Characterization and electrochemical investigations of micellar/drug interactions

Drug-ionic surfactant interactions: density, sound speed, spectroscopic, and electrochemical studies

The failure of antibiotics against infectious diseases has become a global health issue due to the incessant use of antibiotics in the community and a lack of entry of new antibacterial drugs onto the market. The limited knowledge of biophysical interactions of existing antibiotics with bio-membranes is one of the major hurdles to design and develop more effective antibiotics. Surfactant systems are the simplest biological membrane models that not only mimic the cell membrane functions but are also used to investigate the biophysical interactions between pharmaceutical drugs and bio-membranes at the molecular level. In this work, volumetric and acoustic studies were used to investigate the molecular interactions of moxifloxacin (MXF), a potential antibacterial drug, with ionic surfactants (dodecyl-tri-methyl-ammonium bromide (DTAB), a cationic surfactant and sodium dodecyl sulfate (SDS), an anionic surfactant) under physiological conditions (phosphate buffer, pH 7.4) at T = 298.15-313.15 K at an interval of 5 K. Various volumetric and acoustic parameters were computed from the density and sound speed data and interpreted in terms of MXF-ionic surfactant interaction using electrostriction effect and co-sphere overlap model. Absorption spectroscopy and cyclic voltammetry were further used to determine the binding, partitioning, and related free energies of MXF with ionic micelles.

A recent overview of surfactant-drug interactions and their importance

This review focuses on the self-aggregation properties of different drugs, as well as on their interaction with anionic, cationic, and gemini surfactants. The interaction of drugs with surfactants has been reviewed concerning conductivity, surface tension, viscosity, density, and UV-Vis spectrophotometric measurements, and their relation with critical micelle concentration (CMC), cloud point, and binding constant. The conductivity measurement technique is used for the micellization of ionic surfactants. Cloud point studies can be used for the non-ionic, and also for certain ionic surfactants. Usually, surface tension studies are mostly employed for non-ionic surfactants. The degree of dissociation that is determined is used to evaluate thermodynamic parameters of micellization at various temperatures. The effect of external parameters like temperature, salt, solvent, pH, etc., is discussed for thermodynamics parameters using recent experimental works on drug-surfactant interactions. Consequences of drug-surfactant interaction, condition of drugs during interaction with surfactants, and applications of drug-surfactant interaction are being generalized which reflects current and future potential uses of drug-surfactant interactions.

Designed electrochemical sensor based on metallocene modified conducting polymer composite for effective determination of tramadol in real samples

A novel composite for the electrochemical sensing of tramadol (Tr) was developed by the inclusion of a metallocene mediator between two layers of conducting poly(3,4-ethylenedioxythiophene) (PEDOT) polymer, in the presence of sodium dodecyl sulfate (SDS), i.e., P/mediator/P⋯SDS. Three charge transfer mediators were evaluated: ferrocene carboxylic acid (FC1), ferrocene (FC2), and cobaltocene (CC) for Tr electrocatalytic oxidation. The FC1 charge mediator showed a relatively higher current response that was assisted by the electronic conduction of the polymer film. Moreover, SDS presented a great impact, resulting in the enhancement of the preconcentration and (or) accumulation of Tr ions at the interface, leading to faster electron transfer. In addition, the practical application of the proposed FC1 composite for the determination of Tr in real urine and serum samples was successfully achieved with adequate recovery results. Very low detection limits of 18.6 nM and 16 nM in the linear dynamic ranges of 7–300 µM and 5–280 µM, respectively, were obtained at the proposed sensor. Furthermore, the simultaneous determination of Tr with common interfering species, paracetamol (APAP), morphine (MO), dopamine (DA), ascorbic acid (AA) and uric acid (UA), proved excellent, with good resolution and large potential peaks separation. The excellent characteristics of the proposed composite such as high reproducibility, good sensitivity, selectivity, anti-interference ability, and good stability enhanced its application for determination of other narcotic drugs.

Transbuccal Delivery of Isoniazid: Ex Vivo Permeability and Drug-Surfactant Interaction Studies

The oral administration of isoniazid (INH) may lead to discontinuation of tuberculosis treatment due to drug-related hepatotoxicity events, and thus, the transbuccal delivery of this drug was investigated, for the first time, as an alternative administration route. Ex vivo permeability assays were performed in Franz-type diffusion chambers, applying INH alone and in combination with sodium dodecyl sulfate (SDS) and sodium taurocholate (ST). After confirming the formation of micelle structures by dynamic light scattering analysis, UV-visible spectroscopy and zeta potential analyses were used to investigate drug-micelle interactions. In zeta potential analyses, no electrostatical interactions were identified for both surfactants in saliva buffer pH 6.8. Spectrophotometric analyses, in turn, indicated chemical interactions between INH and SDS in both pH values (2.0 and 6.8) whereas no interaction between the drug and ST was observed. Despite the interaction between SDS and drug, this surfactant increased the buccal transport rate of INH by approximately 11 times when compared with the control. In contrast, ST did not increase the drug permeability. The INH retention in SDS-treated mucosa was significantly higher when compared with the control and an effect on intercellular lipids was suggested. In vivo studies are needed to confirm the high INH absorption found here. Grapical abstract.

Electroanalysis of isoniazid and rifampicin: Role of nanomaterial electrode modifiers

Thanks to operational simplicity, speediness, possibility of miniaturization and real-time nature, electrochemical sensing is a supreme alternative for non-electrochemical methodologies in drug quantification. This review, highlights different nanotech-based sensory designs for electroanalysis of isoniazid and rifampicin, the most important medicines for patients with tuberculosis. We first, concisely mention analyses with bare electrodes, associated impediments and inspected possible strategies and then critically review the last two decades works with focus on different nano-scaled electrode modifiers. We organized and described the materials engaged in several categories: Surfactants modifiers, polymeric modifiers, metallic nanomaterials, carbon based nano-modifiers (reduced graphene oxide, multi-walled carbon nanotubes, ordered mesoporous carbon) and a large class of multifarious nano composites-based sensors and biosensors. The main drawbacks and superiorities associated with each array as well as the current trend in the areas is attempted to discuss. Summary of 79 employed electrochemical approaches for analysis of isoniazid and rifampicin has also been presented.

Role of Green Chemistry in Antipsychotics' Electrochemical Investigations Using a Nontoxic Modified Sensor in McIlvaine Buffer Solution

A new low-cost green electrochemical sensor based on nontoxic polyethylene glycol (PEG) and silver nanoparticles was used to improve the sensitivity of the carbon paste electrode for the investigation of olanzapine (OLZ) in dosage arrangements and in the existence of its coadministered drug fluoxetine and in the drug formulation. Scanning electron microscopy measurements were carried out to emphasize the morphology of the electrode surface. Cyclic voltammetry and differential pulse voltammetry were used to explore the diffusion and linearity behaviors of OLZ. Impedance spectroscopy measurements were determined to investigate the ac behavior of OLZ and then an ideal electrical circuit was modeled. A linear calibration was obtained from 1.0 × 10^-8 to 1.25 × 10^-4 M. The limit of detection was 1.5 × 10^-9 M, whereas the limit of quantification was 5 × 10^-9 M. The way has been wholly authenticated concerning linearity, precision, accuracy, reproducibility, sensitivity, and selectivity.

Electrochemical design of a new nanosensor based on cobalt nanoparticles, chitosan and MWCNT for the determination of daclatasvir: a hepatitis C antiviral drug

Daclatasvir (DAC) is listed on the World Health Organization's list of essential medicines needed in a basic health system, therefore, electrochemical and impedance spectroscopic methods are necessary.

Probing interactions of neurotransmitters with twin tailed anionic surfactant: A detailed physicochemical study

Keeping in view the role of neurotransmitters (NTs) in central nervous system diseases and in controlling various physiological processes, present study is aimed to study the binding of neurotransmitters (NTs) such as norepinephrine hydrochloride (NE) and serotonin hydrochloride (5-HT) with twin tailed surfactant sodium bis(2-ethylhexyl)sulfosuccinate (AOT). Spectroscopic and electrochemical measurements combined with microcalorimetric measurements were used to characterize the interactions between AOT and NTs. Meteoric modifications to emission profile and absorption spectra of NTs upon addition of AOT are indicative of the binding of NTs with AOT. Distinct interactional states such as formation of ion-pairs, induced and regular micelles with adsorbed NTs molecules have been observed in different concentration regimes of AOT. The formation of ion-pairs from oppositely charged NTs and AOT is confirmed by the reduced absorbance, quenched fluorescence intensity and decrease in peak current (ipa) as well as shifts in peak potential (Epa) values. The stoichiometry and formation of the NTs-AOT complexes has been judged and the extent of interactions is quantitatively discussed in terms of binding constant (K) and free energy of binding (ΔG°). The enthalpy (ΔH°mic) and free energy of micellization (ΔG°mic) for AOT in presence and absence of NTs are determined from the enthalpy curves.

Determination of sparfloxacin and besifloxacin hydrochlorides using gold nanoparticles modified carbon paste electrode in micellar medium

Determination of sparfloxacin and besifloxacin hydrochlorides using gold nanoparticles modified carbon paste electrode in micellar medium AuCPE was used to study the electrochemical behavior of SPAR and BESI using CV and DPV in presence of SDS.

A novel methionine/palladium nanoparticle modified carbon paste electrode for simultaneous determination of three antiparkinson drugs

A simple and novel method for the simultaneous determination of entacapone (EN), levodopa (LD) and carbidopa (CD) based on a methionine/palladium nanoparticle modified carbon paste electrode is described.

Determination of morphine at gold nanoparticles/Nafion® carbon paste modified sensor electrode

A novel and effective electrochemical sensor for the determination of morphine (MO) in 0.04 mol L(-1) universal buffer solution (pH 7.4) is introduced using gold nanoparticles electrodeposited on a Nafion modified carbon paste electrode. The effect of various experimental parameters including pH, scan rate and accumulation time on the voltammetric response of MO was investigated. At the optimum conditions, the concentration of MO was determined using differential pulse voltammetry (DPV) in a linear range of 2.0 × 10(-7) to 2.6 × 10(-4) mol L(-1) with a correlation coefficient of 0.999, and a detection limit of 13.3 × 10(-10) mol L(-1), respectively. The effect of common interferences on the current response of morphine namely ascorbic acid (AA) and uric acid (UA) is studied. The modified electrode can be used for the determination of MO spiked into urine samples, and excellent recovery results were obtained.