Interaction of tetracaine hydrochloride with sodium deoxycholate in aqueous micellar phase and at the surface

Innovative approaches to cationic and anionic (catanionic) amphiphiles self-assemblies: Synthesis, properties, and industrial applications

Meeting the contemporary demand for the development of functional, biocompatible, and environment friendly self-assembled structures using efficient, cost-effective, and energy-saving methods, the field of colloids has witnessed a surge in interest. Research into cationic and anionic (catanionic) surfactant combinations has gained momentum due to their distinct advantages and synergistic properties in this context. Catanionic self-assemblies have emerged as promising contenders for addressing these requirements. Catanionic self-assemblies possess high stability, adjustable surface charge, and low critical aggregation concentration. This comprehensive review article distinguishes between cationic/anionic non-equimolar and equimolar ratio mixing formation of high-salt catanionic self-assemblies known as catanionic mixture and salt-free counterparts, termed ion-pair amphiphiles, respectively. It explores diverse synthesis techniques, emphasizing the roles of solvents, salts, and pH conditions and covers both experimental and theoretical aspects of state-of-the-art catanionic self-assemblies. Additionally, the review investigates the development of multi-responsive catanionic self-assemblies using light, pH, temperature, and redox, responsive cationic/anionic amphiphiles. It provides an in-depth exploration of potential synergistic interactions and properties, underscoring their practical importance in a wide range of industrial applications. The review explores challenges like precipitation, stability and identifies knowledge gaps, creating opportunities in the dynamic catanionic self-assembly field. It aims to offer insights into the journey of catanionic self-assemblies, from inception to current status, appealing to a broad audience invested in their scientific and industrial potential.

Interaction of Remalan Brilliant Blue R dye with n-alkyltrimethylammonium chloride surfactants: conductometric and spectroscopic investigations

Micellization behaviour, thermodynamics and dye-surfactant interactions are the main topics of this investigation into the relationship between Remalan Brilliant Blue R (RBBR) dye and n-alkyltrimethylammonium chloride (C n TAC; n = 12, 14, 16 and 18) surfactants. Conductometric analysis revealed that the critical micelle concentration decreased with increasing alkyl chain length, suggesting that longer chains formed better micelles. Due to electrostatic interactions, spectrophotometric analyses revealed notable alterations in RBBR absorption following contact with C n TAC. Benesi-Hildebrand and Scott equations were used to compute the binding constant (K b), which increased with chain length, indicating stronger dye-micelle interactions. The spontaneous interactions between RBBR and micelles were confirmed by thermodynamic analysis, which showed negative Gibbs free energy values (ΔG). The stability of dye-micelle complexes is attributed to hydrophobic forces, as seen by the greater negative ΔG that was produced by longer alkyl chains. Interestingly, increased surfactant concentrations changed equilibrium and decreased dye adsorption by breaking up pre-formed RBBR-C n TAC complexes. These results highlight how important the length of the alkyl chain is for micelle formation, thermodynamic parameters and dye-surfactant interactions. As the length of the chain grew, the sequence of RBBR binding strength was found to be C12TAC < C14TAC < C16TAC < C18TAC.

Effect of Cholic Acid Salt and Its Mixed Micelles on the Morphology of Giant Unilamellar Vesicles (GUV)

Bile salts, present in the gastrointestinal tract as biosurfactants, play a crucial role in emulsifying and solubilizing fat-soluble nutrients and drugs, thereby facilitating their absorption. However, the cellular permeation of bile acid-mixed micelles solubilized with lipophilic substances remains inadequately explored. To comprehend the cell permeation behavior of bile salts and their mixed micelles, giant unilamellar vesicles (GUVs) were employed as a cell-mimetic system, prepared with dioleylphosphatidylcholine (DOPC). Confocal laser scanning microscopy, utilizing fluorescent dyes doped in the lipid membrane and solubilized substances, was employed to observe morphological changes in GUVs subsequent to the application of sodium cholate (NaC) alone and NaC-mixed micelles solubilized with lipophilic components. In the case of NaC alone, below the critical micelle concentration (CMC), the monomer interacts with the lipid membrane of the GUV, inducing endocytic morphological changes that result in the formation of small vesicles containing the bulk liquid inside the GUV. Conversely, when both monomers and micelles interacted with the lipid membrane beyond the CMC, lipid aggregates such as buds and threads protruded outward from the GUV. Contrastingly, upon application of three types of NaC mixed micelles-NaC-P solubilized with Palmitoyloleoylphosphocholine (POPC), NaC-P-F solubilized with oleic acid (OA) and monoolein (MO), and NaC-P-P solubilized with perylene, a liposoluble dye-to the GUV, the lipid membranes formed aggregates or vesicles and migrated into the interior of the GUV. In the case of NaC-P and NaC-P-P, the coexistence of drawn lipid aggregates and solubilized substances was scarcely observed. In contrast, for NaC-P-F, the coexistence of solubilized substances was observed in both lipid aggregates and small vesicles that migrated into the GUV. It is suggested that the partitioning of the solubilized substance from the mixed micelles adsorbed on the GUV to the lipid bilayer is implicated in the permeation of the solubilized substance through the cell membrane.

Self-assembly of bile salts and their mixed aggregates as building blocks for smart aggregates

The present communication offers a comprehensive overview of the self-assembly of bile salts emphasizing their mixed smart aggregates with a variety of amphiphiles. Using an updated literature survey, we have explored the dissimilar interactions of bile salts with different types of surfactants, phospholipids, ionic liquids, drugs, and a variety of natural and synthetic polymers. While assembling this review, special attention was also provided to the potency of bile salts to alter the size/shape of aggregates formed by several amphiphiles to use these aggregates for solubility improvement of medicinally important compounds, active pharmaceutical ingredients, and also to develop their smart delivery vehicles. A fundamental understanding of bile salt mixed aggregates will enable the development of new strategies for improving the bioavailability of drugs solubilized in newly developed potential hosts and to formulate smart aggregates of desired morphology for specific targeted applications. It enriches our existing knowledge of the distinct interactions exerted in mixed systems of bile salts with variety of amphiphiles. By virtue of this, researchers can get innovative ideas to construct novel nanoaggregates from bile salts by incorporating various amphiphiles that serve as a building block for smart aggregates for their numerous industrial applications.

Amphiphilic Ionic Liquids Capable to Formulate Organized Systems in an Aqueous Solution, Designed by a Combination of Traditional Surfactants and Commercial Drugs

The present review describes the state of the art in the conversion of pharmaceutically active ingredients (API) in amphiphilic Ionic Liquids (ILs) as alternative drug delivery systems. In particular, we focus our attention on the compounds generated by ionic exchange and without original counterions which generate different systems in comparison with the simple mixtures. In water, these new amphiphiles show similar or even better properties as surfactants in comparison with their precursors. Cations such as 1-alkyl-3-methyl-imidazolium and anions such as dioctyl sulfosuccinate or sodium dodecyl sulfate appear as the amphiphilic components most studied. In conclusion, this work shows interesting information on several promissory compounds and they appear as an interesting challenge to extend the application of ILs in the medical field.

Investigation of Physiological Properties of Transglycosylated Stevia with Cationic Surfactant and Its Application To Enhance the Solubility of Rebamipide

The poor water solubility of rebamipide was enhanced by the mixed micelles of transglycosylated stevia (Stevia-G) and trimethylammonium chloride with varying carbon chain length (C _nTAC, n = 14, 16, and 18). Fluorometry, isothermal titration calorimetry (ITC) and dynamic light scattering techniques examined the aggregation properties of Stevia-G and C _nTAC. Synergism was found between Stevia-G and C _nTAC using the approaches of Clint and Rubingh. The negative interaction parameter (average β_m = -4.17, -5.47, and -7.07) and excess free energy (average ΔG°_ex = -2.47, -3.06, and -3.88 kJ mol^-1) increased with increasing chain length of C _nTAC. The negative B₁ values by the Maeda approach suggested that chain-chain interactions contribute to the formation of a mixed micelle. The solubilization of rebamipide in the mixed micelle was evaluated in the term of the molar solubilization ratio (MSR) and partition coefficient ( K_m). The K_m from the Stevia-G/C₁₆TAC system was highest at a low mole fraction of C _nTAC (0.2-0.6). In conclusion, the solubilization of rebamipide was more favorable between Stevia-G and C₁₆TAC, although the stability of the mixed micelle was enhanced by an increase in hydrophobicity of the longer chain lengths used in C _nTAC.

Unveiling the Aggregation Behavior of Doxorubicin Hydrochloride in Aqueous Solution of 1-Octyl-3-methylimidazolium Chloride and the Effect of Bile Salt on These Aggregates: A Microscopic Study

In this article, we have unveiled the aggregation behavior of a potent chemotherapeutic drug, doxorubicin hydrochloride (Dox) in a well-known imidazolium based surface active ionic liquid (SAIL), 1-octyl-3-methylimidazolium chloride (C₈mimCl). The aggregates formed by Dox in C₈mimCl have been characterized using dynamic light scattering (DLS), fluorescence lifetime imaging microscopy (FLIM), high-resolution transmission electron microscopy (HR-TEM), analytical transmission electron microscopy (analytical TEM), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and Fourier-transform infrared spectroscopy (FTIR) measurements. It is found that Dox forms large spherical aggregates in the presence of C₈mimCl SAIL. We have also explored the driving force behind this aggregation behavior of Dox in C₈mimCl. Furthermore, it is observed that in the presence of a common bile salt, sodium cholate (NaCh), Dox/C₈mimCl spherical aggregates disrupt to form rodlike fibrillar aggregates. Therefore, formation of spherical aggregates and also its disruption into rodlike fibrillar aggregates have been performed, and this is expected to open a new scope for the design of a new generation smart drug delivery system where the drug itself aggregates to form the delivery system.

Microstructural micellar transition in bile salt–ionic liquid mixed systems in water: a DLS and SANS study

Bile salt assisted morphological changes of ionic liquid micelles.