Inclusion complexes of azadirachtin with native and methylated cyclodextrins: solubilization and binding ability

Synthesis and Characterization of an Inclusion Complex of dl-Aminoglutethimide with β-Cyclodextrin and Its Innovative Application in a Biological System: Computational and Experimental Investigations

Our present study intended to investigate the encapsulation of DL-AGT within the lipophilic cavity of a β-CD molecule. The consequential inclusion system was characterized by UV-visible spectroscopy and ¹H NMR, PXRD, SEM, and FT-IR studies. Molecular docking was performed for the inclusion complex to discover the most proper orientation, and it was seen that the drug DL-AGT fits into the cavity of β-CD in a 1:1 ratio, which was also confirmed from the Job plot. Furthermore, a comparison was done on the basis of cell viability between the drug and its inclusion complex.

Fluorescence, FTIR and 1H NMR studies of the inclusion complexes of the painkiller lornoxicam with β-, γ-cyclodextrins and their hydroxy propyl derivatives in aqueous solutions at different pHs and in the solid state

Lornoxicam forms inclusion complexes with all cyclodextrins but for their hydroxy-propyl derivatives, the drug also interacts with their outer surfaces.

Painkiller Isoxicam and Its Copper Complex Can Form Inclusion Complexes with Different Cyclodextrins: A Fluorescence, Fourier Transform Infrared Spectroscopy, and Nuclear Magnetic Resonance Study

The interaction of a painkiller Isoxicam, belonging to the oxicam group of nonsteroidal anti-inflammatory drugs (NSAIDs) and its copper complex with different cyclodextrins (β-CD, γ-CD, HPβCD, and HPγCD), has been investigated in both solution and the solid state. Steady state and time-resolved fluorescence spectroscopy, fluorescence anisotropy, ¹H NMR, and FTIR spectroscopy are used. Both the drug and its copper complex form a host-guest inclusion complex with all CDs. Fluorescence spectroscopy is used to determine binding constants and stoichiometries of the host-guest complex. The strongest binding is seen for γ-CD. ¹H NMR study showed that Isoxicam penetrates into the CD cavity from the more accessible wider side. For β- and γ-CD, Isoxicam showed one type of binding, i.e., formation of an inclusion complex, whereas, for HPβCD and HPγCD, it showed two types of binding, i.e., inclusion in the CD cavities and interaction with the outer surface of the CD molecules mainly near the hydroxy propyl group. Deeper penetration occurred into the larger diameter cavity of γ-CD and HPγCD compared to β-CD and HPβCD. From FTIR and ¹H NMR study, it is seen that predominantly the π-electron-rich benzene part of the drug and its complex penetrate into the host cavity.

Efficiency of newly formulated camptothecin with β-cyclodextrin-EDTA-Fe3O4 nanoparticle-conjugated nanocarriers as an anti-colon cancer (HT29) drug

Camptothecin (CPT) is an anti-cancer drug that effectively treats various cancers, including colon cancer. However, poor solubility and other drawbacks have restricted its chemotherapeutic potential. To overcome these restrictions, CPT was encapsulated in CEF (cyclodextrin-EDTA-FE₃O₄), a composite nanoparticle of magnetic iron oxide (Fe₃O₄), and β-cyclodextrin was cross-linked with ethylenediaminetetraacetic acid (EDTA). This formulation improved CPT’s solubility and bioavailability for cancer cells. The use of magnetically responsive anti-cancer formulation is highly advantageous in cancer chemotherapy. The chemical characterisation of CPT-CEF was studied here. The ability of this nano-compound to induce apoptosis in HT29 colon cancer cells and A549 lung cancer cells was evaluated. The dose-dependent cytotoxicity of CPT-CEF was shown using MTT. Propidium iodide and Annexin V staining, mitochondrial membrane depolarisation (JC-1 dye), and caspase-3 activity were assayed to detect apoptosis in CPT-CEF-treated cancer cells. Cell cycle analysis also showed G1 phase arrest, which indicated possible synergistic effects of the nano-carrier. These study results show that CPT-CEF causes a dose-dependent cell viability reduction in HT29 and A549 cells and induces apoptosis in colon cancer cells via caspase-3 activation. These data strongly suggest that CPT could be used as a major nanocarrier for CPT to effectively treat colon cancer.

Subsistence of inclusion complex via assembly of a drug into cyclic oligosaccharide: Its formation, mechanism, behaviour and importance

The aim of this present work is to make soluble DEPM in aqueous medium through the formation inclusion complex into the hydrophobic hollow space of β-cyclodextrin (β-Cyd) which will provide a novel approach for designing drug delivery system in aqueous medium. The study of supramolecular complexation of DEPM with β-Cyd has been designed in both solution and solid state. In solution phase the evidences of the presence of non-covalent interactions in inclusion complex with 1:1 stoichiometry behaviour are obtained by investigating the UV-spectroscopy. The resultant solid of DEPM and β-Cyd is established by ¹H NMR, FTIR, powder XRD and SEM techniques. So, β-Cyd has the ability to encapsulate DEPM into their core without formation any covalent bonds and also increases the bioavailability of the water insoluble DEPM drug.

Magneto-chemotherapy for cervical cancer treatment with camptothecin loaded Fe3O4 functionalized β-cyclodextrin nanovehicle

We portray a novel way to synthesis of iron oxide magnetic nanoparticle incorporated β-cyclodextrin (β-CD) nanocarrier stabilized by ethylenediamine tetra acetic acid (EDTA) obtaining remarkable biocompatibility and biodegradability.

Inclusion of terpenes in cyclodextrins: Preparation, characterization and pharmacological approaches

Terpenes constitute the largest class of natural products and are important resources for the pharmaceutical, food and cosmetics industries. However, due to their low water solubility and poor bioavailability there has been a search for compounds that could improve their physicochemical properties. Cyclodextrins (natural and derived) have been proposed for this role and have been complexed with different types of terpenes. This complexation has been demonstrated by using analytical techniques for characterizing complexes such as DSC, NMR, XRD, FTIR, and TGA. The formation of inclusion complexes has been able to improve drug characteristics such as bioavailability, solubility and stability; and to enhance biological activity and efficacy. This review shows strong experimental evidence that cyclodextrins improve the pharmacological properties of terpenes, and therefore need to be recognized as being possible targets for clinical use.

Host–Guest Inclusion System of Luteolin with Polyamine-β-cyclodextrin: Preparation, Characterisation, Anti-oxidant and Anti-cancer Activity

The characterisation, inclusion complexation behaviours, and binding ability of inclusion complexes of luteolin (LU) with four polyamine-modified β-cyclodextrins (NH2-βCD, EN-βCD, DETA-βCD, TETA-βCD; where EN = ethylenediamine; DETA = diethylenediamine; TETA = triethylenetetramine) were investigated in both the solid and solution forms by photoluminescence spectroscopy, 1H and 2D NMR spectroscopy, differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy. The results showed that the water solubility, and the anti-oxidant activity and anti-cancer activity of LU were significantly increased in the inclusion complex with polyamine-β-cyclodextrin. The LU/CDs complex will be useful for its application as herbal medicine or healthcare product.

Ultrasound-assisted extraction of azadirachtin from dried entire fruits of Azadirachta indica A. Juss. (Meliaceae) and its determination by a validated HPLC-PDA method

Azadirachta indica A. Juss., also known as neem, is a Meliaceae family tree from India. It is globally known for the insecticidal properties of its limonoid tetranortriterpenoid derivatives, such as azadirachtin. This work aimed to optimize the azadirachtin ultrasound-assisted extraction (UAE) and validate the HPLC-PDA analytical method for the measurement of this marker in neem dried fruit extracts. Box-Behnken design and response surface methodology (RSM) were used to investigate the effect of process variables on the UAE. Three independent variables, including ethanol concentration (%, w/w), temperature (°C), and material-to-solvent ratio (gmL(-1)), were studied. The azadirachtin content (µgmL(-1)), i.e., dependent variable, was quantified by the HPLC-PDA analytical method. Isocratic reversed-phase chromatography was performed using acetonitrile/water (40:60), a flow of 1.0mLmin(-1), detection at 214nm, and C18 column (250×4.6mm(2), 5µm). The primary validation parameters were determined according to ICH guidelines and Brazilian legislation. The results demonstrated that the optimal UAE condition was obtained with ethanol concentration range of 75-80% (w/w), temperature of 30°C, and material-to-solvent ratio of 0.55gmL(-1). The HPLC-PDA analytical method proved to be simple, selective, linear, precise, accurate and robust. The experimental values of azadirachtin content under optimal UAE conditions were in good agreement with the RSM predicted values and were superior to the azadirachtin content of percolated extract. Such findings suggest that UAE is a more efficient extractive process in addition to being simple, fast, and inexpensive.

Host–Guest Inclusion System of Scutellarin with Polyamine-β-Cyclodextrin: Preparation, Characterisation, and Anti-cancer Activity

The inclusion complexation behaviours of scutellarin (SCU) with four polyamine-modified β-cyclodextrins (NH2-βCD, EN-βCD, DETA-βCD, and TETA-βCD; EN = ethylenediamine; DETA = diethylenetriamine; TETA = triethylenetetramine) have been investigated in both solution and solid state by photoluminescence spectroscopy, 1H and two-dimensional NMR spectroscopy, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy. The results showed that, with the increase in the number of amino groups, the hosts polyamine-modified β-cyclodextrins (NH2-βCD, EN-βCD, DETA-βCD, TETA-βCD) were able to solubilise SCU to higher levels than native β-CD (9.0 mg mL–1) up to 15.8, 20.4, 44.6, 50.7 mg mL–1 (calculated as SCU), respectively. Besides, the anti-tumour activity of SCU obviously increased after formation of the inclusion complexes. The SCU/CD complexes will be potentially useful for the design of a novel formulation of SCU for clinical treatment.

β-Cyclodextrin conjugated magnetic, fluorescent silica core-shell nanoparticles for biomedical applications

We present synthesis of highly uniform magnetic nanocomposite material possessing an assortment of important functionalities: magnetism, luminescence, cell-targeting, and hydrophobic drug delivery. Magnetic particle Fe3O4 is encapsulated within a shell of SiO2 that ensures biocompatibility of the nanocomposite as well as act as a host for fluorescent dye (FITC), cancer-targeting ligand (folic acid), and a hydrophobic drug storage-delivering vehicle (β-cyclodextrin). Our preliminary results suggest that such core-shell nanocomposite can be a smart theranostic candidate for simultaneous fluorescence imaging, magnetic manipulation, cancer cell-targeting and hydrophobic drug delivery.

Biodegradable polymer based encapsulation of neem oil nanoemulsion for controlled release of Aza-A

Azadirachtin a biological compound found in neem have medicinal and pesticidal properties. The present work reports on the encapsulation of neem oil nanoemulsion using sodium alginate (Na-Alg) by cross linking with glutaraldehyde. Starch and polyethylene glycol (PEG) were used as coating agents for smooth surface of beads. The SEM images showed beads exhibited nearly spherical shape. Swelling of the polymeric beads reduced with coating which in turn decreased the rate of release of Aza-A. Starch coated encapsulation of neem oil nanoemulsion was found to be effective when compared to PEG coated encapsulation of neem oil nanoemulsion. The release rate of neem Aza-A from the beads into an aqueous environment was analyzed by UV-visible spectrophotometer (214 nm). The encapsulated neem oil nanoemulsion have the potential for controlled release of Aza-A. Neem oil nanoemulsion encapsulated beads coated with PEG was found to be toxic in lymphocyte cells.

Advanced technologies for oral controlled release: cyclodextrins for oral controlled release

Cyclodextrins (CDs) are used in oral pharmaceutical formulations, by means of inclusion complexes formation, with the following advantages for the drugs: (1) solubility, dissolution rate, stability, and bioavailability enhancement; (2) to modify the drug release site and/or time profile; and (3) to reduce or prevent gastrointestinal side effects and unpleasant smell or taste, to prevent drug-drug or drug-additive interactions, or even to convert oil and liquid drugs into microcrystalline or amorphous powders. A more recent trend focuses on the use of CDs as nanocarriers, a strategy that aims to design versatile delivery systems that can encapsulate drugs with better physicochemical properties for oral delivery. Thus, the aim of this work was to review the applications of the CDs and their hydrophilic derivatives on the solubility enhancement of poorly water-soluble drugs in order to increase their dissolution rate and get immediate release, as well as their ability to control (to prolong or to delay) the release of drugs from solid dosage forms, either as complexes with the hydrophilic (e.g., as osmotic pumps) and/or hydrophobic CDs. New controlled delivery systems based on nanotechnology carriers (nanoparticles and conjugates) have also been reviewed.

Effects of fractionation and combinatorial evaluation of Tamarindus indica fractions for antibacterial activity

Six fractions, named TiA – TiF, were obtained by fractionating the crude ethanol extract of the stem bark of Tamarindus indica using column chromatographic techniques. On TLC, fraction TiB showed five bands, TiC three bands, while TiD and TiE showed two bands each. TiC, TiD and TiE were re-eluted with different solvent systems to yield two fractions each, while TiB yielded four. These subfractions were designated B1-B4; C1-C2; D1-D2 and E1-E2, respectively. Tannins, flavonoids and alkaloids, among other components, were detected, albeit in different proportions with respect to fractions and subfractions and were compartmentalized with respect to the solvent systems used. The in vitro antibacterial activity of fractions and subfractions was tested separately and in combinations using the agar well diffusion technique. The susceptibly of test strains (expressed as %) were: 83.3% (TiA and TiB), 75.0% (crude extract and TiC), 66.7% (TiD), 50.0% (TiE) and 16.7% (TiF) when used singly, whereas in combination, the corresponding susceptibilities were 100% (CE), 83.3% (DE), 66.7% (AB, AF, BC, BD, DE and EF), 50% (AC and CD), 33.3% (BE and BF) and 16.7% (AD) against Gram negative bacteria strains and 100% (EF), 80% (DE), 60% (AB, BC and CE), 40% (AC, BD, BF, CF and DF) and 20% (AE, AF, BE and CD) against Gram positive strains. Percentage susceptibility with combinatorial use of re-fractions ranged from 85.7–57.1% and 60–40% against Gram negative and positive strains (TiB subfractions), respectively, 100–85.7% and 40–0% against Gram negative and positive strains (TiC, TiD and TiE sub-fractions).

In vivo evaluation of the antiviral activity of Cajanus cajan on measles virus

Cajanus cajan, a tropical shrub, serves as source of food and traditional medicines. The evaluation of aqueous and ethanol extracts for activity against measles virus and toxicity to embryonated chicken eggs was carried out in this study. In vivo and in vitro assay techniques using embryonated chicken eggs and tissue culture (Hep-2 cell lines) as media for both virus cultivation and anti-virus assay showed that a hot-water extract yielded higher activity against measles virus. The hot-water extract of the stem yielded a Log(2) titre of 0.1 for the in vivo assay and an inhibition of cytopathic effect (CPE) in Hep-2 cells by 100% for the in vitro assay. At all concentrations of the extracts, there was a lowering of virus concentration (p = 0.05), indicated by hemagglutination (HA) titration, which is the advantage of HA titration over the tissue culture technique using CPE. This study validates embryonated chicken eggs as suitable media for anti-virus assay and the use of C. cajan in the treatment of some diseases of viral origin.

Host-guest system of nimbin and beta-cyclodextrin or its derivatives: preparation, characterization, inclusion mode, and solubilization

The inclusion complexation behavior, characterization, and binding ability of nimbin with beta-cyclodextrin (beta-CD) and its derivatives were investigated in both solution and the solid state by means of XRD, DSC, (1)H and 2D NMR, and UV-vis spectroscopy. The results showed that the water solubility and thermal stability of nimbin were obviously increased in the inclusion complex with cyclodextrins. This satisfactory water solubility and high thermal stability of the nimbin/CD complexes will be potentially useful for their application as herbal medicines or healthcare products.

The role of L-arginine in inclusion complexes of omeprazole with cyclodextrins

In this study, we investigate how the effect of L-arginine (ARG) and cyclodextrins upon omeprazole (OME) stability and solubility. The effect of the presence of ARG on the apparent stability constants (K(1:1)) of the inclusion complexes formed between OME and each cyclodextrin, beta-cyclodextrin (betaCD), and methyl-beta-cyclodextrin (MbetaCD) is studied by phase solubility diagrams and nuclear magnetic resonance (NMR) spectroscopy. The interaction of OME with those cyclodextrins, in the presence of ARG, is characterized using NMR spectroscopy and molecular dynamics simulations. ARG significantly increases the drug solubility and complex stability, in comparison to inclusion complexes formed in its absence. The effect is more pronounced for the OME:betaCD complex. ARG also contributes to a larger stability of OME when free in aqueous solution. The combination of ARG with cyclodextrins can represent an important tool to develop stable drug formulations.

Azadirachtin, a scientific gold mine

Azadirachtin is a highly interesting compound both for its chemical structure, which required 18 years to solve, and its synthesis, which required another 22 years, and for its biological properties as a feeding deterrent for many insects and a growth disruptant for most insects and many other arthropods. Its mode of action, structure-activity relationships, and its biosynthesis still require much research. A valuable natural pesticide, it has very low toxicity for vertebrates, and yet it has still not achieved a prominent place among pesticides and in many countries it is not yet licensed for use. An attempt is made to understand its failure to capture a larger market, 40 years after its discovery.

Improvement of antifungal activity of 10-undecyn-1-ol by inclusion complexation with cyclodextrin derivatives

The inclusion complexation behavior between 10-undecyn-1-ol and cyclodextrin (CD) derivatives, namely, randomly methylated beta-CD (RM-beta-CD) and hydroxypropyl-beta-CD (HP-beta-CD), was studied in terms of solubility improvement, apparent stability constant, and the inclusion ratios of the resultant inclusion complexes. The aqueous solubility of 10-undecyn-1-ol was greatly improved through complexation with the CD derivatives. RM-beta-CD is comparatively more efficient in solubilizing 10-undecyn-1-ol with an apparent stability constant outstripping that of HP-beta-CD by about an order of magnitude. Comparative in vitro evaluations of the growth inhibition effects of inclusion complex solutions toward Rosellinia necatrix, a phytopathogenic fungus, were performed. In comparison with the positive control, appreciable improvements of the antifungal activity of 10-undecyn-1-ol through the addition of CD derivatives were observed visually. The improvement was evaluated in terms of area covered by the mycelia of Rosellinia necatrix and their growth rate. RM-beta-CD was proven to be more effective compared to HP-beta-CD with regard to the reduction of both fungal mycelium-covered area and growth rate constant, presumably owing to greater solubility enhancement by RM-beta-CD and thus the bioavailability of 10-undecyn-1-ol. Inclusion complexation of 10-undecyn-1-ol with CD derivatives suggests a potential means for production of an environmentally friendly 10-undecyn-1-ol-based fungicide to counteract R. necatrix.

Secondary assembly of bile salts mediated by β-cyclodextrin–terbium(III) complex

A fluorescent cyclodextrin-Tb(III) complex is successfully synthesized and can include bile salts in its hydrophobic cavities. Therefore, it can efficiently induce the secondary assembly of small bile salt primary micelles to large micelle aggregates, and the aggregation process can be easily observed by transmission electron microscopy (TEM) and fluorescence microscopy.