Concentrations Of Β-cyclodextrin Research Articles

Formulation, Characterization, and Evaluation of β-Cyclodextrin Functionalized Hypericin Loaded Nanocarriers.

St. John's wort in western Europe has been extensively utilized for the treatment of mild to moderate depression. Hypericin, a red pigment, is found to be responsible for its antidepressant activity. The aim of the current study was to prepare a nanoemulsion (O/W) of hypericin designed for immediate delivery of the drug to the brain for the treatment of depression. The nanoemulsion was prepared by means of a homogenization technique, and that was followed by its physicochemical evaluation. Tween-80, Span-80, β-cyclodextrin, ethanol, and eucalyptus oil were utilized for the manufacturing of the nanoemulsion. Morphological studies have revealed globular structures of nanosize that were confirmed by the zeta analysis. The consistency of particles was revealed by the low polydispersity values. pH values of all formulations lay within the range of nasal pH. The viscosity of the prepared formulations was affected by the increase in concentrations of β-cyclodextrin. After passing from the centrifugation and freeze-thaw studies, the prepared formulations showed good stability. Formulation F2 having a composition of oil phase (0.125 mL), aqueous phase (1.25 mL), and β-cyclodextrin (8%) showed the best results out of all the formulations, and F2 had a pH of 5.7, 5.35 cP viscosity, 1.332 refractive index, 148.8 globule size, and -10.8 zeta potential. The mean percentage drug release and in vitro and ex vivo percentage drug permeations were observed to be 71.75, 76, and 75.07%, respectively. Meanwhile, formulation F2 showed the maximum drug release and permeation. In vivo behavior studies including the open field test, elevated plus maze test, and tail suspension test were conducted to see the antidepressant effect of hypericin along with comparison with a commercially available treatment. In conclusion, the prepared formulation shows good efficacy as an antidepressant and can be considered as a natural alternative over synthetic drugs.

Preparation and Characterization of Disulfiram and Beta Cyclodextrin Inclusion Complexes for Potential Application in the Treatment of SARS-CoV-2 via Nebulization.

Disulfiram (DS), known as an anti-alcoholism drug, has shown a potent antiviral activity. Still, the potential clinical application of DS is limited by its low water solubility and rapid metabolism. Cyclodextrins (CDs) have been widely used to improve the solubility of drugs in water. In this study, five concentrations of hydroxypropyl β-cyclodextrin (HP) and sulfobutyl ether β-cyclodextrin (SBE) were used to form inclusion complexes of DS for enhanced solubility. Solutions were freeze-dried, and the interaction between DS and CD was characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). In addition, the nebulization properties of the DS–CD solutions were studied. The aqueous solubility of DS increased significantly when loaded to either of both CDs. The phase solubility of both complexes was a linear function of the CD concentration (AL type). Furthermore, physicochemical characterization studies showed a potent inclusion of the drug in the CD–DS complexes. Aerosolization studies demonstrated that these formulations are suitable for inhalation. Overall, the CD inclusion complexes have great potential for the enhancement of DS solubility. However, further studies are needed to assess the efficacy of DS–CD inclusion complexes against SARS-CoV-2 via nebulization.

Separation of dye from aqueous solution by a new gravity compression and aeration system

ABSTRACT Filtration is one of the important technologies for separating suspended particles. Under the condition of gravity compression, the filtration density can be increased and the separation effect of suspended particles can be improved. Considering the complex composition and the difficulty in degrading dye in industrial wastewater, a gravity compression aeration system with a modified polyester fibre ball (denoted as MPFB) was evaluated for the separation of dye from water. Congo red azo dye solution (0–40 mg/L) was selected as the model treatment compound. The MPFB was prepared by adjusting the concentrations of alkali (Quality score 0–25%), β-cyclodextrin (0∼80 g/L), reaction temperature (40–90°C), and silane coupler concentration (Concentration fractions 0–0.8%). We used Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) to characterise the MPFB. The separation was affected significantly by adsorption conditions such as MPFB dose and pH. The lower the MPFB dose, the higher the expected adsorption capacity. For the treatment of a dye solution at 500 mg/L, 100% removal was achieved with 48 g/L MPFB, at pH 8 during adsorption under non-circulation aeration. For 24 h of reaction, the system could reach the maximum adsorption capacity of 11.2 mg/g, which followed the pseudo-first order kinetics model and the intraparticle diffusion model. We discovered that circulation aeration provided the best adsorption and electrostatic and hydrogen bonding were the dominant components of adsorption. Overall, the system is a promising technology and has the potential to treat large volumes of dye wastewater.

Influence of β-cyclodextrin concentration on the physicochemical properties and skin permeation behavior of vitamin C-loaded Pickering water-in-oil-in-water (W1/O/W2) double emulsions

This study aimed at the influence of different concentrations of β-cyclodextrin (β-CD) (or complexes of β-CD and Tween 80) on the physical and chemical properties of vitamin C-loaded Pickering water-in-oil-in-water (W1/O/W2) double emulsions. The results showed that the use of higher concentrations of β-CD (or β-CD/Tween 80 complexes) can lead to the formation of emulsions with smaller droplet size, more elastic (gel-like) behavior, higher encapsulation efficiency and loading capacity, better physicochemical stability, and slower rate of drug release. Moreover, higher skin permeation and retention of vitamin C from Pickering W1/O/W2 double emulsions were observed with higher quantities of β-CD (or β-CD/Tween 80 complexes). The overall results revealed that the physicochemical properties of the vitamin C-loaded Pickering W1/O/W2 double emulsions could be effectively improved by the presence of β-CD/Tween 80 complexes, and such emulsion systems could be considered as a promising carrier for topical application of vitamin C.

Chiral separation of catechin and epicatechin by reversed phase high-performance liquid chromatography with β-cyclodextrin stepwise and linear gradient elution modes

Catechin and epicatechin were enantioseparated by high-performance liquid chromatography (HPLC) with a phenyl column and aqueous mobile phases containing 0.05% (w/v) and 0.6% (w/v) of β-cyclodextrin for catechin and epicatechin, respectively. β-Cyclodextrin was found to be scarcely retained on a phenyl column. Consequently, it was suggested that catechin, which was eluted earlier than epicatechin, formed more stable inclusion complex with β-cyclodextrin than epicatechin and earlier eluted enantiomers, (−)-catechin and (+)-epicatechin, formed more stable diastereomer complexes with β-cyclodextrin than the respective enantiomers. This was confirmed by β-cyclodextrin-modified micellar electrokinetic chromatography and Benesi−Hildebrand plots by fluorescence spectrophotometry. Effect of sugars (D-sucrose, D-glucose, and D-fructose) on the epimerization of (+)-catechin and (+)-epicatechin by heating was investigated by HPLC with a β-cyclodextrin stepwise elution mode, in which two kinds of aqueous eluents containing different concentrations of β-cyclodextrin were used by turns. The epimerization of the two enantiomers was suppressed only when D-fructose was added. Separation of ten kinds of catechins including catechin and epicatechin enantiomers was investigated by a β-cyclodextrin linear gradient HPLC elution mode without using organic solvents, where two kinds of aqueous eluents containing different concentrations of β-cyclodextrin were used with changing their ratio gradually. These catechins in a green tea infusion could be separated successfully by this method.

Formulation, Characterization, and In Vitro Drug Release Study of β-Cyclodextrin-Based Smart Hydrogels.

In this study, novel pH-responsive polymeric β-cyclodextrin-graft-poly(acrylic acid/itaconic acid) hydrogels were fabricated by the free radical polymerization technique. Various concentrations of β-cyclodextrin, acrylic acid, and itaconic acid were crosslinked by ethylene glycol dimethacrylate in the presence of ammonium persulfate. The crosslinked hydrogels were used for the controlled delivery of theophylline. Loading of theophylline was conducted by the absorption and diffusion method. The fabricated network of hydrogel was evaluated by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffractometry (XRD), and scanning electron microscopy (SEM). The crosslinking among hydrogel contents and drug loading by the fabricated hydrogel were confirmed by FTIR analysis, while TGA indicated a high thermal stability of the prepared hydrogel as compared to pure β-cyclodextrin and itaconic acid. The high thermal stability of the developed hydrogel indicated an increase in the thermal stability of β-cyclodextrin and itaconic acid after crosslinking. Similarly, a decrease in crystallinity of β-cyclodextrin and itaconic acid was observed after crosslinking, as evaluated by XRD analysis. SEM revealed an irregular and hard surface of the prepared hydrogel, which may be correlated with strong crosslinking among hydrogel contents. Crosslinked insoluble and uncrosslinked soluble fractions of hydrogel were evaluated by sol–gel analysis. An increase in gel fraction was seen with the increase in compositions of hydrogel contents, while a decrease in sol fraction was observed. Dynamic swelling and dissolution studies were performed in three various buffer solutions of pH 1.2, 4.6, and 7.4, respectively. Maximum swelling and drug release were observed at higher pH values as compared to the lower pH value due to the deprotonation and protonation of functional groups of the hydrogel contents; thus, the pH-sensitive nature of the fabricated hydrogel was demonstrated. Likewise, water penetration capability and polymer volume were evaluated by porosity and polymer volume studies. Increased incorporation of β-cyclodextrin, acrylic acid, and itaconic acid led to an increase in swelling, drug release, drug loading, and porosity of the fabricated hydrogel, whereas a decrease was detected with the increasing concentration of ethylene glycol dimethacrylate. Conclusively, the prepared hydrogel could be employed as a suitable and promising carrier for the controlled release of theophylline.

The Biological Fate of Pharmaceutical Excipient β-Cyclodextrin: Pharmacokinetics, Tissue Distribution, Excretion, and Metabolism of β-Cyclodextrin in Rats.

β-cyclodextrin has a unique annular hollow ultrastructure that allows encapsulation of various poorly water-soluble drugs in the resulting cavity, thereby increasing drug stability. As a bioactive molecule, the metabolism of β-cyclodextrin is mainly completed by the flora in the colon, which can interact with API. In this study, understanding the in vivo fate of β-cyclodextrin, a LC-MS/MS method was developed to facilitate simultaneous quantitative analysis of pharmaceutical excipient β-cyclodextrin and API dextromethorphan hydrobromide. The established method had been effectively used to study the pharmacokinetics, tissue distribution, excretion, and metabolism of β-cyclodextrin after oral administration in rats. Results showed that β-cyclodextrin was almost wholly removed from rat plasma within 36 h, and high concentrations of β-cyclodextrin distributed hastily to organs with increased blood flow velocities such as the spleen, liver, and kidney after administration. The excretion of intact β-cyclodextrin to urine and feces was lower than the administration dose. It can be speculated that β-cyclodextrin metabolized to maltodextrin, which was further metabolized, absorbed, and eventually discharged in the form of CO2 and H2O. Results proved that β-cyclodextrin, with relative low accumulation in the body, had good safety. The results will assist further study of the design and safety evaluation of adjuvant β-cyclodextrin and promote its clinical development.

Production of instant pomelo peel powder by spray drying: Optimization of wall material composition to microencapsulate phenolic compounds

Microencapsulation technique helps to protect the core materials from deterioration, thereby improving the bioavailability of active compounds. In microencapsulation, the wall properties determine the encapsulation efficiency, and better results can be achieved when a mixture of multiple wall materials is used. This study aimed to optimize the wall material composition of pomelo peel (Citrus maxima (Burn.) Merr.) microcapsules prepared by spray drying technology to achieve the best values of polyphenol recovery and encapsulation efficiency. Response surface methodology was employed and a Box-Behnken design was used to investigate the effects of four independent variables, including the concentrations of resistant maltodextrin, pectin, β-cyclodextrin, and gum arabic. The concentration of the feeding liquid, and spray drying inlet and outlet temperatures were fixed at 30 °Bx, 180 °C, and 65 °C, respectively. The results showed that the optimized wall material composition consisted of 52.66% maltodextrin, 0.92% pectin, 5.30% β-cyclodextrin, and 6.28% gum arabic. Using this formula, the polyphenol recovery yield was found to be 78.86%, while the encapsulation efficiency was 77.78%, which agreed well with the predicted values of 78.90% and 77.67%. These results strongly indicate that the optimized wall material composition proposed in this study may be beneficial in the encapsulation process.

Green synthesis of silver/carbon dot nanoparticles from Malva Sylvestris for fluorescence determination of tetracycline

In the present research, silver/carbon dot nanoparticles (Ag/CDs) were used for fluorescence determination of tetracycline (TC). For this purpose, extract of Malva with the scientific name of Malva Sylvestris from Malvaceae family with different medicinal properties and high nutritional value was used as the precursor for CDs synthesis and the reducing agent of silver ions through the hydrothermal method. The effect of synthesis parameters including AgNO3 and β-cyclodextrin concentrations, amount of extract, temperature, pH, and time were investigated on the preparation of Ag/CDs. The X-ray diffraction and energy-dispersive X-ray spectroscopy (EDS) confirmed the synthesis of Ag/CDs, and transmission electron microscopy (TEM) showed the construction of nanoparticles with an average size of 25 nm. The intensity of localized surface plasmon resonance (LSPR) absorption peak of silver nanoparticles was increased with addition of TC. In addition, with increasing the concentration of analyte, the fluorescence intensity of the Ag/CDs was enhanced due to metal enhanced fluorescence (MEF). By plotting the calibration curve using fluorescence data, the linear range of 0.025–3 ppm and the limit of detection of 0.6 μg L−1 (1.2 nM) were obtained for the method. To evaluate the practical performance of the sensor, the TC determination was carried out in human blood plasma and satisfactory results were obtained.

β-Cyclodextrin-containing chitosan-oligonucleotide nanoparticles improve insulin bioactivity, gut cellular permeation and glucose consumption.

The main objective of the present study was to develop a nanoparticulate drug delivery system that can protect insulin against harsh conditions in the gastrointestinal (GI) tract. The effects of the following employed techniques, including lyophilisation, cross-linking and nanoencapsulation, on the physicochemical properties of the formulation were investigated. We herein developed a nanocarrier via ionotropic gelation by using positively charged chitosan and negatively charged Dz13Scr. The lyophilised nanoparticles with optimal concentrations of tripolyphosphate (cross-linking agent) and β-cyclodextrin (stabilising agent) were characterised by using physical and cellular assays. The addition of cryoprotectants (1% sucrose) in lyophilisation improved the stability of nanoparticles, enhanced the encapsulation efficiency, and ameliorated the pre-mature release of insulin at acidic pH. The developed lyophilised nanoparticles did not display any cytotoxic effects in C2C12 and HT-29 cells. Glucose consumption assays showed that the bioactivity of entrapped insulin was maintained post-incubation in the enzymatic medium. Freeze-drying with appropriate cryoprotectant could conserve the physiochemical properties of the nanoparticles. The bioactivity of the entrapped insulin was maintained. The prepared nanoparticles could facilitate the permeation of insulin across the GI cell line.

High-Amylose Corn Starch/Konjac Glucomannan Composite Film: Reinforced by Incorporating β-Cyclodextrin

Glycerol-plasticized high-amylose corn starch/konjac glucomannan (HCS/KGM) composite films incorporated with various concentrations of β-cyclodextrin (β-CD) were prepared and investigated for structural, mechanical, and physical properties. The results of X-ray diffraction, attenuated total reflectance Fourier transform infrared spectroscopy, thermogravimetric analyses, and scanning electron microscopy indicated that β-CD excluded from the polymer chains and aggregated to form crystals during film formation, which drove HCS to interact with KGM more compactly. The thickness and transparency of the films increased after β-CD was incorporated. More associations of HCS/KGM enhanced the mechanical properties and reduced the moisture content of the films. The water vapor permeability of the HCS/KGM composite film was also improved significantly with the incorporation of β-CD. The enhanced association between biopolymers in the presence of β-CD will advance the development of a degradable active composite packaging film.

Host–guest inclusion complex of β-cyclodextrin and benzoic acid in water–ethanol solvents: spectroscopic and thermodynamic characterization of complex formation

In this study, an inclusion complex of benzoic acid with β-cyclodextrin (BA-βCD) was obtained from water–ethanol solvents. The yield of complex synthesis in binary mixtures is greater than in water and reaches maximum value at 0.10 mol fraction of ethanol. Results of FTIR spectroscopy analysis showed that the main difference in the spectra of the acid and inclusion complex was observed in the frequency ranging from 2500 to 3100 cm−1, corresponding to aromatic hydrogen vibrations. These vibrations are highly attenuated in complex. Phase solubility and differential scanning calorimetry studies revealed that the inclusion complex was obtained with 1:1 stoichiometric ratio and the solubility of benzoic acid increased with an increase in β-cyclodextrin concentrations in water. The logarithm of stability constant in water was found to be lgK = 1.99. The thermodynamic parameters for the reaction of (BA-βCD) complex formation in H2O–EtOH solvents were determined from calorimetric experiments carried out by means of the calorimetric titration system TAM III (TA Instruments) at T = 25 °C. The heat effects of mixing β-cyclodextrin solutions with benzoic acid were obtained from water–ethanol mixed solvents containing X(EtOH) = (0.00, 0.10, 0.20 and 0.30) mole fraction at pH = 3.6 and T = 25 °C. However, at X(EtOH) = 0.30 mol fraction, according to the calorimetric titration data, no complex formation occurs. When transferring from H2O to H2O–EtOH solvents, complex stability decreases from lgK = 2.4 to lgK = 0.7, wherein the reaction exothermicity increases from − 12.2 kJ mol−1 to − 44.3 kJ mol−1. An increase in the exothermicity of complexation is accompanied by a decrease in the entropic contribution to the change in the reaction Gibbs energy.

Triple Complexes of Bismuth Nanoparticles with β-Cyclodextrin and Polyvinylpyrrolidone

Ternary complexes of bismuth nanoparticles with β-cyclodextrin and polyvinylpyrrolidone are studied via UV and visible spectroscopy and dynamic light scattering. It is shown that, depending on the ratio of the concentrations of β-cyclodextrin to polyvinylpyrrolidone in a synthetic medium, bismuth nanoparticles can be stabilized sterically either by distributing polyvinylpyrrolidone molecules over the surface of a complex of nanoparticles with β-cyclodextrin or by forming inclusion complexes of nanoparticles in the hydrophobic cavity of β-cyclodextrin as a result of associated β-cyclodextrin molecules being pushed apart by polyvinylpyrrolidone molecules. The conditions are determined for the formation of ternary complexes that are aggregatively stable for 20 days and are characterized by a unimodal particle size distribution.

Effect of β-Cyclodextrin on the Quality of Wheat Flour Dough and Prebaked Bread

This work investigated the effects of the addition of different concentrations (0–3.0 wt%) of β-cyclodextrin (β-CD) on the properties of wheat dough and prebaked bread. Dough tensile test results and scanning electron microscopy revealed that the addition of 0.5–1.5 wt% β-CD enhanced dough tensile strength and promoted gluten formation. The addition of 2.0–3.0 wt% β-CD, however, failed to improve gluten network formation. Fourier transform infrared spectroscopy showed that the α-helix-to-β-sheet ratios of dough samples increased as β-CD content increased. This result indicated that the protein secondary structure of the dough had changed. Fermentation rheometry illustrated that dough fermentation height, gas production volume, and gas-holding capacity increased with the addition of 0–1.5 wt% β-CD. Dough fermentation capacity decreased when the addition of β-CD exceeded 2.0 wt%. The effect of β-CD on the quality of prebaked frozen bread was also studied. The results of texture profile analysis indicated that the addition of 1.5 wt% β-CD could reduce bread hardness and increase bread crumb elasticity and resilience. The results of the C-cell test further demonstrated that the addition of 1.5 wt% β-CD could increase stomatal number and decrease pore number and pore wall thickness. These characteristics suggested that the addition of β-CD improved bread structure.

Interaction of β-cyclodextrin with tosyl chloride in an aqueous alkaline medium

The regioselective functionalisation of the cyclodextrin matrix provides the possibility of purposefully altering the ability of cyclodextrins to form inclusion compounds, as well as to ensure their solubility, thus expanding the scope of their practical application [1, 2]. The most significant and promising trend in the selective modification of β-cyclodextrins consists in the preparation of tosyl derivatives, given that the substitution of such nucleophilic reagents as iodide, azide, thioacetate, hydroxylamine, alkylamide or polyalkylamide for the tosyl group results in the corresponding monosubstituted derivatives. In this study, we impl emented a method for the synthesis of mono-6-O-(p-toluenesulphonyl)-β-cyclodextrin, which was improved by β-cyclodextrin reacting with tosyl chloride in an aqueous medium in the presence of a base. The reaction of β-cyclodextrin with tosyl chloride in an aqueous alkaline medium produced a 58% yield of mono -6- O-(p-toluenesulphonyl)-β-cyclodextrin not requiring additional purification. The optimal concentrations of β-cyclodextrin and tosyl chloride were found to be 0.0032 mol/l and 0.0015 mol/l, respectively. It was shown that a decrease in the rate of filtering the unreacted tosyl chloride out of the reaction mixture is acc ompanied by an increase in the proportion of ditosyl derivatives and mono(3,6-anhydro)-β-cyclodextrin resulting from the intramolecular cyclisation of mono-6-O-(p-toluenesulphonyl)-β-cyclodextrin at room temperature under alkaline conditions. The structure of the obtained mono-6-O-(p-toluenesulphonyl)-β-cyclodextrin was confirmed using Proton NMR Spectroscopy. The proton NMR spectrum of the product resulting from the reaction of β-cyclodextrin with tosyl chloride contains signals corresponding to a tosyl radical: a singlet (2.42 ppm) and two doublets (7.41–7.43 ppm) produced by hydrogens of the benzene ring having radicals in the para position. Monosubstitution was confirmed by comparing the integrated intensities of signals produced by the protons of the cyclodextrin skeleton and the protons from the aromatic part of the reaction product. Their ratio indicated that only one of the seven primary hydroxyl groups of β-cyclodextrin was substituted.

Gold Nanoparticles with Immobilized β-cyclodextrin-capsaicin Inclusion Complex for Prolonged Capsaicin Release

Inclusion complexes of capsaicin with β-cyclodextrin (prepared at three different concentrations of β-cyclodextrin) were immobilized onto the surface of concentrated gold nanoparticles synthesized using the Frens method. Capsaicin release for 2 days into pure water and acetonitrile was recorded. The nanoparticles were characterized with absorbance spectra and transmission electron microscopy images. An inclusion complex without gold nanoparticles also displayed capsaicin release with a lag period of 1.5 days that suggested capsaicin release from gold nanoparticles was due to decomposition of the inclusion complex. Neither the inclusion complex nor the free capsaicin formed nanoparticles themselves. It was shown that physical immobilization of capsaicin onto the surface of gold nanoparticles without the aid of β-cyclodextrin did not lead to prolonged release. For comparison, inclusion complex encapsulation into chitosan nanoparticles was also carried out, but the release kinetics was less pronounced compared to that of gold nanoparticles.

Applying β-cyclodextrin to amaranth inoculated with white-rot fungus for more efficient remediation of soil co-contaminated with Cd and BDE-209

A pot experiment was conducted to investigate the effect of a series of β-cyclodextrin (β-CD) concentrations on bioremediation of soil co-contaminated with Cd and BDE-209 using amaranth and the white-rot fungus Phanerochaete chrysosporium, with BDE-209 degrading ability. Results showed that the white-rot fungus was beneficial to the growth of amaranth, Cd uptake and BDE-209 degradation. Addition of β-CD further increased biomass of both shoots and roots, shoot Cd concentrations and contents, chlorophyll concentrations and soil manganese peroxidase (MnP) activities. Furthermore, well-organized mesophyll cells were observed in β-CD treatments, implying that the combination of white-rot fungus and β-CD can alleviate the stresses of Cd and BDE-209 to mesophyll cells. The BDE-209 degradation rate was positively correlated to β-CD concentration and MnP activity in soil. Our results also revealed that RF+β0.8 treatment possessed the greatest Cd removal efficiency due to its well-configured mesophyll cells and the highest shoot biomass, chlorophyll concentration, and shoot Cd concentration. Considering simultaneous removal of Cd and BDE-209 from soil, using 0.8% β-CD to amaranth inoculated with white-rot fungus is a promising way forward for the phytoremediation of soil co-contaminated with Cd and BDE-209. A high percentage of mono-BDE was detected in inoculated amaranth, suggesting that BDE-209 was debrominated into low brominated PBDEs by the fungus in soil, which were then absorbed and further debrominated into mono-BDE in the plant.

Photophysics of Przewalskinone-B and its Binding Behavior with β- Cyclodextrin

The photophysical properties of Przewalskinone-B, a plant extract which is reported widely for its medicinal values were studied in the absence and presence of a drug carrier, β-Cyclodextrin. The steady state absorption, fluorescence excitation and emission spectra of Przewalskinone-B were studied in an aqueous medium. The fluorescence emission of Przewalskinone-B was analysed in presence of varying concentrations of β-Cyclodextrin in an alcohol/water medium. An appreciable quenching was observed in the emission intensity of Przewalskinone-B. There was also a red shift observed in both absorption and emission spectra in presence of β-Cyclodextrin which designated a convinced interaction between the two species.

Comparison of inhibitory effects of 17-AAG nanoparticles and free 17-AAG on HSP90 gene expression in breast cancer.

HSP90 may be overexpressed in cancer cells which are greatly dependent on Hsp90 function. Geldanamycin derivative 17 allylamino-17-demethoxygeldanamycin (17-AAG) inhibits the function and expression of HSP90. 17-AAG has poor water-solubility which is a potential problem for clinical practice. In this study for improving the stability and solubility of molecules in drug delivery systems we used a β-cyclodextrin- 17AAG complex. To assess cytotoxic effects of β-cyclodextrin-17AAG complexes and free 17AAG, colorimetric cell viability (MTT) assays were performed. Cells were treated with equal concentrations of β-cyclodextrin- 17AAG complex and free 17AAG and Hsp90 gene expression levels in the two groups was compared by real-time PCR. MTT assay confirmed that β-cyclodextrin- 17AAG complex enhanced 17AAG cytotoxicity and drug delivery in T47D breast cancer cells. The level of Hsp90 gene expression in cells treated with β-cyclodextrin- 17AAG complex was lower than that of cells treated with free 17AAG (P=0.001). The results demonstrated that β-cyclodextrin- 17AAG complexes are more effective than free 17AAG in down-regulating HSP90 expression due to enhanced β-cyclodextrin-17AAG uptake by cells. Therefore, β-cyclodextrin could be superior carrier for this kind of hydrophobic agent.

Nanoparticle formation of lycopene/β-cyclodextrin inclusion complex using supercritical antisolvent precipitation

With a view to promoting dispersion of lycopene in water, the precipitation of an inclusion complex of lycopene and β-cyclodextrin was investigated using the solution-enhanced dispersion by supercritical fluids (SEDS) process. The inclusion complex, which was prepared in N,N-dimethylformamide (DMF), was dissolved in the same solvent and then micronized by SEDS, using carbon dioxide (CO2) as a supercritical antisolvent. The effects of the initial concentrations of lycopene and β-cyclodextrin, the CO2 flow rate, the solution flow rate, and the pressure and temperature at which the process was conducted were examined. The morphologies of the resulting particles were observed by scanning electron microscopy (SEM) and field emission-scanning electron microscopy (FE-SEM). Small spherical particles were obtained at all operating conditions. At high pressure, high temperature, high CO2 flow rate and low solution flow rate, particles with an average particle size of about 40nm were obtained.