Effect of external factors on the curcumin/2-hydroxypropyl-β-cyclodextrin: in vitro and in vivo study

Bioactivity and Cell Imaging of Antitumor Fluorescent Agents (Curcumin Derivatives) Coated by Two-Way Embedded Cyclodextrin Strategy

Curcumin has a wide range of pharmacological activities, which can be used to treat tumors, inflammation and other diseases. However, curcumin's poor solubility and low bioavailability limit its application. In this article, the structure of curcumin was modified with boron trifluoride ether to change fluorescent labeling. The compounds were then embedded into the hydrophobic cavity of α-cyclodextrin and hydroxypropyl β-cyclodextrin to form inclusion complexes. The two inclusion complexes have excellent photophysical properties, and the maximum emission wavelength is in the range of 550-565 nm. In addition, the two compounds were applied to the fluorescence imaging of HCT-116 cells and HeLa cells, and the proliferation toxicity of the compounds was detected. Both compounds showed certain inhibitory effects on the proliferation of cancer cells. In short, the fluorescent drug molecule synthesized in this article has great reference value for the development of new dosage forms of curcumin.

Enhancing the water-solubility of curcuminoids-rich extract using a ternary inclusion complex system: Preparation, characterization, and anti-cancer activity

Curcuminoids are known to exert diverse pharmacological effects and used in some pharmaceutical formulations. This study describes the preparation, characterization, and enhancement in the solubility and anticancer activity of a curcuminoids-rich extract (CRE) using a ternary inclusion complex system. CRE containing 88.9% w/w curcuminoids was prepared using a 'green' microwave extraction coupled with fractionation on a column of hydrophobic adsorbent resin. The ternary complex consisting of CRE, hydroxylpropyl-β-cyclodextrin and polyvinylpyrrolidone K30 was prepared using the solvent evaporation method and thoroughly characterized using Fourier-transform infrared spectroscopy, powder X-ray diffractograms, differential scanning calorimetry and scanning electron microscopy. The ternary complex of CRE improved the water-solubility of curcuminoids (up to 70.3 µg/mL) as well as the dissolution rate when compared to those of CRE (0 µg/mL). In addition, the ternary complex exhibited significantly stronger anticancer activity against human lung adenocarcinoma (A-549), human cervical adenocarcinoma (HeLa) and human colon adenocarcinoma (HT-29) cell lines than CRE.

Development of fast-dissolving dosage forms of curcuminoids by electrospinning for potential tumor therapy application

Curcuminoids (CUs) of antitumor and various other potential biological activities have extremely low water solubility therefore special formulation was elaborated. New fast dissolving reconstitution dosage forms of four CUs were prepared as fibrous form of 2-hydroxypropyl-β-cyclodextin (HP-β-CD). In the electrospinning process HP-β-CD could act both as solubilizer and fiber-forming agent. The solubilization efficiency of the CU-HP-β-CD systems was determined with phase-solubility measurements. The electrospun CUs were amorphous and uniformly distributed in the fibers according to XRD analysis and Raman mappings. The fibrous final products had fast (<5 min) and complete dissolution. In typical iv. infusion reconstitution volume (20 mL) fibers containing 40-80 mg of CU could be dissolved, which is similar to the currently proposed dose (<120 mg/m²). The in vitro cytostatic effect data showed that the antitumor activity of the CU-HP-β-CD complexes was similar or better compared to the free APIs.

The soluble curcumin derivative NDS27 inhibits superoxide anion production by neutrophils and acts as substrate and reversible inhibitor of myeloperoxidase

A water-soluble curcumin lysinate incorporated into hydroxypropyl-β-cyclodextrin (NDS27) has been developed and shown anti-inflammatory properties but no comparative study has been made in parallel with its parent molecule, curcumin on polymorphonuclear neutrophils (PMNs) and myeloperoxidase (MPO) involved in inflammation. The effect of NDS27, its excipients (hydroxypropyl-β-cyclodextrin and lysine), curcumin lysinate and curcumin were compared on the release of superoxide anion by PMNs using a chemiluminescence assay and on the enzymatic activity of MPO. It was shown that curcumin and NDS27 exhibit similar inhibition activities on superoxide anion release by stimulated PMNs but also on MPO peroxidase and halogenation activities. The action mechanism of curcumin and NDS27 on the MPO activity was refined by stopped-flow and docking analyses. We demonstrate that both curcumin and NDS27 are reversible inhibitors of MPO by acting as excellent electron donors for redox intermediate Compound I (∼10⁷ M^-1 s^-1) but not for Compound II (∼10³ M^-1 s^-1) in the peroxidase cycle of the enzyme, thereby trapping the enzyme in the Compound II state. Docking calculations show that curcumin is able to enter the enzymatic pocket of MPO and bind to the heme cavity by π-stacking and formation of hydrogen bonds involving substituents from both aromatic rings. Hydroxypropyl-β-cyclodextrin is too bulky to enter MPO channel leading to the binding site suggesting a full release of curcumin from the cyclodextrin thereby allowing its full access to the active site of MPO. In conclusion, the hydroxypropyl-β-cyclodextrin of NDS27 enhances curcumin solubilization without affecting its antioxidant capacity and inhibitory activity on MPO.

Amisulpride-CD-Loaded Liposomes: Optimization and In Vivo Evaluation

Amisulpride (AMS) is an atypical antipsychotic agent used for the treatment of schizophrenia. The effect of different variables, i.e., the type of cyclodextrins (CDs), ratio of drug/CDs, and type of loading on the prepared AMS-CD liposomes (single and double loaded) was studied by applying 2³ full factorial design. Double-loaded liposomes are loaded with AMS-hydroxyl propyl-β-cyclodextrin (HP-β-CD) in the aqueous phase and free drug in the lipophilic bilayer, while single-loaded liposomes are loaded only with AMS-HP-β-CD in the aqueous phase. Entrapment efficiency, particle size, polydespersibility, and zeta potential were selected as dependent variables. Design Expert® software was used to obtain an optimized formulation with high entrapment efficiency (64.55 ± 1.27%), average particle size of 40.1 ± 2.77 nm, polydespersibility of 0.44 ± 0.37, and zeta potential of - 48.8 ± 0.28. Optimized formula was evaluated for in vitro release, surface morphology and stability study was also conducted. AMS-HP-β-CD in double-loaded liposomes exhibited higher drug release than those in the conventional liposomes and in the single-loaded liposomes. The maximum plasma concentration (C_max) of AMS in optimized AMS-HP-β-CD double-loaded liposomal formulation increased by 1.55- and 1.29-fold, as compared to the commercial tablets and conventional liposomes, respectively. However, the relative bioavailability of AMS double-loaded liposomes was 1.94- and 1.28-folds of commercial tablet and conventional liposomes, respectively.

A comparison between conventional liposome and drug-cyclodextrin complex in liposome system

A drug-cyclodextrin complex in liposome system was prepared in order to make a comparison with conventional risperidone-loaded liposome. Thin film hydration, reverse phase evaporation and ethanol injection methods were taken as preparation means to obtain the two types of liposome. Differential thermal analysis (DTA) and transmission electron microscopy (TEM) were used to investigate the thermal characters of inclusion complexes and morphology of liposome, respectively. Particle size, zeta potential and encapsulation efficiency were studied by light scattering analysis and ultrafiltration. In vitro release was carried out in the pH 7.4 phosphate buffer solution and samples were collected at the certain time. As a result, drug-cyclodextrin complex in liposome prepared by various methods displayed lower encapsulation efficiency than conventional liposome. However, size was larger and its stability was better than the latter. The second release phase of novel delivery system was slightly slower after initial burst release at the first phase, while the conventional liposome displayed a more regular trait. Thus, the novel liposome have potential to be developed as co-administration formulation with long-acting injection.

Dual drug-loaded halloysite hybrid-based glycocluster for sustained release of hydrophobic molecules

A dual drug-loaded HNT–CD glycocluster delivery system based on halloysite nanotubes and carbohydrate functionalized cyclodextrin for delivery of natural drugs was developed.

Combination of counterpropagation artificial neural networks and antioxidant activities for comprehensive evaluation of associated-extraction efficiency of various cyclodextrins in the traditional Chinese formula Xue-Zhi-Ning

Xue-Zhi-Ning (XZN) is a widely used traditional Chinese medicine formula to treat hyperlipidemia. Recently, cyclodextrins (CDs) have been extensively used to minimize problems relative to medicine bioavailability, such as low solubility and poor stability. The objective of this study was to determine the associated-extraction efficiency of various CDs in XZN. Three various type CDs were evaluated, including native CDs (α-CD, β-CD), hydrophilic CD derivatives (HP-β-CD and Me-β-CD), and ionic CD derivatives (SBE-β-CD and CM-β-CD). An ultra high-performance liquid chromatography (UHPLC) fingerprint was applied to determine the components in CD extracts and original aqueous extract (OAE). A counterpropagation artificial neural network (CP-ANN) was used to analyze the components in different extracts and compare the selective extraction of various CDs. Extraction efficiencies of the various CDs in terms of extracted components follow the ranking, ionic CD derivatives>hydrophilic CD derivatives>native CDs>OAE. Besides, different types of CDs have their own selective extraction and ionic CD derivatives present the strongest associated-extraction efficiency. Antioxidant potentials of various extracts were evaluated by determining the inhibition of spontaneous, H2O2-induced, CCl4-induced and Fe(2+)/ascorbic acid-induced lipid peroxidation (LPO) and analyzing the scavenging capacity for DPPH and hydroxyl radicals. The order of extraction efficiencies of the various CDs relative to antioxidant activities is as follows: SBE-β-CD>CM-β-CD>HP-β-CD>Me-β-CD>β-CD>α-CD. It can be demonstrated that all of the CDs studied increase the extraction efficiency and that ionic CD derivatives (SBE-β-CD and CM-β-CD) present the highest extraction capability in terms of amount extracted and antioxidant activities of extracts.

Development of a myricetin/hydroxypropyl-β-cyclodextrin inclusion complex: preparation, characterization, and evaluation

Myricetin shows low oral bioavailability (<10%) in rats due to poor aqueous solubility, though it has various pharmacological activities. Complexation with cyclodextrins (CDs) is a potent pharmaceutical method to enhance the bioavailability of poorly soluble compounds. The myricetin/HP-β-CD inclusion complex was prepared and confirmed by DSC, PXRD, and SEM. Here, the inclusion mode is described in detail with regard to structural and energetic aspects using a phase solubility diagram and 1H NMR, NOESY, and FT-IR spectra. The water solubility and dissolution rate of myricetin were greatly enhanced by forming the myricetin/HP-β-CD inclusion complex. Consequently, the oral bioavailability of the myricetin/HP-β-CD inclusion complex in rats was effectively increased 9.4-fold over free myricetin, and its antioxidant activity was also improved. The present study provides useful information for the potential application of complexation with myricetin, a naturally occurring hydrophobic phenolic compound in herbal medicine.