A thermoresponsive hydrophobically modified hydroxypropylmethylcellulose/cyclodextrin injectable hydrogel for the sustained release of drugs.

The objective of this study was to develop a thermoresponsive injectable hydrogel for the sustained release of drugs by taking advantage of host-guest interactions between a hydrophobically modified hydroxypropylmethyl cellulose (HM-HPMC) and cyclodextrin (CD). A thermoresponsive injectable hydrogel was prepared by simply adding CDs to HM-HPMC hydrogel. The HM-HPMC hydrogel was converted into a sol with a low viscosity through host-guest interactions with CDs.

The Use of Enteric Capsules for Releasing a Fragrance over an Extended Period of Time.

A system for releasing a fragrance, citral (CR) over an extended period of time using three types of enteric capsules is reported. The L- and M-type capsules released CR into media with a pH above 6, while the H-type capsule released CR at a pH above 7. The pH of the releasing medium was controlled by sodium borate (SB), i.

Antioxidant activities of chitosans and its derivatives in in vitro and in vivo studies.

This review focuses on the in vitro and in vivo antioxidant activities of various chitosan preparations, including those with different molecular weights and degrees of acetylation and the nanofibers produced from them. In in vitro studies, low molecular weight (LMW) chitosan with high degrees of deacetylation has more potent antioxidant properties than those of high molecular weight (HMW) chitosan. On the other hand, HMW chitosan has higher adsorption properties than those of LMW chitosan.

Glucose Responsive Rheological Change and Drug Release from a Novel Worm-like Micelle Gel Formed in Cetyltrimethylammonium Bromide/Phenylboronic Acid/Water System.

A novel glucose (Glc)-responsive gel formed by worm-like micelles (WLMs) has the potential to provide a self-regulating insulin delivery system. We have prepared a WLM gel system using 75 mM cetyltrimethylammonium bromide, 75 mM phenylboronic acid, and water. At pH 9.

Surface-deacetylated chitin nanofibers reinforced with a sulfobutyl ether β-cyclodextrin gel loaded with prednisolone as potential therapy for inflammatory bowel disease.

Surface-deacetylated chitin nanofibers (SDACNFs) reinforced with a sulfobutyl ether β-cyclodextrin (SBE-β-CD) (NFs-CDs) gel were developed to obtain a controlled release carrier of prednisolone (PD) for the treatment of colitis. PD was released slowly from the gel at both pH 1.2 and 6.

Hydrophobically Modified Polymer/α-Cyclodextrin Thermoresponsive Hydrogels for Use in Ocular Drug Delivery.

We report herein on the preparation of thermoresponsive hydrogels by taking advantage of the interaction of cyclodextrins (CDs) and a hydrophobically modified polymer. A hydrophobically modified hydroxypropyl methylcellulose (HM-HPMC) gel formed thermoresponsive hydrogels when small amounts of α-CD were added to the solution. The HM-HPMC/α-CD showed reversible sol-gel transition in the physiological temperature range that was completely opposite to the temperature dependency shown by the original HM-HPMC.

Biomaterials based on freeze dried surface-deacetylated chitin nanofibers reinforced with sulfobutyl ether β-cyclodextrin gel in wound dressing applications.

A freeze-dried gel composed of surface-deacetylated chitin nanofibers (SDACNFs), reinforced with an anionic cyclodextrin, sulfobutyl ether β-cyclodextrin (SBE-β-CD) was evaluated for treating wounds in a rat model, and the results were compared with a SDACNFs gel without SBE-β-CD. The incorporation of prednisolone (PD), a poorly water-soluble drug, in both types of gels and its release from the gels were also compared. In both cases, wound areas were decreased and their effect was higher than that of commercially available wound dressings.

In Vitro and In Vivo Evaluation of Hydrophilic C60(OH)10/2-Hydroxypropyl-β-cyclodextrin Nanoparticles as an Antioxidant.

The objective of this study was to assess the antioxidant ability of C60(OH)10/2-hydroxypropyl-β-cyclodextrin (HP-β-CD) nanoparticles, by comparing their scavenging ability for reactive nitrogen species, their cytoprotective effects under conditions of oxidative stress, and their therapeutic effects against diseases that are induced by oxidative stress. The C60(OH)10/HP-β-CD nanoparticles had a higher scavenging activity against nitric acid and peroxynitrite (ONOO(-)) than the other antioxidants such as ascorbic acid, trolox, and edaravone. The cytoprotective effect of C60(OH)10/HP-β-CD nanoparticles was examined on HeLa and HepG2 cells by monitoring the percentage of cell death induced by H2O2.

Ternary inclusion complex formation and stabilization of limaprost, a prostaglandin E1 derivative, in the presence of α- and β-cyclodextrins in the solid state.

Limaprost/α-cyclodextrin (CD)/β-CD ternary inclusion complex was prepared by freeze-drying a solution containing all three components. Under humid conditions, limaprost was more stable in the ternary α-/β-CD inclusion complex than in the binary α- or β-CD complex. Specifically, during storage at 30°C/75% relative humidity (R.

The formation of an inclusion complex between a metabolite of ginsenoside, compound K and γ-cyclodextrin and its dissolution characteristics.

Objectives: 20S-protopanaxadiol 20-O-β-D-glucopyranoside (compound K), a metabolite of ginsenoside, is only sparingly soluble in water. The aim of this study was to improve the low solubility, slow dissolution rate and low oral bioavailability of compound K by forming an inclusion complex with γ-cyclodextrin (γ-CyD), and to compare the results with those of β-CyD complex.

Methods: The interactions of compound K with β and γ-CyDs were studied by the solubility method and proton nuclear magnetic resonance spectroscopy.

Antioxidant and renoprotective activity of 2-hydroxypropyl-β-cyclodextrin in nephrectomized rats.

Objectives: Oxidative stress is known to be involved in the pathogenesis of chronic renal failure (CRF). In this study, the effect of cyclodextrins (CDs) on oxidative stress and CRF was investigated using 5/6 nephrectomized rats as model animals.

Methods: CRF model rats were divided into five groups and treated for 8 weeks as follows: control, α-CD, β-CD, γ-CD and 2-hydroxypropyl-β-CD (HP-β-CD).

Formation of the ternary inclusion complex of limaprost with α- and β-cyclodextrins in aqueous solution.

The inclusion mode of Limaprost in the presence of α- and β-cyclodextrins (CDs) was investigated to gain insight into the stabilization mechanism of Limaprost-alfadex upon the addition of β-CD in the solid state. The inclusion sites of α- and β-CDs were studied by NMR spectroscopic and kinetic methods. With the addition of α- and β-CDs, displacements in (13)C chemical shifts of prostaglandin F2α (PGF2α) were observed in the ω-chain and the five-membered ring, respectively, of the drug.

Slow-release of famotidine from tablets consisting of chitosan/sulfobutyl ether β-cyclodextrin composites.

An intermolecular complex formed from a 1:1 weight ratio of chitosan (CS, molecular weight 30 kDa) and sulfobutyl ether β-cyclodextrin (SBE-β-CyD, degree of substitution 7) was less soluble than either of the original components. The release of famotidine from tablets composed of a simple mixture of CS and SBE-β-CyD is slower in media at pH 1.2 than at 6.

Preparation of hydrophilic C60(OH)10/2-hydroxypropyl-β-cyclodextrin nanoparticles for the treatment of a liver injury induced by an overdose of acetaminophen.

Stable hydrophilic C60(OH)10 nanoparticles were prepared from 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and applied to the treatment of an acetaminophen overdose induced liver Injury. C60(OH)10 nanoparticles were produced by cogrinding α-CD, β-CD, γ-CD and HP-β-CD and characterized in terms of solubility, mean particle diameter, ζ-potential and long term dispersibility in water. Hydrophilic C60(OH)10 nanoparticles with particle sizes less than 50 nm were effectively produced by cogrinding HP-β-CD with C60(OH)10 at a molar ratio of 1:3 (C60(OH)10:CD).

Effects of chitosan on oxidative stress and related factors in hemodialysis patients.

In recent world-wide studies, chitosans were tested as a dietary supplement for inhibiting the absorption of certain lipids and bile acids. We previously demonstrated the antioxidative and renoprotective potential of chitosan supplementation in chronic renal failure using 5/6 nephrectomized rats. In this study, we report the effects of chitosan on oxidative stress and related factors in hemodialysis patients.

Preparation and antioxidant activity of PEGylated chitosans with different particle sizes.

The preparation of water-soluble chitosans such as polyethylene glycol (PEG)-grafted derivatives is essential for improving the biocompatibility and water solubility of these types of polysaccharides. In this study, chitosans (CS1; 22 kDa, CS2; 38 kDa, CS3; 52 kDa) with different molecular weights were modified with a succinyl ester derivative of monomethoxypolyethylene glycol (mPEG-COONSu; 2 kDa), and the properties of the resulting conjugates (mPEG-CS1, mPEG-CS2, mPEG-CS3) were investigated. The antioxidant properties of these mPEG-CSs were examined using (1) N-centered radicals derived from 1,1'-diphenyl-2-picrylhydrazyl (DPPH), (2) reducing power, based on their ability to reduce Cu2+ and (3) hydroxyl radicals via the use of ESR spectrometry.

Stabilizing effect of β-cyclodextrin on Limaprost, a PGE₁ derivative, in Limaprost alfadex tablets (Opalmon) in highly humid conditions.

Stabilization against humidity of Limaprost (a prostaglandin E₁ derivative), which is currently marketed as Opalmon, was undertaken using β-cyclodextrin (β-CD). Aqueous solutions of Limaprost alfadex/dextran 40 were lyophilized with and without β-CD. Limaprost alfadex lyophilized with β-CD was more chemically stable in humid conditions than that without β-CD.

Cyclodextrins improve oral absorption of a novel factor Xa inhibitor by interfering with interaction between the drug and bile acids in rats.

Objectives: Poor oral absorption of a factor Xa inhibitor, DX-9065, is partly due to the interaction with bile acids in the gastrointestinal tract. The aim of this study is to improve the oral bioavailability of DX-9065 by cyclodextrins (CyDs) capable of interfering with such interaction.

Methods: The abilities of the CyDs to interfere with the interaction between DX-9065 and sodium chenodeoxycholate were evaluated using equilibrium dialysis.

Preparation of soluble stable C₆₀/human serum albumin nanoparticles via cyclodextrin complexation and their reactive oxygen production characteristics.

Aims: The stability of solutions of fullerene C₆₀ with human serum albumin (C₆₀/HSA) has not been studied in detail. In this study, we report on the preparation of stable C₆₀/HSA solutions that are formed via the formation of C₆₀/HP-β-CyD nanoparticles, i.e.

Crystallization of a new polymorph of acetohexamide from 2-hydroxybutyl-β-cyclodextrin solution: form VI with a high aqueous solubility.

A new polymorph of acetohexamide (Form VI) was prepared via the formation of a complex with 2-hydoxybutyl-β-cyclodextrin (HB-β-CD) in aqueous solution. An alkaline solution of acetohexamide and HB-β-CD was adjusted to pH 4.0 by titration with hydrochloric acid.

Antioxidant and renoprotective activity of chitosan in nephrectomized rats.

The effect of chitosan on oxidative stress and chronic renal failure was investigated using 5/6 nephrectomized rats. The ingestion of chitosan over a 4-week period resulted in a significant decrease in total body weight, glucose, serum creatinine and indoxyl sulfate levels (P=0.0011, P=0.

Possible enhancing mechanisms for gene transfer activity of glucuronylglucosyl-β-cyclodextrin/dendrimer conjugate.

We previously reported that glucuronylglucosyl-β-cyclodextrin (GUG-β-CyD) conjugate with polyamidoamine starburst dendrimer (GUG-β-CDE conjugate) with the average degree of substitution (DS) of cyclodextrin (CyD) of 1.8 (GUG-β-CDE conjugate (DS 1.8)), showed remarkably higher gene transfer activity than α-CyD/dendrimer conjugate (α-CDE conjugate (DS 1.

Evaluation of photodynamic activity of C60/2-hydroxypropyl-β-cyclodextrin nanoparticles.

The objective of this study is to evaluate the ability of C(60)/2-hydroxypropyl-β-cyclodextrin (HP-β-CyD) naonparticles to generate reactive oxygen species (ROS) and to induce cell toxicity by the photoirradiation. C(60) nanoparticles were prepared by cogrinding with HP-β-CyD for 3 h at 4°C under reduced pressure. The photodynamic activity of C(60)/HP-β-CyD nanoparticles was evaluated by spectroscopic methods, including the electron spin resonance spin-trapping method, and by the cell viability test using Hela cells.