Enhancement of Dissolving Capacity and Reducing Gastric Mucosa Irritation by Complex Formation of Resibufogenin with β-Cyclodextrin or 2-Hydroxypropyl-β-cyclodextrin

Resibufogenin (RBG) is a natural medicinal ingredient with promising cardiac protection and antitumor activity. However, poor solubility and severe gastric mucosa irritation restrict its application in the pharmaceutical field. In this study, the inclusion complex of RBG with β-cyclodextrin (β-CD) and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) was prepared using the co-evaporation method, and the molar ratio of RBG to CD was determined to be approximately 1:2 by continuous variation plot for both CDs. The formation of inclusion complexes between RBG and each CD (RBG/β-CD and RBG/HP-β-CD) was evaluated by phase solubility study, Fourier transform infrared spectroscopy, and thin-layer chromatography. Powder X-ray diffraction and differential scanning calorimetry confirmed drug amorphization and encapsulation in the molecular cage for both CDs. Moreover, the inclusion complexes’ morphologies were observed using scanning electron microscopy. The dissolution rate of the inclusion complexes was markedly improved compared to that of RBG, and the complexes retained their antitumor activity, as shown in the in vitro cytotoxicity assay on a human lung adenocarcinoma cancer (A549) cell line. Moreover, less gastric mucosal irritation was observed for the inclusion complex. Thus, the inclusion complex should be considered a promising strategy for the delivery of poorly water-soluble anticancer agents, such as RBG.     

Preparation and Properties of Cyclodextrin Inclusion Complexes of Hyperoside

In order to improve the aqueous solubility and enhance the bioavailability of Hyperoside (Hyp), three inclusion complexes (ICs) of Hyp with 2-hydroxypropyl-β-cyclodextrin (2H-β-CD), β-cyclodextrin (β-CD), and methyl-β-cyclodextrin (M-β-CD) were prepared using the ultrasonic method. The characterization of the inclusion complexes (ICs) was achieved using Fourier-transform infrared spectroscopy (FTIR), scanning electronic microscopy (SEM), X-ray powder diffraction (XRPD), thin-layer chromatography (TLC), and ¹H nuclear magnetic resonance (¹H NMR). The effects of the ICs on the solubility and antioxidant activity of Hyp were investigated. A Job’s plot revealed that the Hyp formed ICs with three kinds of cyclodextrin (CD), all at a 1:1 stoichiometric ratio. The FTIR, SEM, XRPD, TLC, and ¹H NMR results confirmed the formation of inclusion complexes. The water solubility of the IC of Hyp with 2-hydroxypropyl-β-cyclodextrin was enhanced 9-fold compared to the solubility of the original Hyp. The antioxidant activity tests showed that the inclusion complexes had higher antioxidant activities compared to free Hyp in vitro and the H₂O₂–RAW264.7 cell model. Therefore, encapsulation with CDs can not only improve Hyp’s water solubility but can also enhance its biological activity, which provides useful information for the potential application of complexation with Hyp in a clinical context.     

Release of Cinnamaldehyde and Thymol from PLA/Tilapia Fish Gelatin-Sodium Alginate Bilayer Films to Liquid and Solid Food Simulants,and Japanese Sea Bass: A Comparative Study

This study aimed to develop an active biodegradable bilayer film and to investigate the release behaviors of active compounds into different food matrices. Cinnamaldehyde (CI) or thymol (Ty) was encapsulated in β-cyclodextrin (β-CD) to prepare the active β-CD inclusion complex (β-CD-CI/β-CD-Ty). The tilapia fish gelatin-sodium alginate composite (FGSA) containing β-CD-CI or β-CD-Ty was coated on the surface of PLA film to obtain the active bilayer film. Different food simulants including liquid food simulants (water, 3% acetic acid, 10% ethanol, and 95% ethanol), solid dry food simulant (modified polyphenylene oxide (Tenax TA)), and the real food (Japanese sea bass) were selected to investigate the release behaviors of bilayer films into different food matrixes. The results showed that the prepared β-CD inclusion complexes distributed evenly in the cross-linking structure of FGSA and improved the thickness and water contact angle of the bilayer films. Active compounds possessed the lowest release rates in Tenax TA, compared to the release to liquid simulants and sea bass. CI and Ty sustained the release to the sea bass matrix with a similar behavior to the release to 95% ethanol. The bilayer film containing β-CD-Ty exhibited stronger active antibacterial and antioxidant activities, probably due to the higher release efficiency of Ty in test mediums.     

Manufacturing and Assessing the New Orally Disintegrating Tablets,Containing Nimodipine-hydroxypropyl-β-cyclodextrin and Nimodipine-methyl-β-cyclodextrin Inclusion Complexes

The aim of the present study was to manufacture new orally disintegrating tablets containing nimodipine–hydroxypropyl-β-cyclodextrin and nimodipine–methyl-β-cyclodextrin inclusion complexes. For obtaining a better quality of the manufactured tablets, three methods of the preparation of inclusion complexes, in a 1:1 molar ratio, were used comparatively; namely, a solid-state kneading method and two liquid state coprecipitation and lyophilization techniques. The physical and chemical properties of the obtained inclusion complexes, as well as their physical mixtures, were investigated using Fourier transformed infrared spectroscopy, scanning electron microscopy, X-ray diffraction analyses, and differential scanning calorimetry. The results showed that the lyophilization method can be successfully used for a better complexation. Finally, the formulation and precompression studies for tablets for oral dispersion, containing Nim–HP-β-CD and Nim–Me-β-CD inclusion complexes, were successfully assessed.     

Encapsulation of α-Pinene in Delivery Systems Based on Liposomes and Cyclodextrins

The essential oil component α-pinene has multiple biological activities. However, its application is limited owing to its volatility, low aqueous solubility, and chemical instability. For the aim of improving its physicochemical properties, α-pinene was encapsulated in conventional liposomes (CLs) and drug-in-cyclodextrin-in-liposomes (DCLs). Hydroxypropyl-β-cyclodextrin/α-pinene (HP-β-CD/α-pinene) inclusion complexes were prepared in aqueous solution, and the optimal solubilization of α-pinene occurred at HP-β-CD:α-pinene molar ratio of 7.5:1. The ethanol-injection method was applied to produce different formulations using saturated (Phospholipon 90H) or unsaturated (Lipoid S100) phospholipids in combination with cholesterol. The size, the phospholipid and cholesterol incorporation rates, the encapsulation efficiency (EE), and the loading rate (LR) of α-pinene were determined, and the storage stability of liposomes was assessed. The results showed that α-pinene was efficiently entrapped in CLs and DCLs with high EE values. Moreover, Lipoid S100 CLs displayed the highest LR (22.9 ± 2.2%) of α-pinene compared to the other formulations. Both carrier systems HP-β-CD/α-pinene inclusion complex and Lipoid S100 CLs presented a gradual release of α-pinene. Furthermore, the DPPH radical scavenging activity of α-pinene was maintained upon encapsulation in Lipoid S100 CLs. Finally, it was found that all formulations were stable after three months of storage at 4 °C.     

Novel β-Cyclodextrin and Catnip Essential Oil Inclusion Complex and Its Tick Repellent Properties

Cyclodextrin inclusion complexes have been successfully used to encapsulate essential oils, improving their physicochemical properties and pharmacological effects. Besides being well-known for its effects on cats and other felines, catnip (Nepeta cataria) essential oil demonstrates repellency against blood-feeding pests such as mosquitoes. This study evaluates the tick repellency of catnip oil alone and encapsulated in β-cyclodextrin, prepared using the co-precipitation method at a 1:1 molar ratio. The physicochemical properties of this inclusion complex were characterized using GC-FID for encapsulation efficiency and yield and SPME/GC-MS for volatile emission. Qualitative assessment of complex formation was done by UV-Vis, FT-IR, ¹H NMR, and SEM analyses. Catnip oil at 5% (v/v) demonstrated significant tick repellency over time, being comparable to DEET as used in commercial products. The prepared [catnip: β-CD] inclusion complex exerted significant tick repellency at lower concentration of the essential oil (equivalent of 1% v/v). The inclusion complex showed that the release of the active ingredient was consistent after 6 h, which could improve the effective repellent duration. These results demonstrated the effective tick repellent activity of catnip essential oil and the successful synthesis of the inclusion complex, suggesting that β-CDs are promising carriers to improve catnip oil properties and to expand its use in repellent formulations for tick management.     

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.     

Picking Out Logic Operations in a Naphthalene β-Diketone Derivative by Using Molecular Encapsulation,Controlled Protonation,and DNA Binding

On–off switching and molecular logic in fluorescent molecules are associated with what chemical inputs can do to the structure and dynamics of these molecules. Herein, we report the structure of a naphthalene derivative, the fashion of its binding to β-cyclodextrin and DNA, and the operation of logic possible using protons, cyclodextrin, and DNA as chemical inputs. The compound crystallizes out in a keto-amine form, with intramolecular N−H⋅⋅⋅O bonding. It shows stepwise formation of 1:1 and 1:2 inclusion complexes with β-cyclodextrin. The aminopentenone substituents are encapsulated by β-cyclodextrin, leaving out the naphthalene rings free. The binding constant of the β-cyclodextrin complex is 512 m⁻¹. The pK_a value of the guest molecule is not greatly affected by the complexation. Dual input logic operations, based on various chemical inputs, lead to the possibility of several molecular logic gates, namely NOR, XOR, NAND, and Buffer. Such chemical inputs on the naphthalene derivative are examples of how variable signal outputs based on binding can be derived, which, in turn, are dependent on the size and shape of the molecule.     

Comprehensive Characterisation of the Ketoprofen-β-Cyclodextrin Inclusion Complex Using X-ray Techniques and NMR Spectroscopy

Racemic ketoprofen (KP) and β-cyclodextrin (β-CD) powder samples from co-precipitation (1), evaporation (2), and heating-under-reflux (3) were analysed using X-ray techniques and nuclear magnetic resonance (NMR) spectroscopy. On the basis of NMR studies carried out in an aqueous solution, it was found that in the samples obtained by methods 1 and 2, there were large excesses of β-CD in relation to KP, 10 and 75 times, respectively, while the sample obtained by method 3 contained equimolar amounts of β-CD and KP. NMR results indicated that KP/β-CD inclusion complexes were formed and the estimated binding constants were approximately 2400 M⁻¹, showing that KP is quite strongly associated with β-CD. On the other hand, the X-ray single-crystal technique in the solid state revealed that the (S)-KP/β-CD inclusion complex with a stoichiometry of 2:2 was obtained as a result of heating-under-reflux, for which the crystal and molecular structure were examined. Among the methods used for the preparation of the KP/β-CD complex, only method 3 is suitable.     

Cyclodextrin Complexed Lipid Nanoparticles of Irbesartan for Oral Applications: Design,Development, and In Vitro Characterization

Irbesartan (IR) is an angiotensin II receptor antagonist drug with antihypertensive activity. IR bioavailability is limited due to poor solubility and first-pass metabolism. The current investigation aimed to design, develop, and characterize the cyclodextrin(s) (CD) complexed IR (IR-CD) loaded solid lipid nanoparticles (IR-CD-SLNs) for enhanced solubility, sustained release behavior, and subsequently improved bioavailability through oral administration. Based on phase solubility studies, solid complexes were prepared by the coacervation followed by lyophilization method and characterized for drug content, inclusion efficiency, solubility, and in vitro dissolution. IR-CD inclusion complexes demonstrated enhancement of solubility and dissolution rate of IR. However, the dissolution efficiency was significantly increased with hydroxypropyl-βCD (HP-βCD) inclusion complex than beta-CD (βCD). SLNs were obtained by hot homogenization coupled with the ultrasonication method with IR/HP-βCD inclusion complex loaded into Dynasan 112 and glycerol monostearate (GMS). SLNs were evaluated for physicochemical characteristics, in vitro release, differential scanning calorimetry (DSC), powder X-ray diffractometry (PXRD), and physical stability at room temperature for two months. The optimized SLNs formulation showed particle size, polydispersity index, zeta potential, assay, and entrapment efficiency of 257.6 ± 5.1 nm, 0.21 ± 0.03, −30.5 ± 4.1 mV, 99.8 ± 2.5, and 93.7 ± 2.5%, respectively. IR-CD-SLN and IR-SLN dispersions showed sustained release of IR compared to the IR-CD inclusion complexes. DSC results complimented PXRD results by the absence of IR endothermic peak. Optimized IR-CD complex, IR-SLN, and IR-CD-SLN formulations were stable for two months at room temperature. Thus, the current IR oral formulation may exhibit improved oral bioavailability and prolonged antihypertensive activity, which may improve therapeutic outcomes in the treatment of hypertension and heart failure.     

Redox-responsive supramolecular polymeric networks having double-threaded inclusion complexes

Stimuli-responsive hydrogels have attracted attention as soft actuators that act similarly to muscles. In this work, hydrogel actuators controlled by host–guest interactions have been developed. The introduction of a 1:1 inclusion complex into a hydrogel is a popular design for achieving a change in cross-linking density. To realize faster and larger deformation properties, the introduction of a 1:2 inclusion complex is effective because the alteration in cross-linking density in a hydrogel with 1:2 complexes is larger than that in a hydrogel with 1:1 complexes. A redox-responsive hydrogel actuator cross-linked with 1:2 inclusion complexes is designed, where γ-cyclodextrin (γCD) and viologens modified with an alkyl chain derivative (VC11) were employed as the host and guest units, respectively. γCD includes two VC11 molecules in its cavity. The obtained γCD–VC11 hydrogel cross-linked with the 1:2 complex showed faster and larger deformation behaviour than the αCD–VC11 and the βCD–VC11 hydrogels cross-linked with a 1:1 complex. The deformation ratio and response speed of the γCD–VC11 hydrogel, which forms a supramolecular cross-linking structure by stimuli, are 3 and 11 times larger, respectively, than those of our previous hydrogel consisting of a βCD/ferrocene 1:1 inclusion complex.

A hydrogel actuator with a 1:2 host–guest complex controlled by redox stimuli has been developed to realize faster and larger deformation.     

Encapsulation of Risperidone by Methylated β-Cyclodextrins: Physicochemical and Molecular Modeling Studies

Risperidone (RSP) is an atypical antipsychotic drug which acts as a potent antagonist of serotonin-2 (5TH2) and dopamine-2 (D2) receptors in the brain; it is used to treat schizophrenia, behavioral and psychological symptoms of dementia and irritability associated with autism. It is a poorly water soluble benzoxazole derivative with high lipophilicity. Supramolecular adducts between drug substance and two methylated β-cyclodextrins, namely heptakis(2,6-di-O-methyl)-β-cyclodextrin (DM-β-CD) and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TM-β-CD) were obtained in order to enhance RSP solubility and improve its biopharmaceutical profile. The inclusion complexes were evaluated by means of thermoanalytical methods (TG—thermogravimetry/DTG—derivative thermogravimetry/HF—heat flow), powder X-ray diffractometry (PXRD), universal-attenuated total reflectance Fourier transform infrared (UATR-FTIR), UV spectroscopy and saturation solubility studies. Job’s method was employed for the determination of the stoichiometry of the inclusion complexes, which was found to be 2:1 for both guest–host systems. Molecular modeling studies were carried out for an in-depth characterization of the interaction between drug substance and cyclodextrins (CDs). The physicochemical properties of the supramolecular systems differ from those of RSP, demonstrating the inclusion complex formation between drug and CDs. The RSP solubility was enhanced as a result of drug encapsulation in the CDs cavity, the higher increase being obtained with DM-β-CD as host; the guest–host system RSP/DM-β-CD can thus be a starting point for further research in developing new formulations containing RSP, with enhanced bioavailability.     

An Optimization Procedure for Preparing Aqueous CAR/HP-CD Aggregate Dispersions

β-Carotene is a very important molecule for human health. It finds a large application in the food industry, especially for the development of functional foods and dietary supplements. However, β-carotene is an unstable compound and is sensitive to light, temperature, and oxygen. To overcome those limitations, various delivery systems were developed. The inclusion of β-carotene by cyclodextrin aggregates is attractive due to non-toxicity, low hygroscopicity, stability, and the inexpensiveness of cyclodextrins. In this study, β-carotene/2-hydroxypropyl-β-cyclodextrin aggregates were prepared based on the procedure of the addition of β-carotene in an organic solvent to the hot water dispersion of 2-hydroxypropyl-β-cyclodextrin and the following instant evaporation of the organic solvent. The best conditions for the aggregate preparation were found to be as follows: 25% concentration of 2-hydroxypropyl-β-cyclodextrin in water, 65 °C temperature, and acetone for β-carotene dissolution. The efficiency of entrapping was equal to 88%. The procedure is attractive due to the short time of the aggregate preparation.     

Improvement in Solubility–Permeability Interplay of Psoralens from Brosimum gaudichaudii Plant Extract upon Complexation with Hydroxypropyl-β-cyclodextrin

Psoralen (PSO) and 5-methoxypsoralen (5-MOP) are widely used drugs in oral photochemotherapy against vitiligo and major bioactive components of root bark extract of Brosimum gaudichaudii Trécul (EBGT), previously standardized by LC-MS. However, the exceptionally low water solubility of these psoralens can cause incomplete and variable bioavailability limiting their applications and patient adherence to treatment. Therefore, the purpose of this work was to investigate the effects of 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) inclusion complex on the solubility and jejunal permeability of PSO and 5-MOP from EBGT. Characterization of inclusion complexes were evaluated by current methods in nuclear magnetic resonance studies on aqueous solution, Fourier transform infrared spectroscopy, thermal analysis, and scanning electron microscopy in solid state. Ex vivo rat jejunal permeability was also investigated and compared for both pure psoralens and plant extract formulation over a wide HP-β-CD concentration range (2.5 to 70 mM). Phase solubility studies of the PSO- and 5-MOP-HP-β-CD inclusion complex showed 1:1 inclusion complex formation with small stability constants (K_c < 500 M⁻¹). PSO and 5-MOP permeability rate decreased after adding HP-β-CD by 6- and 4-fold for pure standards and EBGT markers, respectively. Nevertheless, the complexation with HP-β-CD significantly improved solubility of PSO (until 10-fold) and 5-MOP (until 31-fold). As a result, the permeability drop could be overcome by solubility augmentation, implying that the HP-β-CD inclusion complexes with PSO, 5-MOP, or EBGT can be a valuable tool for designing and developing novel oral drug product formulation containing these psoralens for the treatment of vitiligo.     

β-Cyclodextrin Inclusion Complexes with Catechol-Containing Antioxidants Protocatechuic Aldehyde and Protocatechuic Acid—An Atomistic Perspective on Structural and Thermodynamic Stabilities

Protocatechuic aldehyde (PCAL) and protocatechuic acid (PCAC) are catechol derivatives and have broad therapeutic effects associated with their antiradical activity. Their pharmacological and physicochemical properties have been improved via the cyclodextrin (CD) encapsulation. Because the characteristics of β-CD inclusion complexes with PCAL (1) and PCAC (2) are still equivocal, we get to the bottom of the inclusion complexation by an integrated study of single-crystal X-ray diffraction and DFT full-geometry optimization. X-ray analysis unveiled that PCAL and PCAC are nearly totally shielded in the β-CD wall. Their aromatic rings are vertically aligned in the β-CD cavity such that the functional groups on the opposite side of the ring (3,4-di(OH) and 1-CHO/1-COOH groups) are placed nearby the O6–H and O2–H/O3–H rims, respectively. The preferred inclusion modes in 1 and 2 help to establish crystal contacts of OH⋅⋅⋅O H-bonds with the adjacent β-CD OH groups and water molecules. By contrast, the DFT-optimized structures of both complexes in the gas phase are thermodynamically stable via the four newly formed host–guest OH⋯O H-bonds. The intermolecular OH⋅⋅⋅O H-bonds between PCAL/PCAC 3,4-di(OH) and β-CD O6–H groups, and the shielding of OH groups in the β-CD wall help to stabilize these antioxidants in the β-CD cavity, as observed in our earlier studies. Moreover, PCAL and PCAC in distinct lattice environments are compared for insights into their structural flexibility.     

Molecular Dynamic Simulation Analysis on the Inclusion Complexation of Plumbagin with β-Cyclodextrin Derivatives in Aqueous Solution

Stable encapsulation of medically active compounds can lead to longer storage life and facilitate the slow-release mechanism. In this work, the dynamic and molecular interactions between plumbagin molecule with β-cyclodextrin (BCD) and its two derivatives, which are dimethyl-β-cyclodextrin (MBCD), and 2-O-monohydroxypropyl-β-cyclodextrin (HPBCD) were investigated. Molecular dynamics simulations (MD) with GLYCAM-06 and AMBER force fields were used to simulate the inclusion complex systems under storage temperature (4 °C) in an aqueous solution. The simulation results suggested that HPBCD is the best encapsulation agent to produce stable host–guest binding with plumbagin. Moreover, the observation of the plumbagin dynamic inside the binding cavity revealed that it tends to orient the methyl group toward the wider rim of HPBCD. Therefore, HPBCD is a decent candidate for the preservation of plumbagin with a promising longer storage life and presents the opportunity to facilitate the slow-release mechanism.     

Adjusting the Structure of β-Cyclodextrin to Improve Complexation of Anthraquinone-Derived Drugs

β-Cyclodextrin (CD) derivatives containing an aromatic triazole ring were studied as potential carriers of the following drugs containing an anthraquinone moiety: anthraquinone-2-sulfonic acid (AQ2S); anthraquinone-2-carboxylic acid (AQ2CA); and a common anthracycline, daunorubicin (DNR). UV-Vis and voltammetry measurements were carried out to determine the solubilities and association constants of the complexes formed, and the results revealed the unique properties of the chosen CDs as effective pH-dependent drug complexing agents. The association constants of the drug complexes with the CDs containing a triazole and lipoic acid (βCDLip) or galactosamine (βCDGAL), were significantly larger than that of the native βCD. The AQ2CA and AQ2S drugs were poorly soluble, and their solubilities increased as a result of complex formation with βCDLip and βCDGAL ligands. AQ2CA and AQ2S are negatively charged at pH 7.4. Therefore, they were less prone to form an inclusion complex with the hydrophobic CD cavity than at pH 3 (characteristic of gastric juices) when protonated. The βCDTriazole and βCDGAL ligands were found to form weaker inclusion complexes with the positively charged drug DNR at an acidic pH (pH 5.5) than in a neutral medium (pH 7.4) in which the drug dissociates to its neutral, uncharged form. This pH dependence is favorable for antitumor applications.     

Thermal Degradation of Linalool-Chemotype Cinnamomum osmophloeum Leaf Essential Oil and Its Stabilization by Microencapsulation with β-Cyclodextrin

The thermal degradation of linalool-chemotype Cinnamomum osmophloeum leaf essential oil and the stability effect of microencapsulation of leaf essential oil with β-cyclodextrin were studied. After thermal degradation of linalool-chemotype leaf essential oil, degraded compounds including β-myrcene, cis-ocimene and trans-ocimene, were formed through the dehydroxylation of linalool; and ene cyclization also occurs to linalool and its dehydroxylated products to form the compounds such as limonene, terpinolene and α-terpinene. The optimal microencapsulation conditions of leaf essential oil microcapsules were at a leaf essential oil to the β-cyclodextrin ratio of 15:85 and with a solvent ratio (ethanol to water) of 1:5. The maximum yield of leaf essential oil microencapsulated with β-cyclodextrin was 96.5%. According to results from the accelerated dry-heat aging test, β-cyclodextrin was fairly stable at 105 °C, and microencapsulation with β-cyclodextrin can efficiently slow down the emission of linalool-chemotype C. osmophloeum leaf essential oil.     

Insulin Complexation with Cyclodextrins—A Molecular Modeling Approach

Around 5% of the population of the world is affected with the disease called diabetes mellitus. The main medication of the diabetes is the insulin; the active form is the insulin monomer, which is an instable molecule, because the long storage time, or the high temperature, can cause the monomer insulin to adapt an alternative fold, rich in β-sheets, which is pharmaceutically inactive. The aim of this study is to form different insulin complexes with all the cyclodextrin used for pharmaceutical excipients (native cyclodextrin, methyl, hydroxyethyl, hydroxypropyl and sulfobutylether substituted β-cyclodextrin), in silico condition, with the AutoDock molecular modeling program, to determine the best type of cyclodextrin or cyclodextrin derivate to form a complex with an insulin monomer, to predict the molar ratio, the conformation of the complex, and the intermolecular hydrogen bonds formed between the cyclodextrin and the insulin. From the results calculated by the AutoDock program it can be predicted that insulin can make a stable complex with 5–7 molecules of hydroxypropyl-β-cyclodextrin or sulfobutylether-β-cyclodextrin, and by forming a complex potentially can prevent or delay the amyloid fibrillation of the insulin and increase the stability of the molecule.     

One-Step Extraction of Olive Phenols from Aqueous Solution Using β-Cyclodextrin in the Solid State,a Simple Eco-Friendly Method Providing Photochemical Stability to the Extracts

The extraction of phenolic compounds from olive mill wastes is important, not only to avoid environmental damages, but also because of the intrinsic value of those biophenols, well-known for their high antioxidant potential and health benefits. This study focuses on tyrosol (Tyr) and hydroxytyrosol (HT), two of the main phenolic compounds found in olive mill wastes. A new, simple, and eco-friendly extraction process for the removal of phenolic compounds from aqueous solutions using native β-cyclodextrin (β-CD) in the solid state has been developed. Several β-CD/biophenol molar ratios and biophenol concentrations were investigated, in order to maintain β-CD mostly in the solid state while optimizing the extraction yield and the loading capacity of the sorbent. The extraction efficiencies of Tyr and HT were up to 61%, with a total solid recovery higher than 90% using an initial concentration of 100 mM biophenol and 10 molar equivalents of β-CD. The photochemical stability of the complexes thus obtained was estimated from ∆E*ab curve vs. illumination time. The results obtained showed that the phenols encapsulated into solid β-CD are protected against photodegradation. The powder obtained could be directly developed as a safe-grade food supplement. This simple eco-friendly process could be used for extracting valuable biophenols from olive mill wastewater.