Increased Water Solubility Research Articles

Hydroxylation and dechlorination of 3,3',4,4'-tetrachlorobiphenyl (CB77) by rat and human CYP1A1s and critical roles of amino acids composing their substrate-binding cavity.

Cytochrome P450 (CYP) monooxygenases play critical roles in determining the toxicity of polychlorinated biphenyls (PCBs) in mammals. Hydroxylation of PCBs by these enzymes leads to increased water solubility, promoting the elimination of PCBs from the body. The CYP1 family is mainly responsible for metabolizing PCBs that exhibit a dioxin-like toxicity. Although the dioxin-like PCB 3,3',4,4'-tetrachlorobiphenyl (CB77) is abundant in the environment and accumulates in organisms, information on CB77 metabolism by CYP1A1s is limited. In this study, recombinant rat CYP1A1 metabolized CB77 to 4'-hydroxy (OH)-3,3',4,5'-tetrachlorobiphenyl (CB79) and 4'-OH-3,3',4-trichlorobiphenyl (CB35), whereas human CYP1A1 produced only 4'-OH-CB79. Rat CYP1A1 exhibited much higher metabolizing activity than human CYP1A1 because CB77 was stably accommodated in the substrate-binding cavity of rat CYP1A1 and was close to its heme. In a rat CYP1A1 mutant with two human-type amino acids, the production of 4'-OH-CB79 decreased, whereas that of the dechlorinated metabolite 4'-OH-CB35 increased. These results are explained by a shift in the CB77 positions toward the heme. This study provides insight into the development of enzymes with high metabolizing activity and clarifies the structural basis of PCB metabolism, as dechlorination contributes to a drastic decrease in dioxin-like toxicity.

Potential Medical Applications of Chitooligosaccharides.

Chitooligosaccharides, also known as chitosan oligomers or chitooligomers, are made up of chitosan with a degree of polymerization (DP) that is less than 20 and an average molecular weight (MW) that is lower than 3.9 kDa. COS can be produced through enzymatic conversions using chitinases, physical and chemical applications, or a combination of these strategies. COS is of significant interest for pharmacological and medical applications due to its increased water solubility and non-toxicity, with a wide range of bioactivities, including antibacterial, anti-inflammatory, anti-obesity, neuroprotective, anticancer, and antioxidant effects. This review aims to outline the recent advances and potential applications of COS in various diseases and conditions based on the available literature, mainly from preclinical research. The prospects of further in vivo studies and translational research on COS in the medical field are highlighted.

Novel Organic Salts Based on Mefloquine: Synthesis, Solubility, Permeability, and In Vitro Activity against Mycobacterium tuberculosis.

The development of novel pharmaceutical tools to efficiently tackle tuberculosis is the order of the day due to the rapid development of resistant strains of Mycobacterium tuberculosis. Herein, we report novel potential formulations of a repurposed drug, the antimalarial mefloquine (MFL), which was combined with organic anions as chemical adjuvants. Eight mefloquine organic salts were obtained by ion metathesis reaction between mefloquine hydrochloride ([MFLH][Cl]) and several organic acid sodium salts in high yields. One of the salts, mefloquine mesylate ([MFLH][MsO]), presented increased water solubility in comparison with [MFLH][Cl]. Moreover, all salts with the exception of mefloquine docusate ([MFLH][AOT]) showed improved permeability and diffusion through synthetic membranes. Finally, in vitro activity studies against Mycobacterium tuberculosis revealed that these ionic formulations exhibited up to 1.5-times lower MIC values when compared with [MFLH][Cl], particularly mefloquine camphorsulfonates ([MFLH][(1R)-CSA], [MFLH][(1S)-CSA]) and mefloquine HEPES ([MFLH][HEPES]).

Molecular docking for rationalizing the use of linkers in polymer drug conjugates design for pegylated anti-inflammatory drug delivery

A smart linker is a crucial element throughout the creation of polymer-drug conjugates. It binds different portions or subunits altogether and may be freed by a suitable trigger, resulting in localized drug distribution and enhanced bioavailability. PEG (Polyethylene Glycol) linkers can be synthesized chemically by specifically adding functionalized groups with chemical reactivity at certain structural ends of PEG. Because they may integrate a diverse range of groups, PEG linkers are frequently utilized in molecular biology experiments due to increased water solubility, excellent biocompatibility, and non-immunogenicity. In present work, we have included various linkers which are incorporated in design of PDC’s (polymer drug conjugates) of pegylated NSAIDs (nonsteroidal anti-inflammatory drugs) through PEGylation. The main focus was to investigate the pharmacodynamic changes brought about by these linker’s conjugated to model drug Ibuprofen (IB1-IB7). The tools used for the analysis are Argus Lab 4.0 for molecular docking and pkCMS as ADMET prediction tool. The outcome of this work was, establishment of a method for choosing suitable linker for designing PDC’s for various NSAIDs and other bioactive agents.

Hydrochloride Salt of the GABAkine KRM-II-81.

Imidazodiazepine (5-(8-ethynyl-6-(pyridin-2-yl)-4H-benzo[f]imidazole[1,5-α][1,4]diazepin-3-yl) oxazole or KRM-II-81) is a potentiator of GABAA receptors (a GABAkine) undergoing preparation for clinical development. KRM-II-81 is active against many seizure and pain models in rodents, where it exhibits improved pharmacological properties over standard-of-care agents. Since salts can be utilized to create opportunities for increased solubility, enhanced absorption, and distribution, as well as for efficient methods of bulk synthesis, a hydrochloride salt of KRM-II-81 was prepared. KRM-II-81·HCl was produced from the free base with anhydrous hydrochloric acid. The formation of the monohydrochloride salt was confirmed by X-ray crystallography, as well as 1H NMR and 13C NMR analyses. High water solubility and a lower partition coefficient (octanol/water) were exhibited by KRM-II-81·HCl as compared to the free base. Oral administration of either KRM-II-81·HCl or the free base resulted in high concentrations in the brain and plasma of rats. Oral dosing in mice significantly increased the latency to both clonic and tonic convulsions and decreased pentylenetetrazol-induced lethality. The increased water solubility of the HCl salt enables intravenous dosing and the potential for higher concentration formulations compared with the free base without impacting anticonvulsant potency. Thus, KRM-II-81·HCl adds an important new compound to facilitate the development of these imidazodiazepines for clinical evaluation.

Review: Hydrotropy as Prominent Approach for Enhancement of Aqueous Solubility of Drugs

Solubility is crucial element to achieve the desired drug absorption in the total pharmacological response. Low water solubility can considerably limit the medication efficacy, and to improve aqueous solubility, a variety of approaches are employed. The capacity which increases water solubility for particular drug can thus be a useful tool for enhancing efficiency and/or decreasing negative effects. This is true for parental administered, topically applied and orally consumed solutions. It is a difficult work for researchers and pharmaceutical scientist to use solubility features in bioavailability, pharmacological effect and solubility enhancement of diverse weakly soluble substance. Hydrotropy is one of the strategies for increasing solubility. The purpose of this paper is to examine the hydrotropy Solubilization technique and to highlight the mechanism and different prospective of this method.
 Keywords: Hydrotropy, mechanism, formation of hydrotropes, Solubility

Johnson Matthey expands presence in green hydrogen with stake in AEM electrolyzer pioneer, Enapter

Drug nanocrystals with a particle size of 10–100 nm are obtained from individual or mixed techniques. Different approaches such as bottom-up and top-down can be used to produce these drug nanocrystals. The pharmaceutical industry faces the challenge of poorly water-soluble drugs. Approximately 50% of pharmaceutical medicines are poorly water soluble. Major problems associated with drugs are low oral bioavailability and low saturation solubility. As the nanotechnology field grows, it has tremendous potential applications in the field of medicine. By increasing water solubility, researchers can safely increase the saturation solubility of drugs. Conventional approaches are used to tackle the problem of solubility by making salt as an active ingredient so that water solubility gets increased. However, this approach is not true in all the cases. Only few molecules get water soluble by this process. Drug molecules contain different heteroatoms, and as a result solubility is generally poor. The drug solubility can further be increased using microemulsion suspension technique. Researchers have been moving toward nanotechnology, in which a particle size range of 10–100 nm is called a nanocrystal. This improves drug solubility to a greater extent. Nanocrystal drug molecules can be taken orally and are injectable wherein 100% bioavailability can be achieved. Different techniques can be used to synthesize these nanocrystals, by which production of larger extent can be done for commercial usages.

The Overlooked Photochemistry of Iodine in Aqueous Suspensions of Fullerene Derivatives.

Fullerene’s low water solubility was a serious challenge to researchers aiming to harness their excellent photochemical properties for aqueous applications. Cationic functionalization of the fullerene cage provided the most effective approach to increase water solubility, but common synthesis practices inadvertently complicated the photochemistry of these systems by introducing iodide as a counterion. This problem was overlooked until recent work noted a potentiation effect which occurred when photosensitizers were used to inactivate microorganisms with added potassium iodide. In this work, several photochemical pathways were explored to determine the extent and underlying mechanisms of iodide’s interference in the photosensitization of singlet oxygen by cationic fulleropyrrolidinium ions and rose bengal. Triplet excited state sensitizer lifetimes were measured via laser flash photolysis to probe the role of I– in triplet sensitizer quenching. Singlet oxygen production rates were compared across sensitizers in the presence or absence of I–, SO42–, and other anions. 3,5-Dimethyl-1H-pyrazole was employed as a chemical probe for iodine radical species, such as I·, but none were observed in the photochemical systems. Molecular iodine and triiodide, however, were found in significant quantities when photosensitizers were irradiated in the presence of I– and O2. The formation of I2 in these photochemical systems calls into question the interpretations of prior studies that used I– as a counterion for photosensitizer materials. As an example, MS2 bacteriophages were inactivated here by cationic fullerenes with and without I– present, showing that I– moderately accelerated the MS2 deactivation, likely by producing I2. Production of I2 did not appear to be directly correlated with estimates of 1O2 concentration, suggesting that the relevant photochemical pathways are more complex than direct reactions between 1O2 and I– in the bulk solution. On the basis of the results here, iodine photochemistry may be underappreciated and misunderstood in other environmental systems.

Liquiritin-Hydroxypropyl-Beta-Cyclodextrin Inclusion Complex: Preparation, Characterization, Bioavailability and Antitumor Activity Evaluation

The pharmacological activities of liquiritin (LT) are greatly limited by its insolubility and low oral absorption. The purpose of this study was to prepare LT-hydroxypropyl-beta-cyclodextrin inclusion complex (LT-HP-β-CD) to increase water solubility, oral bioavailability and antitumor effect of LT. Herein, saturated aqueous solution method was applied to prepare the LT-HP-β-CD prior to characterization via scanning electron microscope (SEM), infrared radiation (IR) spectroscopy, X-ray diffraction analysis (XRD), and differential scanning calorimetry (DSC). Also, in vitro release and in vivo pharmacokinetics were evaluated. Moreover, the anti-tumor activity of the formulation was investigated in the A549 lung cancer cells. The results of SEM, IR, XRD and DSC showed that LT-HP-β-CD was successfully formulated. In vitro release and oral bioavailability of LT-HP-β-CD compared with the free LT was significantly higher. Successfully, antitumor effect of LT was remarkably enhanced by the preparation of LT-HP-β-CD. Altogether, the LT-HP-β-CD represents a potential carrier for enhancing the water solubility and oral bioavailability of LT coupled with antitumor activity enhancement.

A new photolabeling probe for efficient enrichment and deep profiling of cell surface membrane proteome by mass spectrometry

The cell surface membrane proteome is a class of proteins encoded by ∼25% of all protein-coding genes in living organisms and plays a key role in mediating communication between the cells and their surrounding environment. However, most cell surface membrane proteins (CSMPs) are naturally expressed at very low levels compared with intracellular proteins. The difficulties in their purification with high specificity further hinder the understanding of their structure and function. In this study, we developed a new photolabeling probe to achieve efficient tagging and facile enrichment of the CSMPs. The probe is composed of a lipid tail for cell surface localization, a polyethylene glycol (PEG) spacer for increased water solubility, two 4-(N-maleimido)benzophenone (MBP) groups for UV-active tagging of the CSMPs, and a biotin tag for subsequent isolation. Application of this photolabeling probe resulted in the successful enrichment and identification of 3098 annotated CSMPs in HT22 cells with close to 70% selectivity. The proposed photolabeling probe and enrichment strategy were demonstrated to be a powerful method for deep cell surface proteome profiling, representing one of the largest groups of current drug targets.

DEVELOPMENT AND CHARACTERIZATION OF PEGYLATED CAPECITABINE LIPOSOMAL FORMULATIONS WITH ANTICANCER ACTIVITY TOWARDS COLON CANCER

Objective: Capecitabine is widely used in colorectal cancer treatment and has first-pass metabolism problem. Despite of its promising anticancer potential, capecitabine has not been used due to its poor solubility in water. The purpose of this study was to develop colon targeting capecitabine loaded stealth liposomes, which is a promising technique to avoid first-pass metabolism to achieve the desired bioavailability profile, increased water solubility and sustained release. Methods: Thin film hydration method was used to prepare capecitabine stealth liposomes. Prepared liposomes were characterized for drug release kinetics, stability studies, cell viability studies to determine the cytotoxic effect and in vivo studies in mice bearing colon carcinoma for evaluation of antitumor potential. Results: In vitro releases of liposomes were best fitted in the Higuchi matrix kinetic model with an n value from 0.868-0.964, indicating non-fickian release diffusion. Stability data indicated that liposomes were stable for at least 06 mo at 5±3 ° C. inhibiting activity was increased and with a Significant improvement in AUC, MRT and t1/2 observed as 29.65±5.08, µg h/ml for Stealth liposomes compared with the pure capecitabine and the conventional liposomes. Conclusion: Results suggested that Capecitabine-loaded stealth liposomes can be an effective delivery system for targeting colon cancer.

Multifaceted Roles of cAMP Signaling in the Repair Process of Spinal Cord Injury and Related Combination Treatments.

Spinal cord injury (SCI) results in multiple pathophysiological processes, including blood–spinal cord barrier disruption, hemorrhage/ischemia, oxidative stress, neuroinflammation, scar formation, and demyelination. These responses eventually lead to severe tissue destruction and an inhibitory environment for neural regeneration.cAMP signaling is vital for neurite outgrowth and axonal guidance. Stimulating intracellular cAMP activity significantly promotes neuronal survival and axonal regrowth after SCI.However, neuronal cAMP levels in adult CNS are relatively low and will further decrease after injury. Targeting cAMP signaling has become a promising strategy for neural regeneration over the past two decades. Furthermore, studies have revealed that cAMP signaling is involved in the regulation of glial cell function in the microenvironment of SCI, including macrophages/microglia, reactive astrocytes, and oligodendrocytes. cAMP-elevating agents in the post-injury milieu increase the cAMP levels in both neurons and glial cells and facilitate injury repair through the interplay between neurons and glial cells and ultimately contribute to better morphological and functional outcomes. In recent years, combination treatments associated with cAMP signaling have been shown to exert synergistic effects on the recovery of SCI. Agents carried by nanoparticles exhibit increased water solubility and capacity to cross the blood–spinal cord barrier. Implanted bioscaffolds and injected hydrogels are potential carriers to release agents locally to avoid systemic side effects. Cell transplantation may provide permissive matrices to synergize with the cAMP-enhanced growth capacity of neurons. cAMP can also induce the oriented differentiation of transplanted neural stem/progenitor cells into neurons and increase the survival rate of cell grafts. Emerging progress focused on cAMP compartmentation provides researchers with new perspectives to understand the complexity of downstream signaling, which may facilitate the clinical translation of strategies targeting cAMP signaling for SCI repair.

Increase water solubility of Centellaasiatica extract by indigenous bioenhancers could improve oral bioavailability and disposition kinetics of triterpenoid glycosides in beagle dogs

A newly standardised extract of Centellaasiatica (Centell-S) with better water solubility than the previous standardised extract of C.asiatica (ECa 233) was developed, and pharmacokinetic profiles of bioactive triterpenoids were investigated in beagle dogs. The test substances were administered via intravenous or oral administration with single and multiple doses for 7 days. The concentrations of major bioactive triterpenoids, including madecassoside, asiaticoside, madecassic acid, and asiatic acid, in biological samples were measured by liquid chromatography–tandem mass spectrometry. The dogs in this study showed good tolerability to all test substances, based on the physical appearance and blood chemistry 24 h after dosing. The major bioactive triterpenoids found in systemic blood circulation were madecassoside, asiaticoside, and asiatic acid; the concentration of these components ranged from 1 to 10,000 µg/L after intravenous administration of 1.0 mg/kg Centell-S. Oral administration of 10 and 20 mg/kg Centell-S generated approximately twofold higher plasma levels of both madecassoside and asiaticoside compared with equivalent doses of ECa 233. In addition, there was an accumulation of triterpenoid glycosides after multiple oral administrations of Centell-S for 7 days, while triterpenic acids showed little tendency for accumulation. Beagles had good tolerability to both standardised extracts of C.asiatica, and showed a similar pattern of bioactive triterpenoids to humans. Centell-S increased oral bioavailability of major triterpenoid glycosides and can be further developed into a phytopharmaceutical product.

Study on the effects of combined processing of micro‐pulverization and extrusion on the physicochemical properties of oat bran

The utilization rate of oat bran was improved and wastage of resources was reduced using the micro-pulverization technology combined with extrusion in processing oat bran. The effects of micro-pulverization and extrusion treatment on the structure, color, physical and chemical properties, functional properties, and pasting properties of oat bran were evaluated via Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), colorimeter, and rapid viscosity analyzer (RVA). Results showed that the pulverization and extrusion did not produce new functional groups in the bran. However, both treatment methods could increase the content of soluble dietary fiber (SDF) and degree of starch gelatinization, reduce oil-holding capacity (OHC), and increase water solubility index (WSI). Micro-pulverization increased the brightness and slowly digestible starch (SDS) of the bran, reduced rapidly digestible starch (RDS), and enhanced the antioxidant capacity of oat bran. Conversely, extrusion reduced the brightness and antioxidant capacity of oat bran, increased RDS. And extrusion made the surface of the bran relatively flat and denatured the protein. This study provides a theoretical basis that enterprises involved in oat processing can refer to. According to different market needs, adopt appropriate processing methods to process oat bran in order to gain more oat bran products.

Synthesis, biological evaluation, pharmacokinetic studies and molecular docking of 4′′′-acetyl-delicaflavone as antitumor agents

Structural modification of natural products is the effective option to improve their pharmacological effects and drug properties. DLF is a lead compound of antitumor drug, which is a broad-spectrum, low toxic and high-efficient component isolated from Selaginella doederleinii Hieron by our research group. Here, we report the structural modification method of this component, and find that the acetylated product of C4′′′- OH (C4′′′-acetyl-delicaflavone, 4′′′ADLF) has better inhibitory effect on the selected cancer cell lines, including, lung, liver, colon and cervical cancer cell lines. Since the increased water solubility of 4′′′ADLF may lead to higher absorption rate and activity, we evaluate the pharmacodynamics in vitro and in vivo, and the pharmacokinetic of 4′′′ADLF. It shows that 4′′′ADLF inhibit the proliferation and induce cycle arrest in tumor cells, and had better anticancer activity and bioavailability than DLF.

Preparation and characterization of innovative electrospun nanofibers loaded with pharmaceutically applicable ionic liquids

Keeping up with cutting edge research in the field of drug delivery, the overall goal of this study was to develop innovative electrospun nanofibers loaded with ionic liquids (ILs) as active pharmaceutical ingredients (APIs). For the first time, a novel approach was examined by combining biocompatible polymer, poly (ethylene oxide) (PEO), and pharmaceutical ILs in an electrospinning process to develop nanofibers with high drug loading (up to 47%). Firstly, two well-known local anaesthetic drugs, lidocaine and procaine, were modified into ILs with the salicylate, forming lidocaine salicylate and procaine salicylate. Its dual-functional nature and increased water solubility for 4- to 10-fold depending on the drug used contribute to overcoming current hurdles encountered by APIs such as poor solubility, low bioavailability, and polymorphism of the solid-state. Nanofibers were formulated using solutions tested for density, viscosity, electrical conductivity, and small-angle X-ray scattering by varying PEO molecular weight and the PEO to IL mass ratio. Scanning electron microscopy showed the surface morphology of the obtained nanofibers, while Fourier transform infrared spectroscopy and differential scanning calorimetry confirmed IL in the nanofibers in an amorphous state. Thus, nanofibers with incorporated IL represent well-known drugs in the new form and a novel dermal application delivery system.

Characterizing the Drug-Release Enhancement Effect of Surfactants on Megestrol-Acetate-Loaded Granules.

In this study, the effect of Cremophor® RH 40 (CR 40) classic micelles and Soluplus® (SP) polymeric micelles were investigated on a novel granule-type drug-delivery system containing megestrolacetate (MGA). Using a risk assessment-based approach on the formulation via melt technology resulted in the formation of these granules, presented as the dosage, with proper particle size and flow characteristics. Due to the application of a eutectic carrier base composition, gentle process conditions were reached, retaining the crystalline structure of the carrier system and allowing for the proper distribution of MGA in the granules. The increased water solubility (0.111 mg/mL to 2.154 mg/mL), and the decreased nano particle size (102.27 nm) with uniform distribution (polydispersity index of 0.259) and colloid stability (zeta potential of −12.99 mV) resulted in SP polymeric micelles prevailing over CR 40 micelles in this gastric dissolution study, performed in biorelevant fasted and fed state drug-release media. Mathematical characterization and kinetic model fitting supported the fast drug-release mechanism of polymeric micelles over micelles. The value-added polymeric micelle-containing formulation developed can be successfully administered perorally and the enhanced drug release offers the possibility of greater drug absorption in the gastrointestinal tract.

Two Water-Soluble and Wash-Free Fluorogenic Probes for Specific Lighting Up Cancer Cell Membranes and Tumors.

The construction of microenvironment-sensitive probes with good cell membrane-targetability can reveal the fundamental properties of cell membranes. Herein, two polarity-sensitive probes, termed MEMs were reported for the first time to specifically light up cancer cell membranes. Both probes were designed with tetrahydroquinoxaline coumarin amide as the fluorophore, and quaternary ammonium groups were appended to increase water solubility and target cell membranes. In vitro studies showed that the fluorescence of both probes displayed strong polarity dependence and had a wide linear range to polarity (Δf). MEMs also displayed excellent cell membrane targeting ability and could long-term light up cell membranes with red fluorescence and a wash-free process. More excitingly, MEMs could specifically light up cancer cell membranes, revealing that cancer cells might have lower cell membrane polarity than normal cells. In vivo studies showed that MEMs could also effectively distinguish tumors from normal tissues. Overall, this work has not only developed two polarity-sensitive probes with good cell membrane targetability, but also provided new insights and methods for an in-depth understanding of cancer cells and cancer diagnosis.

A study of the effects of sodium alginate and sodium carboxymethyl cellulose on the growth of common duckweed (Lemna minor L.)

Sodium alginate (ALG) and sodium carboxymethyl cellulose (CMC) are two polysaccharides that have a wide range of applications, which could lead to accidental pollution of the environment, making the assessment of their potential ecotoxicity imperative. The present study assesses the effects of ALG and CMC on the growth response of common duckweed (Lemna minor L.). The results emphasize that both polysaccharides can be classified as practically nontoxic based on their EC50 values, with ALG having a relatively higher toxicity compared to CMC. It was also observed that high doses of 1, 5 and 10 mg mL-1 of the two polysaccharides produced growth inhibitory effects against common duckweed. The toxicity of biopolymers against common duckweed, measured as EC50 values, seems to be correlated to the hydrophobicity of the monomers building the polymer. The EC50 values increase linearly with increasing water solubility (log S) values and decrease linearly with the lipophilicity (log P) values.

Polymer Micro and Nanoparticles Containing B(III) Compounds as Emissive Soft Materials for Cargo Encapsulation and Temperature-Dependent Applications.

Polymer nanoparticles doped with fluorescent molecules are widely applied for biological assays, local temperature measurements, and other bioimaging applications, overcoming several critical drawbacks, such as dye toxicity, increased water solubility, and allowing imaging of dyes/drug delivery in water. In this work, some polymethylmethacrylate (PMMA), polyvinylpyrrolidone (PVP) and poly(styrene-butadiene-styrene) (SBS) based micro and nanoparticles with an average size of about 200 nm and encapsulating B(III) compounds have been prepared via the reprecipitation method by using tetrahydrofuran as the oil phase and water. The compounds are highly hydrophobic, but their encapsulation into a polymer matrix allows obtaining stable colloidal dispersions in water (3.39 µM) that maintain the photophysical behavior of these dyes. Although thermally activated non-radiative processes occur by increasing temperature from 25 to 80 °C, the colloidal suspension of the B(III) particles continues to emit greenish light (λ = 509 nm) at high temperatures. When samples are cooling back to room temperature, the emission is restored, being reversible. A probe of concept drug delivery study was conducted using coumarin 6 as a prototype of a hydrophobic drug.