Probing Host-Guest inclusion complexes of Ambroxol Hydrochloride with α- & β-Cyclodextrins by physicochemical contrivance subsequently optimized by molecular modeling simulations

Investigation of Host-Guest Inclusion Complex of Mephenesin with α-Cyclodextrin for Innovative Application in Biological System

The goal of this study was to use coevaporation to look into how polyether compounds like mephenesin (MEP) can be encapsulated into the host molecule α-cyclodextrin's nanohydrophobic cage. Fourier transform infrared spectroscopy (FT-IR) investigations, powder X-ray diffraction (PXRD), and 1H NMR were among the spectroscopic techniques used to describe the inclusion complex. Additionally, Job's plot has been utilized to illustrate how MEP is encapsulated with α-cyclodextrin (α-CD) at a 1:1 molar ratio. The thermal stability of MEP increased after encapsulation according to thermogravimetric analysis (TGA) and differential thermal analysis (DTA) experiments. Mephenesin fits into the cavity of α-cyclodextrin in a 1:1 ratio, as observed by molecular docking for the inclusion complex to find the most appropriate orientation. This observation is further supported by the Job plot. Furthermore, a comparison was carried out based on a cell viability study between the medication and its inclusion complex.

Inclusion complexes of β-cyclodextrin with isomeric ester aroma compounds: Preparation, characterization, mechanism study, and controlled release

Cyclodextrins (CDs) have been discovered to provide an efficient solution to the limited application of ester aroma molecules used in food, tobacco, and medication due to their strong smell and unstable storage. This work combined molecular modeling and experimental to analyze the conformation and controlled release of isomeric ester aroma compounds/β-CD inclusion complexes (ICs). The investigation revealed that ester aroma compounds could be effectively encapsulated within the β-CD cavity, forming ICs with low binding affinity. Furthermore, the key driving forces in ICs were identified as hydrogen bonds and van der Waals interactions through theoretical simulation. Results from the Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR) and Isothermal titration calorimetry (ITC) experiments confirmed the intermolecular interaction predicted by the molecular model. Notably, the release rate of aroma compounds from L-menthyl acetate/β-CD (LMA/β-CD) IC exceeded that of terpinyl acetate/β-CD (TA/β-CD) IC. This difference is attributed to the length of the chain of aroma molecules and the variation in the position of functional groups, influencing the stable formation of ICs with β-CD. These findings hold potential implications for refining the application of ICs across diverse industries.

Development and characterization of a spray-dried inhalable ternary combination for the treatment of Pseudomonas aeruginosa biofilm infection in cystic fibrosis

Cystic fibrosis (CF) is an inherited lung disease characterised by the accumulation of thick layers of dried mucus in the lungs which serve as a nidus for chronic infection. Pseudomonas aeruginosa is the predominant cause of chronic lung infection in cystic fibrosis. The dense mucus coupled with biofilm formation hinder antibiotic penetration and prevent them from reaching their target. Mucoactive agents are recommended in the treatment of CF in combination with antibiotics. In spite of the extensive research in developing novel drug combinations for the treatment of lung infection in CF, to our knowledge, there is no study that combines antibiotic, antibiofilm and mucoactive agent in a single inhaled dry powder formulation. In the present study, we investigate the possibility of adding a mucoactive agent to our previously developed ciprofloxacinquercetin (antibiotic-antibiofilm) dry powder for inhalation. Three mucoactive agents, namely mannitol (MAN), N-acetyl-L-cysteine (NAC) and ambroxol hydrochloride (AMB), were investigated for this purpose. The ternary combinations were prepared via spray drying without the addition of excipients. All ternary combinations conserved or improved the antibacterial and biofilm inhibition activities of ciprofloxacin against P. aeruginosa (ATCC 10145). The addition of AMB resulted in an amorphous ternary combination (SD-CQA) with superior physical stability as indicated by DSC and nonambient XRPD. Furthermore, SD-CQA displayed better in vitro aerosolization performance (ED ∼ 71 %; FPF ∼ 49 %) compared to formulations containing MAN and NAC (ED ∼ 64 % and 44 %; FPF ∼ 44 % and 29 %, respectively). In conclusion, a ternary drug combination powder with suitable aerosolization, physical stability and antibacterial/antibiofilm properties was prepared by a single spray drying step.

Cyclodextrin-Based Displacement Strategy of Sterigmatocystin from Serum Albumin as a Novel Approach for Acute Poisoning Detoxification

This study demonstrates that sterigmatocystin (STC) interacts non-covalently with various cyclodextrins (CDs), showing the highest binding affinity for sugammadex (a γ-CD derivative) and γ-CD, and an almost order of magnitude lower affinity for β-CD. This difference in affinity was studied using molecular modelling and fluorescence spectroscopy, which demonstrated a better insertion of STC into larger CDs. In parallel, we showed that STC binds to human serum albumin (HSA) (a blood protein known for its role as a transporter of small molecules) with an almost two order of magnitude lower affinity compared to sugammadex and γ-CD. Competitive fluorescence experiments clearly demonstrated an efficient displacement of STC from the STC-HSA complex by cyclodextrins. These results are a proof-of-concept that CDs can be used to complex STC and related mycotoxins. Similarly, as sugammadex extracts neuromuscular relaxants (e.g., rocuronium and vecuronium) from blood and blocks their bioactivity, it could also be used as first aid upon acute intoxication to encapsulate a larger part of the STC mycotoxin from serum albumin.

Preparation, Characterization and Molecular Dynamics Simulation of Rutin-Cyclodextrin Inclusion Complexes

Rutin is a natural flavonoid that carries out a variety of biological activities, but its application in medicine and food is limited by its water solubility. One of the classical methods used to enhance drug solubility is encapsulation with cyclodextrins. In this paper, the encapsulation of different cyclodextrins with rutin was investigated using a combination of experimental and simulation methods. Three inclusions of rutin/beta-cyclodextrin (β-CD), rutin/2-hydroxypropyl beta-cyclodextrin (HP-β-CD) and rutin/2,6-dimethyl beta-cyclodextrin (DM-β-CD) were prepared by the freeze-drying method, and the inclusions were analyzed using Fourier infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), differential scanning calorimetry (DSC) and ultraviolet-visible spectroscopy (UV) to characterize and demonstrate the formation of the inclusion complexes. Phase solubility studies showed that rutin formed a 1:1 stoichiometric inclusion complex and significantly increased its solubility. β-CD, HP-β-CD, DM-β-CD, rutin and the three inclusion complexes were modeled by using MS2018 and AutoDock 4.0, and molecular dynamics simulations were performed to calculate the solubility parameters, binding energies, mean square displacement (MSD), hydrogen bonding and radial distribution functions (RDF) after the equilibration of the systems. The results of simulation and experiment showed that rutin/DM-β-CD had the best encapsulation effect among the three cyclodextrin inclusion complexes.

Preparation, Characterization, and Bioavailability of Host-Guest Inclusion Complex of Ginsenoside Re with Gamma-Cyclodextrin

This work aimed at improving the water solubility of Ginsenoside (G)-Re by forming an inclusion complex. The solubility parameters of G-Re in alpha (α), beta (β), and gamma (γ) cyclodextrin (CD) were investigated. The phase solubility profiles were all classified as AL-type that indicated the 1:1 stoichiometric relationship with the stability constants Ks which were 22 M⁻¹ (α-CD), 612 M⁻¹ (β-CD), and 14,410 M⁻¹ (γ-CD), respectively. Molecular docking studies confirmed the results of phase solubility with the binding energy of −4.7 (α-CD), −5.10 (β-CD), and −6.70 (γ-CD) kcal/mol, respectively. The inclusion complex (IC) of G-Re was prepared with γ-CD via the water-stirring method followed by freeze-drying. The successful preparation of IC was confirmed by powder X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). In-vivo absorption studies were carried out by LC-MS/MS. Dissolution rate of G-Re was increased 9.27 times after inclusion, and the peak blood concentration was 2.7-fold higher than that of pure G-Re powder. The relative bioavailability calculated from the ratio of Area under the curve AUC₀–_∞ of the inclusion to pure G-Re powder was 171%. This study offers the first report that describes G-Re’s inclusion into γ-CD, and explored the inclusion complex’s mechanism at the molecular level. The results indicated that the solubility could be significantly improved as well as the bioavailability, implying γ-CD was a very suitable inclusion host for complex preparation of G-Re.

Application of Molecular Dynamics Simulations in the Analysis of Cyclodextrin Complexes

Cyclodextrins (CDs) are highly respected for their ability to form inclusion complexes via host-guest noncovalent interactions and, thus, ensofance other molecular properties. Various molecular modeling methods have found their applications in the analysis of those complexes. However, as showed in this review, molecular dynamics (MD) simulations could provide the information unobtainable by any other means. It is therefore not surprising that published works on MD simulations used in this field have rapidly increased since the early 2010s. This review provides an overview of the successful applications of MD simulations in the studies on CD complexes. Information that is crucial for MD simulations, such as application of force fields, the length of the simulation, or solvent treatment method, are thoroughly discussed. Therefore, this work can serve as a guide to properly set up such calculations and analyze their results.

Experimental and molecular docking investigation of the inclusion complexes between 20(S)-protopanaxatriol and four modified β-cyclodextrins

20(S)-Protopanaxatriol (PPT) is a type of ginsenoside isolated from panax notoginseng or ginseng, which is an essential ingredient in functional food, healthcare products and traditional medicine. However, the research and development of PPT are restricted due to its poor solubility. To circumvent the associated problems, a novel bridged-bis [6-(2,2'-(ethylenedioxy) bis (ethylamine))-6-deoxy-β-CD] (H4) was successfully synthesized. The four inclusion complexes of the mono-[6-(1,4-butanediamine)-6-deoxy-β-CD] (H1), mono-[6-(2,2'-(ethylenedioxy) bis (ethylamine)-6-deoxy-β-CD] (H2) and their corresponding bridged bis(β-CD)s (H3, H4) with PPT were prepared and studied by UV, ¹H NMR, 2D ROESY, FT-IR, XRD and SEM technology. The UV-spectrometric titration showed that H1-4 and PPT formed 1:1 inclusion complexes and the binding constants were 297.61, 322.25, 937.88 and 1742 M^-1, respectively. It was further revealed that the size/shape-matching relationship, hydrophobic interactions and hydrogen bond interactions play the crucial role in determining the stability of H1-4/PPT inclusion complexes. The solubility of PPT was evidently enhanced by193, 265, 453 and 593 times after the formation of inclusion complexes with H1-4, respectively. Furthermore, molecular docking was used to verify the inclusion mode of H4/PPT inclusion complex and also to investigate the stability of H4/PPT in water phase. The molecular simulation results agreed well with the experimental results. This research provides an effective way to obtain novel PPT-based functional food and healthcare products.

Exploring the Inclusion Complex of a Drug (Umbelliferone) with α-Cyclodextrin Optimized by Molecular Docking and Increasing Bioavailability with Minimizing the Doses in Human Body

In this study, umbelliferone and α-cyclodextrin host molecules have been mixed up through a coprecipitation method to prepare a supramolecular complex to provide physical insights into the formation and stability of the inclusion complex (IC). The prepared hybrid was characterized by ¹H nuclear magnetic resonance (¹H NMR), Fourier transform infrared (FTIR) spectroscopy, electrospray ionization (ESI) mass spectrometry, DSC, and fluorescence spectroscopic studies. Job's plot provides a stoichiometric ratio of 1:1 and the Benesi-Hildebrand double reciprocal plot gives binding constant values using fluorescence spectroscopic titrations and the ESI mass data support the experimental observations. The results of molecular modeling were systematically analyzed to validate the inclusion complexation. In preliminary computational screening, α-cyclodextrin IC of umbelliferone was found to be quite stable based on the docking score, binding free energies, and dynamic simulations. In addition, the results obtained from ¹H NMR and FTIR spectroscopy studies supported the inclusion complexation phenomenon. The results obtained from computational studies were found to be consistent with the experimental data to ascertain the encapsulation of umbelliferone into α-cyclodextrin.