Results:

There are a lot of studies on amlodipine and nifedipine, but the number of studies on benidipine, cilnidipine, felodipine, isradipine, lercanidipine, lacidipine, levamlodipine, manidipine, nicardipine, nilvadipine, nimodipine, nisoldipine, nitrendipine, diltiazem, and verapamil are limited in the literature. In these studies, DPV and SWV are the most used methods. The other methods were used less for the determination of calcium channel blocker drugs.

Conclusion:

Electroanalytical methods especially voltammetric methods supply reproducible and reliable results for the analysis of the analyte. These methods are simple, more sensitive, rapid and inexpensive compared to the usually used spectroscopic and chromatographic methods.

One-by-one imprinting in two eccentric layers of hollow core-shells: Sequential electroanalysis of anti-HIV drugs

Double layered one-by-one imprinted hollow core-shells@ pencil graphite electrode was fabricated for sequential sensing of anti-HIV drugs. For this, two eccentric layers were developed on the surface of vinylated silica nanospheres to obtain double layered one-by-one imprinted solid core-shells. This yielded hollow core-shells on treatment with hydrofluoric acid. The modified hollow core-shells (single layered dual imprinted) evolved competitive diffusion of probe/analyte molecules. However, the corresponding double layered one-by-one imprinted hollow core-shells (outer layer imprinted with Zidovudine, and inner layer with Lamivudine) were found relatively better owing to their bilateral diffusions into molecular cavities, without any competition. The entire work is based on differential pulse anodic stripping voltammetry at double layered one-by-one imprinted hollow core-shells. This resulted in indirect detection of electro inactive targets with limits of detection as low as 0.91 and 0.12 (aqueous sample), 0.94 and 0.13 (blood serum), and 0.99 and 0.20 ng mL^-1 (pharmaceutics) for lamivudine and zidovudine, respectively in anti-HIV drug combination.