Adsorption Of Drug Molecules Research Articles

Self-assembled belt[12]pyridine nanotube for the adsorption and removal of anti-TB drugs from wastewater

Environmental safety is a major concern of today's world, and it has attracted the attention of the scientific research community. The environment gets contaminated due to various toxic drugs and pharmaceutical toxins coming from different sources. Therefore, removing these toxins is necessary for making the environment greener and safer. Nanomaterials are excellent candidates for adsorption and removal of harmful materials due to their unique properties. Herein we have studied self-assembled nanotube based on belt[12]pyridine (2-(12BPy)) as an adsorbent for the removal of antituberculosis drugs i.e. isoniazid (INZ) and pyrazinamide (PZA). The adsorption ability is studied by considering the adsorption energy (Eads), non-covalent interaction index analysis (NCI), quantum theory of atoms in molecules (QTAIM), energy decomposition analysis (EDA), charge transfer via natural bond orbital analysis (NBO) and electron localization function (ELF), and dipole moment. The results indicate strong adsorption of selected drugs with self-assembled nanotube without altering the electronic properties. Recovery time of the complexes is also calculated to understand the regeneration of the nanotube. Results also demonstrate that van der Waals forces are major contributor in the adsorption of drug molecules within the nanotube. Our results indicate that belt[12]pyridine (2-(12BPy)) nanotube can be used as an adsorbent for the removal of toxic drug molecules from the environment. This research will benefit the scientists working in the field of new sensors for biological components and materials.

Influence of Pyramidal M20 (M= Cu, Ag and Au) Clusters on SERS and Noncovalent Interactions toward Tuberculosis Drug Pretomanid (PTD): DFT Study

The study of interaction and adsorption of drug molecules on the active surface of noble metal nanocluster is of particular interest due to effective change in the properties of the drug molecules. Surface-enhanced Raman scattering (SERS) theoretical calculations were performed to investigate the adsorption properties of pretomanid (PTD) on pyramidal [Formula: see text]/[Formula: see text]/[Formula: see text] metal clusters. The charge transfer process from the [Formula: see text] pyramids is revealed by MEP and electronic analysis. The frequencies of PTD are enhanced in the PTD–metal complexes due to the noticeable SERS effect, and the binding energies were calculated to be −36.2 kcal/mol, −46.3 kcal/mol and −43.6 kcal/mol with Ag, Au and Cu structures, respectively. For the PTD–metal clusters, there is an entire potential rearrangement due to adsorption process which is due to charge transfer and adsorptions as chemisorption. The polarizability variations are predicted in the order PTD–Au > PTD–Cu > PTD–Ag which contribute the SERS enhancement due to adsorption. Changes in thermodynamic parameters reveal that adsorption is exothermic and at the same time spontaneous with ordered interactions due to the negative values. There is a redshift for the ultraviolet–visible (UV–vis) absorption of PTD–metal complexes with a lowering intensity in comparison with that of PTD, more likely indicating a chemisorption process. SERS enhancement factors are remarkable due to adsorption of conformationally flexible PTD on metal clusters. The noncovalent interactions between PTD and the metal pyramids were also determined. The study provided key information on designing a molecular structure with a good pharmacological profile by calculating bioactivity and drug similarity parameters for bioactive drug molecules.

The effect of Tetracycline drug as a green corrosion inhibitor for carbon steel in HCl media

Corrosion protection of metals, and alloys is a prime activity of technical, economic, environmental, and aesthetical significance. The use of inhibitors is oneof the best choice of combating metals, and alloys against detoriation against environmental impact. The toxicity of organic, and inorganic corrosion inhibitors to the environment has provoked the search for eco-friendly corrosion inhibitors like green corrosion inhibitors as other more environmental friendly corrosion inhibitors. This research demonstrates the anti-corrosion effect of Tetracycline drug on carbon steel alloy (ck45) in 1 M hydrochloric acid using electrochemical measurements (Tafel polarization and impedance spectroscopy (EIS) techniques). Also, the activation energy, the thermodynamic parameters and adsorption isotherm were derived from the electrochemical results. The highest inhibition yield for ck45 alloy in 1.0 M hydrochloric acid using 300 ppm of the drug is about 82% and 78% by polarization and EIS method, respectively. The potentiodynamic polarization measurement result shows that Tetracycline is a mixed-type inhibitor. The adsorption of drug molecules on the alloy surface obeying the Langmuir adsorption isotherm model and the ΔG°ads value calculated, suggested that the drug molecules adsorbed on the alloy surface via a physisorption mechanism. Also, optical microscopy and scanning electronic microscopy (SEM) studies, confirmed the formation of a protective film over the metal surface.

Betulinic acid and 3-o-acetyl-betulinic acid interactions with external and internal surface of boron-nitride nanotubes: A DFT and MD investigation

In present study, density-functional theory and molecular simulations were carried out to examine adsorption of anticancer drug betulinic acid and its analogue 3-o-acetyl-betulinic acid on external and internal surfaces of boron nitride nanotubes. To investigate effects of nanotube diameter and chirality on drugs adsorption, nanotubes including (8,8), (9,9), (10,10) and (16,0) were considered. Then, interactions of drugs with external and internal surfaces of these nanotubes were assessed. The results showed that both drugs are better adsorbed on internal nanotubes than on their external surface. Comparing energy amounts showed that adsorption energies are affected by nanotube diameter and both drugs molecules are adsorbed better on the internal nanotube (9,9) than (8,8) and (10,10). It was found that 3-o-acetyl-betulinic acid has stronger interaction with the boron nitride nanotubes internal surface. Results also showed that adsorption of drug molecules on nanotubes increases nanotubes polarity, which in turn improves solubility of nanotubes in water.

Study of volumetric, viscometric, and aggregation properties of losartan potassium and its interaction with amino acids and cetyltrimethylammonium bromide in aqueous solution

AbstractThis manuscript reports volumetric, viscometric, and aggregation properties of losartan potassium (LP) in aqueous medium and its interaction with a cationic surfactant (cetyltrimethylammonium bromide [CTAB]). Densities of drug solutions were used to calculate apparent molar volumes while constants of Jones–Dole equation were calculated from viscosity measurements. By measuring surface tension, refractive index, and electrical conductivity of drug solutions, critical micelle concentration (CMC) of drug was determined, and calculation of surface excess concentration, free energy change of adsorption, free energy change, entropy change, and enthalpy change of micellization was carried out. UV/Visible spectroscopic data were used to get an understanding about the interaction of drug with cationic surfactant (CTAB). This interaction gives an idea about the interaction of drug with biomembrane as micelles of surfactant are similar to membranes in structure. The data were also used to calculate different important parameters for drug–surfactant interaction such as partition coefficient and binding constant. Moreover, two amino acids (glycine and l‐tryptophan) were used in solutions of drug separately to change its CMC. The results from volumetric and viscometric studies showed that the presence of drug in solution resulted in more organization of solvent molecules due to hydrophobic interaction. From the values of ∆G°ads and ∆G°m, it was concluded that the adsorption of drug molecules at solution–air interface and formation of micelles occurred spontaneously. A strong drug‐surfactant (LP–CTAB) interaction was observed by the attachment of drug molecules onto micellar surface of surfactant. The presence of amino acids in the solution of drug caused a decrease in the CMC of LP.

Using molecular dynamics simulation to explore the binding of the three potent anticancer drugs sorafenib, streptozotocin, and sunitinib to functionalized carbon nanotubes.

The adsorption of the anticancer drugs sorafenib (SF), streptozotocin (STZ), and sunitinib (STB) on pristine and functionalized carbon nanotubes (FCNTs, functionalized with valine or phenylalanine moieties) was investigated using molecular dynamics simulation. Descriptors such as the van der Waals (vdW) energy, the number of hydrogen bonds, and the radial distribution function were considered. It was found that the type of functional group on the nanotube is a key influence on the vdW interaction energy between a drug molecule and a nanotube. In addition, the positions of the functional groups on a nanotube are a key influence on the adsorption of drug molecules on its surface. Our study indicated that the adsorption of STZ on CNT/FCNTs involves a partial π-π interaction and hydrogen bonding, whereas SF and STB are adsorbed on CNT/FCNTs through π-π stacking and hydrogen bonding. Our results suggest that altering the functionalization of the nanotube surface can affect the drug-nanotube interaction. The results reported here should aid attempts to optimize the design of novel CNT-based drug carriers.

Hexagonal boron nitride nanosheet as novel drug delivery system for anticancer drugs: Insights from DFT calculations and molecular dynamics simulations

Density functional theory (DFT) calculations and molecular dynamic (MD) simulations were accomplished to comprehend the nature of the interactions between 5-fluorouracil (FU)/6-mercaptopurine (MP)/6-thioguanine (TG) anticancer drugs and hexagonal boron nitride (BN) nanosheet as a drug delivery system. It is found from the calculations that the adsorption process of drug molecules on the BN nanosheet is exothermic and occurs spontaneously. The polarity for the drug loaded complexes, offers the possibility of improving the condition of solubility, which is favorable for drug delivery in biological media. Orbital energy and density of state (DOS) calculations show that HOMO-LUMO energy gap of BN nanosheet decreases upon the adsorption of drug molecules. The quantum molecular descriptors show that the absorption of drugs on BN nanosheet increases the chemical reactivity. The results of the energy decomposition analysis (EDA) indicated that the dispersion interaction plays a predominant role in the stabilization of the drug-BN complexes. The intermolecular interactions were also investigated by the noncovalent interaction (NCI) and quantum theory of atoms in molecules (QTAIM) analyses. The MD results showed that the average of the interaction energy values in acidic conditions are lower (absolute values) than corresponding values obtained at neutral pH, which indicated the drug could be released within the target cancer cells. These findings contribute to the development of drug delivery systems based on BN nanosheet for delivery of anticancer drugs.

DFT and MD investigations on the functionalized boron nitride nanotube as an effective drug delivery carrier for Carmustine anticancer drug

In the present work, we apply density functional theory (DFT) calculations to investigate the drug delivery performance of the boron nitride nanotube (BNNT) having hydroxyl functional groups (-OH) for Carmustine (BCNU) agent in the gas phase and water environment. Based on the DFT results, it is found that the interaction between BCNU molecule and functionalized boron nitride nanotube (f-BNNT) is weak; so that, the adsorption of the BCNU drug on the nanotube surface is typically physisorption. Based on the structural characteristics, the stability of the BCNU/f-BNNT complexes contributed to the formation of the intermolecular hydrogen bonds (HBs) between the BCNU drug and hydroxyl groups of BNNT which confirmed by Bader theory of atoms in molecules (QTAIM) results. Our theoretical results show that the structural properties of BCNU molecule doesn't significantly change upon adsorption of drug molecule on f-BNNT. Moreover, the natural bond orbital (NBO) analysis show in BCNU/f-BNNT complexes, the charge transfers from f-BNNT to Carmustine drug and the electronic properties of BCNU drug are not affected during the adsorption process on the nanotube surface. Finally, the effects of drug concentration and temperature on the adsorption mechanism of BCNU molecules are investigated by molecular dynamics (MD) simulation. Such results provide valuable information on the potential applications of functionalized boron nitride nanotubes in the fields of drug delivery within biological systems.

Interaction of a Surface-Active Ionic Liquid with an Antidepressant Drug: Micellization and Spectroscopic Studies

The interaction of the antidepressant drug nortriptyline hydrochloride (NOT) with the surface-active ionic liquid (SAIL), 1-decyl-3-methylimidazolium chloride, [C10mim][Cl], has been studied using multiple techniques, including conductometric titration, tensiometric, fluorometric, dynamic light scattering and UV–visible spectrophotometric measurements. There is a significant decrease in the cmc of SAIL on the addition of the drug NOT, indicating adsorption of drug molecules in the outer portion of the micelle. In the present study, the values of the packing parameter, P, lie in the range of 0–0.3, which suggests that the micelles formed are spherical in nature. More negative values of the standard Gibbs energy of adsorption, $$ \Delta G_{\text{ad}}^{ \circ } $$ , compared to $$ \Delta G_{\text{m}}^{ \circ } $$ support our contention that adsorption of SAIL on the air-solution interface is relatively more favorable than its micellization in the presence of NOT. Fluorescence and DLS studies indicate that the aggregation number, Nagg, and hydrodynamic radius of SAIL increase with increase in concentration of NOT. The UV–visible spectroscopic study confirms the formation of a new complex between SAIL and NOT; this is also supported by the negative Gibbs energy of complexation.

Aggregation properties of levofloxacin in water and ethanol and its interaction with sodium dodecyl sulphate: A thermodynamic study

This manuscript reports the determination of critical micelle concentration (CMC) of levofloxacin (LF) in two solvents, water and ethanol, by using surface tension, refractive index and absorbance measurements. The data thus obtained were used to calculate different thermodynamic parameters for micellization process like free energy of micellization, free energy of adsorption, entropy and enthalpy of micellization. The interaction of this drug with anionic surfactant (SDS) was also studied using UV/Visible spectroscopy and conductometry. With rise in temperature, CMC of the drug was found to decrease in ethanol and increase in aqueous solution indicating dominance of lipophobic desolvation over lipophilic desolvation in ethanol and reverse, in case of aqueous solution. A strong drug/surfactant interaction was found to exist. The data obtained from drug/surfactant interaction were also used to find different interaction parameters like partition constant, free energy of partition, binding constant and free energy of binding which are very useful to understand the phenomenon of solubilization. Critical micelle concentration of levofloxacin increases with temperature in aqueous solution and decreases in ethanol. Processes of micellization and adsorption of drug molecules at solution-air interface are spontaneous and results in increase in entropy. The drug shows strong interaction with anionic surfactant (SDS) due to solubilization of drug molecules between ionic head groups of micelles of SDS.