Solubilization of direct dyes in single and mixed surfactant system: A comparative study

Naturally sourced amphiphilic peptides as paclitaxel vehicles for breast cancer treatment

The marketed paclitaxel (PTX) formulation Taxol relies on the application of Cremophor EL as a solubilizer. The major drawback of Taxol is its hypersensitivity reactions and a pretreatment of anti-allergic drugs is a necessity. Therefore, developing an efficient and safe delivery vehicle is a solution to increase PTX treatment outcomes with minimal adverse effects. In this work, we prepared the amphiphilic peptides (termed AmP) from soybean proteins using a facile two-step method. AmP could efficiently solubilize PTX by self-assembling into mixed micelles with D-α-tocopherol polyethylene glycol succinate (TPGS), a common pharmaceutical expedient (PTX@TPGS-AmP). The intravenously administrated PTX@TPGS-AmP exhibited a slow clearance (0.24 mL·(min·kg)-1) and an enhanced AUC (41.4 μg.h/mL), manifesting a 3.6-fold increase compared to Taxol. In a murine 4T1 tumor model, PTX@TPGS-AmP displayed a superior antitumor effect over Taxol. Importantly, safety assessment showed a high biocompatibility of AmP and an i.v. dose up to 2500 mg/kg led to no observable abnormalities in the mice. In summary, the AmP presents a new green and easily-prepared amphiphilic biomaterial, with promising potential as a pharmaceutical excipient for drug delivery.

Recycled gold-reduced graphene oxide nanocomposite for efficient adsorption and photocatalytic degradation of crystal violet

In this study, gold-reduced graphene oxide (Au@rGO) nanocomposite has been synthesized by repurposing electronic waste and dry batteries. This innovative approach involved utilizing the graphite rod from dry batteries to produce reduced graphene oxide (rGO), which was subsequently modified through the incorporation of gold nanoparticles obtained from recycled electronic waste. This methodology marks a significant breakthrough in electronic waste recycling, presenting a cost-effective and sustainable means of creating novel nanocomposites for applications in photocatalysis and adsorption, particularly in the removal of crystal violet (CV) from aqueous media. The synthesized Au@rGO nanocomposite was characterized using X-ray diffraction, scanning electron microscopy, energy dispersed X-ray, and N2 adsorption/desorption. Parameters that affect the adsorption and photocatalytic degradation of CV dye have been studied in detail. The optimal conditions for CV adsorption and photocatalytic degradation were pH of 10, equilibrium time of 30 min, CV concentration of 10 mg/L and adsorbent dosage of 40 mg. Furthermore, the isotherm and kinetics of CV removal were also studied. The removal of CV dye using adsorption and photocatalytic degradation techniques reached 95% and 99%, respectively. Consequently, the results showed that photocatalytic degradation of CV dye onto the mesoporous Au@rGO nanocomposite is more proper way than the adsorption technique for removing the CV dye from aqueous media. The designed photocatalyst has high efficiency and it can be reused and activated several times so it can be used in real water treatment applications.

Unveiling the Role of Nonionic Surfactants in Enhancing Cefotaxime Drug Solubility: A UV-Visible Spectroscopic Investigation in Single and Mixed Micellar Formulations

This study reports the interfacial phenomenon of cefotaxime in combination with nonionic surfactants, Triton X-100 (TX-100) and Tween-80 (TW-80), and their mixed micellar formulations. Cefotaxime was enclosed in a micellar system to improve its solubility and effectiveness. TX-100 and TW-80 were used in an amphiphilic self-assembly process to create the micellar formulation. The effect of the addition of TX-100, a nonionic surfactant, on the ability of TW-80 to solubilize the drug was examined. The values of the critical micelle concentration (CMC) were determined via UV-Visible spectroscopy. Gibbs free energies (ΔGp and ΔGb), the partition coefficient (Kx), and the binding constant (Kb) were also computed. In a single micellar system, the partition coefficient (Kx) was found to be 33.78 × 106 and 2.78 × 106 in the presence of TX-100 and TW-80, respectively. In a mixed micellar system, the value of the partition coefficient for the CEF/TW-80 system is maximum (5.48 × 106) in the presence of 0.0019 mM of TX-100, which shows that TX-100 significantly enhances the solubilizing power of micelles. It has been demonstrated that these surfactants are effective in enhancing the solubility and bioavailability of therapeutic compounds. This study elaborates on the physicochemical characteristics and solubilization of reactive drugs in single and mixed micellar media. This investigation, conducted in the presence of surfactants, shows a large contribution to the binding process via both hydrogen bonding and hydrophobic interactions.

Effect of in situ mixed micellization of ester-functionalized gemini surfactant at different pHs on solubilization and cosolubilization of various polycyclic aromatic hydrocarbons of varying hydrophobicities

A pH controlled cleavability unfolds the 3-in-1 surfactant feature of an ester-bonded gemini surfactant, 2, 2'-[(oxybis (ethane-1,2-diyl))bis (oxy)]bis (N-hexadecyl-N,Ndimethyl-2-oxoethanaminium) dichloride (C16-C4O2-C16), by reinforcing in-situ mixed micellization between cleaved components at non-neutral pH (pH 3,12). The triplicity is assigned to two mixed-micelle variants at pH 3 and pH 12 besides the unhydrolyzed C16-C4O2-C16 at pH 7. The pH-controlled aggregation of such trichotomic surfactant dramatically enhances the micellar solubilization/cosolubilization of PAHs viz. naphthalene (Np), phenanthrene (Ph), pyrene (Py), perylene (Pe). The cosolubilization of binary/ternary PAH mixtures in such remarkable micellar assemblies at pH 3, 7 and 12 yields intriguing synergistic or antagonistic solubility outcomes correlated to PAH-PAH and PAH-micelle interactions. This study provides valuable insights into the potential applications of the ester-bonded gemini surfactant for the cosolubilization of undesirable hydrophobic compounds at natural sites having variable pH.

Solubilization of Reactive Red 2 in the Mixed Micelles of Cetylpyridinium Chloride and TX-114

Owing to their surface active properties, surfactants have numerous applications in different fields of life. In the present research work, the solubilization of reactive red 2 (RR2) has been studied in single and mixed micellar systems (MMS) using UV-visible spectroscopy and electrical conductivity measurements. The interaction of RR2 with ionic micelles of cetylpyridinium chloride (CPC) was investigated. In order to probe the interaction of RR2 in MMS, mixtures of CPC and TX-114 (Triton X-114, a nonionic surfactant) were used. UV-visible spectroscopy has been used to obtain the degree of solubilization of RR2 in terms of the partition coefficient (K_c) and Gibbs free energy of partitioning (ΔG^°_p). Electrical conductivity data have been employed to detect the critical micelle concentration (CMC) of the surfactant systems in the presence of RR2 and, accordingly, to calculate the thermodynamic parameters of the micellization. From the obtained data, it is concluded that the micellization is spontaneous at all studied temperatures. Moreover, the micellization was observed to be driven by both enthalpy and entropy. The results also indicated that MMS have better solubilizing power than single micellar solutions.

Interaction of Direct Blue 86 with cationic surfactant micelles: spectroscopic, conductometric and thermodynamic aspects

Due to the amphiphilic structure of surfactants, aqueous surfactant solutions can behave like very good solvents and dissolve both polar and non-polar solutes. This study reports on the solubilisation of a direct dye (Direct Blue 86) in a micellar medium using the cationic surfactant cetyltrimethylammonium bromide (CTAB). Solubilisation of dyes is important for their subsequent removal from aqueous media. UV spectroscopy and conductometry, among others, were used to quantitatively evaluate this process. The extent of solubilisation, the interaction between the molecules and the stability of the processes were checked using the partition coefficient (K x), the binding constant (K b) and the corresponding thermodynamic parameters. From the results, it could be concluded that the solubilisation of Direct Blue 86 is a spontaneous process supported by an increase in entropy. It was also found that the micellar medium CTAB is efficient for solubilisation and binding of the dye and can be used economically.

CMC determination using isothermal titration calorimetry for five industrially significant non-ionic surfactants

Surfactants are used in a vast array of products including pharmaceuticals, cosmetics and household formulations. From an industrial perspective, non-ionic surfactants are ideal for inclusion within such products as they are non-toxic, simple to formulate and economic to use. This study considers five non-ionic surfactants (Tween 20, Tween 80, Crodasol, Croduret and Etocas 35) to determine the critical micellar concentration (CMC) for each using isothermal titration calorimetry, thus avoiding issues regarding poor accuracy found with other techniques. Furthermore, this methodology has not previously been applied to this group of surfactants. For the most commonly used non-ionics (Tween 20 and Tween 80) a further study was undertaken to consider the influence of surfactant purity on the CMC determined, using standard grade (Tween 20 and 80), high purity (Tween 20 HP and Tween 80 HP) and Super Refined (SR PS20 and SR PS80). Results permitted calculation of the CMC for the surfactants whereupon the values were determined to range from 1.0 mM for Tween 20 HP to 2.9 mM for Tween 80 HP. Such information regarding the CMC event is useful from a formulation perspective as it can ensure that the most optimum concentration of surfactant is included within a formulation to maximize its efficacy.

Factors Affecting Synthetic Dye Adsorption; Desorption Studies: A Review of Results from the Last Five Years (2017-2021)

The primary, most obvious parameter indicating water quality is the color of the water. Not only can it be aesthetically disturbing, but it can also be an indicator of contamination. Clean, high-quality water is a valuable, essential asset. Of the available technologies for removing dyes, adsorption is the most used method due to its ease of use, cost-effectiveness, and high efficiency. The adsorption process is influenced by several parameters, which are the basis of all laboratories researching the optimum conditions. The main objective of this review is to provide up-to-date information on the most studied influencing factors. The effects of initial dye concentration, pH, adsorbent dosage, particle size and temperature are illustrated through examples from the last five years (2017-2021) of research. Moreover, general trends are drawn based on these findings. The removal time ranged from 5 min to 36 h (E = 100% was achieved within 5-60 min). In addition, nearly 80% efficiency can be achieved with just 0.05 g of adsorbent. It is important to reduce adsorbent particle size (with Φ decrease E = 8-99%). Among the dyes analyzed in this paper, Methylene Blue, Congo Red, Malachite Green, Crystal Violet were the most frequently studied. Our conclusions are based on previously published literature.