Cyclodextrin Solutions Research Articles

The study of stabilizing food enzymes using b-cyclodextrins

Background: Today, biologically active additives, which contain hydrolytic enzymes (amylase, lipase, protease), are widely used in the digestive industry. These enzymes are often obtained from animal and vegetable raw materials, -for example, from the pancreas of a reindeer, the Fabricius bag of chickens, and Medusomyces Gisevii Lindau (Kombucha). However, in obtaining enzymes, the activity of amylase and lipase may decrease due to active forms --of proteases. Objective: The main goal of this research work was to evaluate the stabilizing effect of nanostructures–cyclodextrins on the activity of hydrolytic enzymes (protease, amylase, lipase) obtained from animal raw material (chicken bursa of Fabricius) and microorganism cultures (Kombucha). Identify the relationship at which the negative influence of external environmental factors is leveled and, as a result, enzymatic activity is maintained for a certain period of time. Methods: The protein concentration in the solution was determined using the Lowry method. A modified method by Rukhlyadiva was used to determine the amylolytic activity. The definition of lipolytic activity is based on modified Shibabi-Bishop method. To determine the amylolytic activity, a modified method by Rukhlyadiva was used. Results: The relationship between b-cyclodextrin and enzymes was determined, at which enzymatic activity is maintained for a certain period. Conclusion: Thus, cyclodextrins in solution stabilizes the activity of proteases, amylases, and lipases, which is of great practical importance in the food and pharmaceutical industries. Keywords: kombucha, pancreas, enzymes, amylase, lipase, protease, cyclodextrins

Thermodynamic and spectroscopic investigation of the molecular interactions among vitamin B5, calcium salt, and cyclodextrins in aqueous media

The pharmaceutical industry aims to enhance drug development processes by gaining a deeper understanding of the physiochemical properties of drug molecules. This study provides a comprehensive analysis of the volumetric and compressibility properties of the drug, calcium-D-pantothenate (CDP) in aqueous solutions of cyclodextrins (β-CD/HP-β-CD). By measuring the density and speed of sound, we have evaluated various parameters, including apparent molar volume, compressibility, and their corresponding infinite dilution parameters. In addition to this, positive transfer parameters such as ΔtrVs,φo and ΔtrKs,φo of solute provide insights into solute-co-solute and solute–solvent interactions. Also, Hepler’s constant offers valuable information on the structure-breaking characteristics of the studied drug in cyclodextrin medium. The decrease in molar conductance of the binary system after adding cyclodextrin supports our theoretical observation from volumetric and compressibility studies. Positive values of activation energy favor spontaneity and the solubilization process. Furthermore, the 1H NMR study demonstrates that the β-CD molecule interacts more strongly with CDP molecules as compared to HP-β-CD.

State transition of macroscopic supramolecular hydrogel by the host‐guest coverage effect

AbstractIn this work, a hydrophobic guest monomer containing adamant end‐group was synthesized and introduced into the acrylamide hydrogel system to prepare macroscopic guest hydrogel. The swelling, transparency, and mechanical properties of the guest hydrogels can be significantly changed by soaking the guest hydrogel into hydrophilic cyclodextrin solution because the hydrophobic guest groups were recognized and covered by the hydrophilic host molecules. In addition, the surface lubrication property could be adjusted by changing the proportion of acrylamide and adamantane monomers in the hydrogel system. More importantly, cyclodextrin can bind with adamantane through host‐guest interactions, enabling the adjustment of the hydrophilicity/hydrophobicity properties of the hydrogel system. By controlling the assembly time, the hydrogel with different lubrication behaviors can be obtained. The controllable surface friction that this specific binding of host‐guest interaction has broad application prospects in intelligent device, bionic lubrication and other fields.

Enhancement of bioavailability and anti-inflammatory activity of inotodiol through complexation with γ-cyclodextrin

The aims of the present study were to fabricate an inclusion complex of inotodiol (INO) with cyclodextrin (CD) and to evaluate its bioavailability and anti-inflammatory activity. Different types of cyclodextrins in DDW were employed as host molecules, and INO dissolved in ethanol was added to the CD solutions during ultra-sonication. DSC and FTIR results showed that INO was complexed only with γ-cyclodextrin (γ-CD) efficiently at a molar ratio of 1:3 (INO1/γ-CD3). Large mean particle size (261.4 nm), high polydispersity index (0.497), and bimodal size distribution of INO1/γ-CD3 resulted from the formation of large aggregates after the inclusion complex formation. Following oral administration at the dose of 1.0 mg/kg for INO1/γ-CD3 group and the 2.0 mg/kg for INO group in mouse, the maximum inotodiol plasma concentration (Cmax) and the relative area under curve (AUC per 1 mg/kg dose) were 2.6- and 4.96-fold higher, respectively, in the INO1/γ-CD3 group than in the INO group. Anti-inflammatory activity analysis of INO was conducted using RAW264.7 cells stimulated by lipopolysaccharide, and the repression effect of INO on pro-inflammatory cytokines was enhanced by the complexation with γ-CD. Our findings suggest that INO1/γ-CD3 can be a potent therapeutic formulation for the treatment of inflammatory diseases.

Study of the Structural Chemistry of the Inclusion Complexation of 4-Phenylbutyrate and Related Compounds with Cyclodextrins in Solution: Differences in Inclusion Mode with Cavity Size Dependency.

4-phenylbutyrate (PB) and structurally related compounds hold promise for treating many diseases, including cancers. However, pharmaceutical limitations, such as an unpleasant taste or poor aqueous solubility, impede their evaluation and clinical use. This study explores cyclodextrin (CD) complexation as a strategy to address these limitations. The structural chemistry of the CD complexes of these compounds was analyzed using phase solubility, nuclear magnetic resonance (NMR) spectroscopic techniques, and molecular modeling to inform the choice of CD for such application. The study revealed that PB and its shorter-chain derivative form 1:1 αCD complexes, while the longer-chain derivatives form 1:2 (guest:host) complexes. αCD includes the alkyl chain of the shorter-chain compounds, depositing the phenyl ring around its secondary rim, whereas two αCD molecules sandwich the phenyl ring in a secondary-to-secondary rim orientation for the longer-chain derivatives. βCD includes each compound to form 1:1 complexes, with their alkyl chains bent to varying degrees within the CD cavity. γCD includes two molecules of each compound to form 2:1 complexes, with both parallel and antiparallel orientations plausible. The study found that αCD is more suitable for overcoming the pharmaceutical drawbacks of PB and its shorter-chain derivative, while βCD is better for the longer-chain derivatives.

Interfacial Rheological and Emulsion Properties of Self-Assembled Cyclodextrin-Oil Inclusion Complexes.

To investigate the effect of the molecular size of alkanes and the cavity size of cyclodextrins (CDs) on the formation of interfacial host-guest inclusion complexes, the interfacial tension (IFT) of CD (α-CD, β-CD, γ-CD) solutions against oils (hexadecane, dodecylbenzene) was determined by interfacial dilational rheology measurements. The results show that the "space compatibility" between CDs and oil molecules is crucial for the formation of interface host-guest inclusion complexes. Hexadecane with a smaller molecular size can form host-guest inclusion complexes with small cavities of α-CD and β-CD, dodecylbenzene with a larger molecular size can form interfacial aggregates with the medium-sized cavity of β-CD easily, and the polycyclic aromatic hydrocarbon molecules in kerosene can form inclusion complexes with the large cavity of γ-CD. The formation of interfacial inclusion complexes leads to lower IFT values, higher interfacial dilational modulus, nonlinear IFT responses to the interface area oscillating, and skin-like films at the oil-water interface. What's more, the phase behavior of Pickering emulsions formed by CDs with different oils is explored, and the phenomena in alkane-CD emulsions are in line with the results in dilatation rheology. The interfacial active host-guest structure in the kerosene-γ-CD system improves the stability of the Pickering emulsion, which results in smaller emulsion droplets. This unique space compatibility characteristic is of great significance for the application of CDs in selective host-guest recognition, sensors, enhanced oil recovery, food industries, and local drug delivery.

Novel approach for downstream processing of phytosterol bioconversion

AbstractBACKGROUNDDownstream processing is an important part of industrial steroid biotechnology. The traditional recovery methods require significant amounts of the organic solvents which are associated with environmental risks. There is a need for environmentally friendly downstream processing which also may open the prospects for regeneration and repeated use of the costly materials.RESULTSMicrobial conversion of phytosterol to C17‐ketosteroids in methylated cyclodextrin (mCD) solutions was studied as a model bioprocess. Quantitative aspects of competitive complexation of mCD and natural β‐CD (β‐CD) with steroids were studied under different temperature modes and CD concentrations. The method of steroid recovery based on precipitation of insoluble β‐CD complexes ensured the complete isolation of androst‐4‐ene‐3,17‐dione, androsta‐1,4‐diene‐3,17‐dione, 9α‐hydroxyandrost‐4‐ene‐3,17‐dione, 20‐hydroxymethyl‐pregna‐1,4‐dien‐3‐one and 3β‐hydroxyandrost‐5‐en‐17‐one from aqueous media. Analysis of the 1H nuclear magnetic resonance (NMR) spectra showed a constant molar ratio of β‐CD to steroid equal to 2 in the obtained steroid β‐CD complexes. The extraction of the steroid from the β‐CD complex by small volumes of organic solvent provided a quantitative yield. The method developed ensures regeneration and repeated use of the mCDs without decrease of the basic bioconversion outputs, as was demonstrated in a series of phytosterol to androsta‐1,4‐diene‐3,17‐dione bioconversions by Mycolicibacterium neoaurum VKM Ac‐1816D.CONCLUSIONSDownstream processing based on manipulation of steroid solubility in aqueous cyclodextrin solutions is a promising alternative to traditional steroid extraction with organic solvents. This environmentally friendly approach ensures re‐use of materials without decrease in bioconversion outputs. © 2023 Society of Chemical Industry (SCI).

Supersaturation maintenance of carvedilol and chlorthalidone by cyclodextrin derivatives: Pronounced crystallization inhibition ability of methylated cyclodextrin

Cyclodextrin (CD) is used to solubilize poorly water-soluble drugs by inclusion complex formation. In this study, we investigated the effect of CD derivatives on stabilizing the supersaturation by inhibiting the crystallization of two poorly water-soluble drugs, carvedilol (CVD) and chlorthalidone (CLT). The phase solubility test showed that β-CD and γ-CD derivatives enhanced the solubility of CVD to a greater extent, whereas the solubility of CLT was enhanced more by β-CD derivatives. The solubilization efficacy of CD derivatives was dependent on the size fitness between the drug molecule and the CD cavity. In the drug crystallization induction time measurement, the same initial drug supersaturation ratio (S) was employed in all the CD solutions, and the methylated CD derivatives greatly outperformed unmethylated CD derivatives in stabilizing the supersaturation of both CVD and CLT. The crystallization inhibition strength of CD derivatives was strongly affected by the CD derivative substituent. Moreover, the calculated logarithm of octanol/water partition coefficients (log P) of CD derivatives showed a good correlation with drug crystallization inhibition ability. Thus, the high hydrophobicity of methylated CD plays an essential role in inhibiting crystallization. These findings can provide a valuable guide for selecting appropriate stabilizing agents for drug-supersaturation formulations.

Patterning of Hydrophilic and Hydrophobic Gold and Magnetite Nanoparticles by Dip Pen Nanolithography.

Nanoparticles offer unique physical and chemical properties. Dip pen nanolithography of nanoparticles enables versatile patterning and nanofabrication with potential application in electronics and sensing, but is not well studied yet. Herein, the patterned deposition of various nanoparticles onto unmodified silicon substrates is presented. It is shown that aqueous solutions of hydrophilic citrate and cyclodextrin functionalized gold nanoparticles as well as poly(acrylic) acid decorated magnetite nanoparticles are feasible for writing nanostructures. Both smaller and larger nanoparticles can be patterned. Hydrophobic oleylamine or n-dodecylamine capped gold nanoparticles and oleic acid decorated magnetite nanoparticles are deposited from toluene. Tip loading is carried out by dip-coating, and writing succeeds fast within 0.1s. Also, coating with longer tip dwell times, at different relative humidity and varying frequency are studied for deposition of nanoparticle clusters. The resulting feature size is between 300 and 1780nm as determined by scanning electron microscopy. Atomic force microscopy confirms that the heights of the deposited structures correspond to a single or double layer of nanoparticles. Higher writing speeds lead to smaller line thicknesses, offering possibilities to more complex structures. Dip pen nanolithography can hence be used to pattern nanoparticles on silicon substrates independent of the surface chemistry.

Chiral analysis of linear protonated dipeptides by complexing with Cyclodextrins using Ion-Mobility Mass-Spectrometry and DFT structural calculations

The functions and applications of dipeptides have been reported to possess unique characteristics compared to that of proteins or amino acids. Naturally occurring amino acids, except for glycine, are chiral molecules; thus, for each type of dipeptide there are four possible isomers. Isomeric structural analysis of dipeptides is important for measuring the quality of dipeptide products, as well as understanding their chemical and biological functions in humans. In the present study, a rapid and simple method for isomeric recognition of protonated dipeptides H-D/l-Phe-D/L-X-OH, where X = hydrophobic amino acids, including alanine (Ala), isoleucine (Ile), leucine (Leu), proline (Pro), tryptophan (Trp), valine (Val), phenylalanine (Phe), and methionine (Met), was developed and investigated. Mixed solutions of dipeptides and cyclodextrins (CDs) were prepared for the production of gas phase, non-covalent complex ions by electrospray ionization (ESI). Trapped ion-mobility mass spectrometry (TIMS-MS) was subsequently used to investigate the corresponding ion mobilities (IM). The TIMS and density functional theory (DFT) results showed that the chiral structure of different dipeptides can be distinguished by β-CD, which indicates that different isomeric complexes have different collision cross sections (CCSs) and spatial conformations. The relative content of isomeric dipeptides mixtures was also obtained in the ratio range from 10:1 to 1:10 to measure the detection limits. Our work provides a direct analytical method for determining isomeric dipeptides, which could potentially have wide applications in the field of chiral recognition.

Cyclodextrin-assisted dispersive liquid-liquid microextraction based on solidification of floating organic droplets coupled with HPLC for the determination of pyrethroid residues in cereals

AbstractA simple, rapid, and environmentally friendly sample preparation method for pyrethroids determination in cereals using cyclodextrin-assisted dispersive liquid-liquid microextraction based on solidification of floating organic droplets coupled with high-performance liquid chromatography was established. The cereal samples were extracted with acetonitrile, cleaned up, and concentrated by green extractant menthol via γ-cyclodextrin assisted extraction process. The extractant menthol dispersed as fine droplets in the cyclodextrin solution and then solidified at room temperature for efficient extraction and convenient collection. The optimized method provided good linearity in the range of 0.01–10 mg kg−1 with limits of detection of 3.5–9.5 μg kg−1. The fortified recoveries of three pyrethroids (i.e., lambda-cyhalothrin, deltamethrin, and bifenthrin) in four cereals (i.e., rice, wheat, maize, and millet) at three levels were in the range of 77.6–101.6% with relative standard deviations of 0.6–6.6%. Overall, the proposed method can be successfully applied for the determination of pyrethroids in cereals.

Electrospinning of Cyclodextrin-Oligolactide Derivatives.

The materials used for the preparation of electrospun mats exhibit a large variety. Among them, cyclodextrins (CDs) and their derivatives have received thorough attention. Herein, we focus on the preparation of electrospun fibers based on biodegradable cyclodextrin-oligolactide (CDLA) derivatives, which may be qualified as polymer-free cyclodextrin. CDLA was prepared by ring opening of L-lactide initiated by the β-cyclodextrin. A clear structural image of the high-purity CDLA product was proved by MALDI MS. Preparation of the electrospun mats was optimized by taking into consideration the electrospinning parameters such as applied voltage, needle-to-collector distance, flow rate, the concentration of cyclodextrin solutions, and solvent type. The obtained electrospun fibers were morphologically characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS). SEM allowed the optimization of the electrospinning process to obtain beadless fibers with submicronic diameters. Further analysis by TEM and SAXS revealed the inner structural features of the CDLA-based filaments. Our results showed that the high purity CDLA materials, structurally well-defined at the molecular level, are suitable for the preparation of electrospun mats by using dimethylformamide or a water/acetonitrile mixture as electrospinning solvents, similar to lower molecular weight commercial cyclodextrin derivatives.

Amorphization of cyclodextrins by spray drying for producing encapsulated functional gas powders for agri-food applications

Cyclodextrin (CD) powders are the most suitable solid matrices to encapsulate gases to produce gas powders in agri-food industries, where gases have been widely used to ensure processability, quality, functionality, safety, and stability of many products. The use of gases in powder form is much easier and safer than conventional means of gas utilization from pressurized cylinders or tanks. Gas powders are typically produced by crystallization from aqueous CD solutions under gas pressure, which is time consuming and results in low product yield. In amorphous structure, CD powders enable a rapid and 100% yield method to produce stable gas powders. However, most commercial CD powders exist in crystalline structure. In this review, we describe the amorphization of CD powders by spray drying, the properties of amorphous CD powders in comparison with its crystalline counterparts, gas encapsulation using amorphous CD powders, and applications of gas-CD powders in food and agriculture production.

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.

Modelling drug diffusion through unstirred water layers allows real-time quantification of free/loaded drug fractions and release kinetics from colloidal-based formulations

The correlation between in vivo and in vitro data is yet not sufficiently optimized to allow a significant reduction and replacement of animal testing in pharmaceutical development. One of the main reasons for this lies in the poor mechanistic understanding and interpretation of the physical mechanisms enabling formulation rely on for deploying the drug. One mechanism that still lacks a proper interpretation is the kinetics of drug release from nanocarriers. In this work, we investigate two different types of classical enabling formulations – i) cyclodextrin solutions and ii) liposomal dispersions – by a combination of an experimental method (i.e. UV–Vis localized spectroscopy) and mathematical modelling/numerical data fitting. With this approach, we are able to discriminate precisely between the amount of drug bound to nanocarriers or freely dissolved at any time point; in addition, we can precisely estimate the binding and diffusivity constants of all chemical species (free drug/bound drug). The results obtained should serve as the first milestone for the further development of reliable in vitro/in silico models for the prediction of in vivo drug bioavailability when enabling formulations are used.

In-line sample concentration in capillary electrophoresis by cyclodextrin to admicelle microextraction

Cyclodextrins (CDs) as a pseudophase in pseudophase-to-pseudophase microextraction (P2ME) in capillary zone electrophoresis (CZE) are proposed. In this P2ME mode called CD to admicelle ME, a long plug of dilute analyte solution prepared in cetyltrimethylammonium bromide (CTAB) at the critical micellar concentration was injected into the capillary. This formed CTAB admicelles at the interface between the solution and the negatively charged capillary surface, where the analytes were trapped. The injection of CD solution released the admicelles and the analytes from the capillary surface due to the formation of stable CD/CTAB inclusion complexes. The analytes are concentrated at the CD front during injection and voltage separation. Various neutral CDs were found to be effective for CD to admicelle ME. To implement this in-line sample concentration technique in CZE, CD concentration, sample injection time, and sample:CD solution injection ratio were optimized. The optimized conditions for five model anionic analytes, namely, 4-bromophenol, sulindac, sulfamethizole, 4-vinylbenzoic acid, and succinylsulfathiazole, were 20 mM α-CD in 20 mM sodium tetraborate (pH 9.2) solution, sample injection time of 370 s, and CD:sample injection ratio of 1:2. The sensitivity enhancement factors (SEFs) were between 112 and 168. The SEFs of sulindac and sulfamethizole in particular were similar to previously published off-line microextraction techniques, which are typically time-consuming. The calculated values of LOQ, intra-/inter-day (n = 6/n = 10, 3 days) repeatability, and linearity (R2) of CD to admicelle ME were 0.0125–0.05 µg/mL, 1.5–4.6%, 1.8–4.8%, and ≥0.999, respectively. Finally, the potential of CD to admicelle ME to the analysis of artificial urine samples was demonstrated.

Conformational changes in β-phosphorylated nitroxides – A powerful tool to probe host–guest interactions

The isotropic hyperfine coupling constants corresponding to nitrogen and phosphorous atoms of β-phosphorylated nitroxides are sensitive to the polarity sensed by these probes, and to local interactions determining a change in the molecular conformation of the probe. The β-phosphorylated nitroxides selected for this study exhibit very different solvent effects. In this article are presented results regarding the interaction of two cyclic and two non-cyclic β-phosphorylated nitroxides with cyclodextrins of different cavity size. In order to find the minimum concentration of cyclodextrin that determines a change in the EPR spectrum of the β-phosphorylated nitroxides, series of cyclodextrin solutions were prepared. The binding constants were of the 10–102 orders of magnitude. The reversibility of the association process was evidenced by competitive experiments with 1-adamantanol. The sensitivity of β-phosphorylated nitroxides to the interaction with cyclodextrins as a function of cavity size and concentration is translated in EPR spectra with different patterns. Starting from this observation, we exemplified that it is possible to discriminate between solutions containing one cyclodextrin and a mixture of cyclodextrins. As such, β-phosphorylated nitroxides can be used as analytical markers to provide information on the composition of cyclodextrin solutions.

Cyclodextrins and Drug Membrane Permeation: Thermodynamic Considerations

Cyclodextrins are hydrophilic oligosaccharides that can increase aqueous solubility of lipophilic drugs through formation of water-soluble drug/cyclodextrin complexes. Although the complexes are hydrophilic, and as such do not permeate biological membranes, the complexes are known to enhance drug permeation through lipophilic membranes and improve drug bioavailability after, for example, oral administration. However, it is not clear how cyclodextrins enhance the permeation. An artificial biomembrane (PermeaPad®) was used to study the effect of donor medium composition on drug permeation. It was observed that in aqueous solutions the hydrophilic cyclodextrins behave not like disperse systems but rather like organic cosolvents such as ethanol, increasing the solubility without having significant effect on the molecular mobility and ability of lipophilic drug molecules to partition into the lipophilic membrane. Also, that partition of dissolved drug molecules from the aqueous exterior into the membrane is at its maximum when their thermodynamic activity is at its maximum. In other words, that drug flux from aqueous cyclodextrin solutions through lipophilic membranes depends on both the concentration and the thermodynamic activity of dissolved drug. Maximum flux is obtained when both the drug concentration and thermodynamic activity of the dissolved drug molecules are at their maximum value.

Stabilization and solubilization of difluprednate in aqueous cyclodextrin solution and its characterization for ophthalmic delivery

Difluprednate is a synthetic glucocorticoid used for the treatment of postoperative inflammation and pain associated with endogenous uveitis. It is very lipophilic with limited aqueous solubility and stability. The only available marketed formulation is an oil-in-water ophthalmic emulsion that has many drawbacks. Cyclodextrin (CD) molecules are widely used to increase the solubility and stability of hydrophobic drugs through the formation of drug/CD complexes. This study aims to investigate degradation kinetics, stability and solubility of difluprednate in aqueous CD solutions in an effort to develop aqueous eye drop vehicle for ophthalmic delivery. Phase-solubility and kinetics studies were performed in presence of different CDs and polymers. Characterization of the drug/CD complexes was done using techniques like NMR, DSC, and FTIR. The results show that difluprednate has maximum stability at pH 5 in aqueous CD solution. HPγCD was found to be the best solubilizer and stabilizer among all the CDs tested. The stability was further improved with the combination of HPγCD and different polymers. Characterization of the difluprednate/HPγCD complex in solid and solution state confirmed the presence of a drug/CD complex. It was possible to solubilize 0.1% difluprednate using HPγCD and stabilize the drug using combination of CD and polymer in aqueous solution.

Plants from Urban Parks as Valuable Cosmetic Ingredients: Green Extraction, Chemical Composition and Activity

The research on the possibilities of using biowaste from urban green areas is scarce. In this work, four plants, widely distributed in urban parks in Central Europe (Lotus corniculatus, Medicago lupulina, Knautia arvensis and Plantago major) were extracted using eco-friendly solvents based either on aqueous cyclodextrin solutions (hydroxypropyl-β-cyclodextrin or γ-cyclodextrin) or natural deep eutectic solvents based on glycerol, betaine and glucose. Metal content was determined using total reflection X-ray fluorescence (TXRF). The content of selected metabolites was determined using UV-VIS spectrophotometric methods and HPLC. Skin-related bioactivity was assessed using tyrosinase and elastase inhibition assays. The selected plants contained metals beneficial for skin health, such as zinc and calcium, while having a low content of toxic heavy metals. The extracts contained the bioactive phenolics such as quercetin, kaempferol, luteolin and apigenin. L. corniculatus was the most potent tyrosinase inhibitor, while K. arvensis showed the most pronounced elastase inhibitory activity. The employed solvents actively contributed to the observed bioactivity. The results indicate that the biowaste obtained from urban parks represents an ecologically acceptable alternative to conventional cultivation for the preparation of ecologically acceptable, high-value cosmetic products.