Ternary cyclodextrin polyurethanes containing phosphate groups: Synthesis and complexation of ciprofloxacin

Cyclodextrin Inclusion Complexes with Antibiotics and Antibacterial Agents as Drug-Delivery Systems—A Pharmaceutical Perspective

Cyclodextrins (CDs) are a family of cyclic oligosaccharides, consisting of a macrocyclic ring of glucose subunits linked by α-1,4 glycosidic bonds. The shape of CD molecules is similar to a truncated cone with a hydrophobic inner cavity and a hydrophilic surface, which allows the formation of inclusion complexes with various molecules. This review article summarises over 200 reports published by the end of 2021 that discuss the complexation of CDs with antibiotics and antibacterial agents, including beta-lactams, tetracyclines, quinolones, macrolides, aminoglycosides, glycopeptides, polypeptides, nitroimidazoles, and oxazolidinones. The review focuses on drug-delivery applications such as improving solubility, modifying the drug-release profile, slowing down the degradation of the drug, improving biological membrane permeability, and enhancing antimicrobial activity. In addition to simple drug/CD combinations, ternary systems with additional auxiliary substances have been described, as well as more sophisticated drug-delivery systems including nanosponges, nanofibres, nanoparticles, microparticles, liposomes, hydrogels, and macromolecules. Depending on the desired properties of the drug product, an accelerated or prolonged dissolution profile can be achieved when combining CD with antibiotics or antimicrobial agents.

In Silico Study, Physicochemical, and In Vitro Lipase Inhibitory Activity of α,β-Amyrenone Inclusion Complexes with Cyclodextrins

α,β-amyrenone (ABAME) is a triterpene derivative with many biological activities; however, its potential pharmacological use is hindered by its low solubility in water. In this context, the present work aimed to develop inclusion complexes (ICs) of ABAME with γ- and β-cyclodextrins (CD), which were systematically characterized through molecular modeling studies as well as FTIR, XRD, DSC, TGA, and SEM analyses. In vitro analyses of lipase activity were performed to evaluate possible anti-obesity properties. Molecular modeling studies indicated that the CD:ABAME ICs prepared at a 2:1 molar ratio would be more stable to the complexation process than those prepared at a 1:1 molar ratio. The physicochemical characterization showed strong evidence that corroborates with the in silico results, and the formation of ICs with CD was capable of inducing changes in ABAME physicochemical properties. ICs was shown to be a stronger inhibitor of lipase activity than Orlistat and to potentiate the inhibitory effects of ABAME on porcine pancreatic enzymes. In conclusion, a new pharmaceutical preparation with potentially improved physicochemical characteristics and inhibitory activity toward lipases was developed in this study, which could prove to be a promising ingredient for future formulations.

Supramolecular polyelectrolyte complexes based on cyclodextrin-grafted chitosan and carrageenan for controlled drug release

In the present study, supramolecular polyelectrolyte complexes (SPEC) based on a cyclodextrin-grafted chitosan derivative and carrageenan were prepared and evaluated for controlled drug release. Samples were characterized by FTIR, SEM, and ζ-potential measurements, which confirmed the formation of the polymeric complex. The phenolphthalein test confirmed the presence and availability of inclusion sites from the attached βCD. Silver sulfadiazine was used as the model drug and the association with the SPEC was studied by FTIR and computational molecular modeling, using a semi-empirical method. DRS and TEM analyses have shown that Ag⁺ ions from the drug were reduced to form metallic silver nanostructures. In vitro tests have shown a clear bacterial activity toward Gram-positive bacteria Staphylococcus aureus and Enterococcus durans/hirae and Gram-negative bacteria Klebsiella pneumoniae and Escherichia coli. Finally, this work shows that βCD-chitosan/carrageenan supramolecular polyelectrolyte complexes hold an expressive potential to be applied as a polymer-based system for controlled drug release.

Complex systems that incorporate cyclodextrins to get materials for some specific applications

Cyclodextrins (CDs) are a family of biodegradable cyclic hydrocarbons composed of α-(1,4) linked glucopyranose subunits, the more common containing 6, 7 or 8 glucose units are named α, β and γ-cyclodextrins respectively. Since the discovery of CDs, they have attracted interest among scientists and the first studies were about the properties of the native compounds and in particular their use as catalysts of organic reactions. Characteristics features of different types of cyclodextrins stimulated investigation in different areas of research, due to its non-toxic and non-inmunogenic properties and also to the development of an improved industrial production. In this way, many materials with important properties have been developed. This mini-review will focus on chemical systems that use cyclodextrins, whatever linked covalently or mediated by the non covalent interactions, to build complex systems developed mainly during the last five years.

Preparation and characterization of porous hydroxyapatite/β-cyclodextrin-based polyurethane composite scaffolds for bone tissue engineering

In this study, novel porous scaffolds containing hydroxyapatite and β-cyclodextrin-based polyurethane were first successfully fabricated by polymerizing β-cyclodextrin with hexamethylene diisocyanate and hydroxyapatite in situ for bone tissue engineering. The physicochemical and mechanical properties as well as cytocompatibility of porous scaffolds were investigated. The results showed that polyurethane reinforced with hydroxyapatite composites had cancellous bone-like porous structure. The mechanical strength of the scaffolds increased with increasing the hydroxyapatite content in scaffolds. Synthesized scaffolds (PU1, PUHA1, PU2, and PUHA2) presented compressive strength values of 0.87 ± 0.24 MPa, 1.81 ± 0.10 MPa, 6.16 ± 0.89 MPa, and 12.95 ± 2.05 MPa, respectively. The pore size and porosity of these scaffolds were suitable for bone regeneration. Cytocompatibility of composite scaffolds was proven via favorable interactions with MC3T3-E1 cells. The addition of hydroxyapatite into CD-based polyurethane scaffolds improved cell attachment, well-spread morphology, and higher proliferation. The hydroxyapatite-polyurethane scaffolds have the potential to be applied in bone repair and regeneration.

Cyclodextrin based nanosponge of norfloxacin: Intestinal permeation enhancement and improved antibacterial activity

Nanosponges are a novel class of hyperbranched cyclodextrin-based nanostructures that exhibits remarkable potential as a drug host system for the improvement in biopharmaceutical properties. This work aims the development of cyclodextrin-based nanosponge of norfloxacin to improve its physicochemical characteristics. β-cyclodextrin was used as base and diphenyl carbonate as crosslinker agent at different proportions to produce nanosponges that were evaluated by in vitro and in vivo techniques. The proportion cyclodextrin:crosslinker 1:2 M/M was chosen due to its higher encapsulation efficiency (80%), revealing an average diameter size of 40 nm with zeta potential of -19 mV. Norfloxacin-loaded nanosponges exhibited higher passage of norfloxacin in comparison to norfloxacin drug alone by Ussing chamber method. The nanosponge formulation also revealed a mucoadhesive property that could increase norfloxacin absorption thus improving its antibiotic activity in an in vivo sepsis model. Therefore, nanosponges may be suitable carrier of norfloxacin to maximize and facilitate oral absorption.