Good Sustained Release Properties Research Articles

Preparation, optimisation, and properties of O-carboxymethyl chitosan-g-cholesterol succinic acid monoester polymer nanomicelles

Polymer nanomicelles have the advantages of small particle size, improved drug solubility, retention effect and enhanced permeability, so they can be used in the treatment of tumour diseases. The aim of this study was to prepare and optimise a nanomicelle which can improve the solubility of insoluble drugs. Firstly, the carboxyl group of cholesterol succinic acid monoester was grafted with the side chain amino group of O-carboxymethyl chitosan-g-cholesterol succinic acid monoester (CCMC), and its structure was characterized by fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H-NMR). Particle size has an important impact on tissue distribution, cell uptake, permeability and inhibition of tumour tissue. In this study, particle size and polydispersity index (PDI) were selected as indexes to optimise the preparation process of CCMC nanomicelles through single factor experiment, Plackett-Burman experiment, the steepest climbing experiment and response surface design experiment. The optimised CCMC nanomicelles showed an average particle size of 173.9 ± 2.3 nm and a PDI of 0.170 ± 0.053. The Cell Counting Kit-8 assay showed no significant effect on cell viability in the range of 0-1000 μg ml-1concentration. Coumarin-6 (C6) was used as a fluorescent probe to investigate the drug-carrying ability of CCMC nanomicelles. C6-CCMC showed 86.35 ± 0.56% encapsulation efficiency with a drug loading of 9.18 ± 0.32%. Both CCMC and C6-CCMC demonstrated excellent stability in different media. Moreover, under the same conditions, the absorption effect of C6 in C6-CCMC nanomicelles was significantly higher than that of free C6 while also exhibiting good sustained-release properties. Therefore, this study demonstrates CCMC nanomicelles as a promising new drug carrier that can significantly improve insoluble drug absorption.

Fabrication and characterization of TPGS-modified chlorogenic acid liposomes and its bioavailability in rats.

Chlorogenic acid (CGA), a polyphenol compound, exhibits excellent anti-oxidative, anti-hypoxic, antibacterial, antiviral, and anti-inflammatory activities, however the bioactivity of it has not been fully utilized in vivo due to its instability and low bioavailability. To address these issues, we prepared and characterized CGA-TPGS-LP, which is a TPGS-modified liposome loaded with CGA. The pharmacokinetics of CGA-TPGS-LP were studied in rats after oral administration. CGA-TPGS-LP was fabricated using a combination of thin film dispersion and ion-driven methods. The liposomes were observed to be uniformly small and spherical in shape. Their membranes were composed of lecithin, cholesterol, and TPGS lipophilic head with a TPGS hydrophilic tail chain coating on its surface. The loading efficiency and encapsulation efficiency were found to be 11.21% and 83.22%, respectively. The physicochemical characterisation demonstrated that the CGA was present in an amorphous form and retained its original structural state within the liposomal formulation. The stability of CGA was significantly improved by fabricating TPGS-LP. CGA-TPGS-LP exhibited good sustained-release properties in both simulated gastric and intestinal fluids. Following oral administration, ten metabolites were identified in rat plasma using UPLC-QTOF-MS. UPLC-QqQ-MS/MS quantitative analysis demonstrated that the oral bioavailability of CGA encapsulated in TPGS-modified liposomes was enhanced by 1.52 times. In addition, the three main metabolites of CGA had higher plasma concentrations and slower degradation rate. These results demonstrate that TPGS-modified liposomes could be a feasible strategy to further enhance the oral bioavailability of CGA, facilitating its clinical use.

A comparative study on stabilizing and releasing thymol by pre-formed V-type starch and β-cyclodextrin

Cyclodextrins (CD) are well known to form host-guest assemblies with hydrophobic compounds. As a structural homologue, starch-guest inclusion complexes (ICs) have become promising in the food, agriculture, and pharmaceutical industries due to their low cost and versatility. This study compared the stabilizing and releasing abilities for thymol of three kinds of pre-formed V-type starch (Water-V, Salt-V, and Alkali-V) and β-CD. The loading efficiency for thymol decreased in the order of Water-V > Alkali-V > CD > Salt-V when removing the free thymol. Water-V, β-CD, and their ICs had better thermal stability with maximum thermal decomposition temperatures over 320 °C. Under non-cold chain daily storage conditions for 4 d, the percentage of thymol released from starch/CD-thymol ICs was 14% (Water-V), 35% (Salt-V), 34% (Alkali-V), and 43% (CD). The Water-V made ICs had good sustained release properties and long-term antibacterial activity, which kept strawberries fresh for 6 d without decay.

Preparation and sustained-release of chitosan-alginate bilayer microcapsules containing aromatic compounds with different functional groups

This study investigated the release of aromatic compounds with distinct functional groups within bilayer microcapsules. Bilayer microcapsules of four distinctive core materials (benzyl alcohol, eugenol, cinnamaldehyde, and benzoic acid) were synthesized via freeze-drying. Chitosan (CS) and sodium alginate (ALG) were used as wall materials. CS concentration, using orthogonal experiments with the loading ratio as a metric. Under optimal conditions, three other types of microcapsules (cinnamic aldehyde, benzoic acid, and benzyl alcohol) were obtained. The four types of microcapsules were characterized using Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscope (TEM), and thermogravimetric analysis (TGA), and their sustained release characteristics were evaluated. The optimal conditions were: CS dosage, 1.2 %; CS-to-eugenol mass ratio, 1:2; and CS-to-ALG mass ratio, 1:1. By comparing the IR spectra of the four types of microcapsules, wall material, and core material, the core materials were revealed to be encapsulated within the wall material. SEM results revealed that the granular protuberances on the surface of the microcapsules were closely aligned and persistent when magnified 2000×. The TEM results indicated that all four microcapsules had a spherical and bilayer structure. The thermal stability and sustained release results showed that the four microcapsules were more resilient and less volatile than the four core materials. The release conformed to first-order kinetics, and the release ratios of the four microcapsules were as follows: benzyl alcohol microcapsules ˃ eugenol microcapsules ˃ cinnamaldehyde microcapsules ˃ benzoic acid microcapsules. The prepared bilayer microcapsules encapsulated four different core materials with good sustained release properties.

Fabrication of EGCG‐loaded Spirulina platensis microcarrier with sustained release properties and their application in extending the shelf‐life of minced lamb meat

SummaryIn the present study, epigallocatechin‐3‐gallate (EGCG)‐loaded Spirulina platensis (SP) microcarriers (SP@EGCG) were constructed and used to extend the shelf‐life of minced lamb meat as an antioxidant with good sustained release properties. Results showed that the encapsulation efficiency and encapsulation yield of SP@EGCG microcarriers were 91.19 ± 1.18% and 133.19 ± 1.34 μg mg−1, respectively. Results of fluorescence microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy and differential scanning calorimetry confirmed that the EGCG was successfully loaded in SP through hydrogen bonding interactions, and existing in an amorphous state. SP@EGCG displayed excellent antioxidant activity and stability. The SP@EGCG presented cumulative release in four food models (water, 3% acetic acid, 10% ethanol and 50% ethanol), and the cumulative release of SP@EGCG in 50% ethanol was the highest. These results indicated that SP can be used as a novel carrier of EGCG, and the prepared SP@EGCG microcarriers had potential applications in extending the shelf‐life of lamb meat.

Sustained release of a novel bilayer packaging film loaded with binary microemulsion of melatonin/pummelo essential oil and its regulation of postharvest energy metabolism in Agaricus bisporus

Bio-based active soft packaging materials have excellent potential to alleviate existing environmental problems caused by conventional packaging products and delay the postharvest aging of fruit and vegetables. In this study, a novel bilayer packaging film (G/T-M-E) of glutenin/tamarind gum loaded with binary microemulsion of melatonin/pummelo essential oil was prepared. The results indicated that the G/T-M-E packaging had superior barrier and mechanical properties. Importantly, the melatonin (MT) and pomelo essential oil (PEO) loaded in soft packaging had good sustained-release properties, which could ensure release characteristics in different food simulants. Among them, MT had the highest release efficiency in 10% ethanol, while PEO is more easily released in distilled water. Meanwhile, MT and PEO migrated from the packaging film from the inside-out via different diffusion effects, which was beneficial for the synergistic effect of active ingredients. G/T-M-E maintained a higher level of ATP of white mushrooms, greater energy charge levels and higher activity of succinate dehydrogenase (SDH) and cytochrome c oxidase (CCO). The energy charge (EC) of mushrooms packaged in G/T-M-E was as high as 0.65, which was 1.43 times higher than that of the G/T treatment group on day 12. The SDH and CCO activity of the G/T-M-E treatment group were 2.62 and 2.19 times higher than those of the G/T group on day 10, respectively. Overall, the G/T-M-E film improved the electron transfer efficiency, reduced the excess active oxygen content, maintained the high energy state, regulated the tricarboxylic acid cycle and electron transport chain pathways, indicating that the film has the active potential to regulate the energy state of postharvest mushrooms.

Emamectin-sodium alginate nano-formulation based on charge attraction with highly improved systemic translocation and photolysis resistance

Nano pesticides offer an effective means of improving the bioavailability of pesticide due to their excellent solubility and wettability, superior foliar adhesion, and permeability to target insects. By using high-speed homogenization and ultrasonic dispersion technology, an emamectin-sodium alginate nano-formulation (EB@SA) with a particle size ranging from 30 to 50 nm was successfully fabricated using electrostatic self-assembly. The microscopic morphology and structure of EB@SA were further analyzed through transmission electron microscopy, dynamic light scattering, infrared spectroscopy, and 1H NMR. The photolysis resistance behavior of EB@SA demonstrated an improved anti-photolysis ability more than double that of conventional formulations while also exhibiting good sustained-release properties. Not only does EB@SA maintain the inherent insecticidal toxicity of emamectin benzoate (EB), but it also significantly prolongs its insecticidal duration. At a concentration of 20 mg/L, the lethality rate against Armyworms remains above 70 % over a period of 16 days compared to <50 % for general emamectin emulsifiable concentrate. Furthermore, EB@SA greatly enhances the systemic translocation of EB in corn plants by exhibiting favorable bidirectional systemic translocation characteristics. This research presents an efficient and environmentally friendly pesticide nano-formulation that can be effectively utilized for field pest control.

Construction and properties of venlafaxine hydrochloride sustained release system based on hollow mesoporous silica microspheres

The aim of this work is to develop a venlafaxine hydrochloride sustained release system based on hollow mesoporous silica microspheres (HMSMs). HMSMs were innovatively prepared with tetraethyl silicate (TEOS) as the precursor and volatile n-heptane as a soft template. The obtained HMSMs show a well-defined hollow structure with an average size of 967 nm and pore volume of 0.85 cm3/g, implying it is a potential drug carrier. Subsequently, venlafaxine hydrochloride (VF) was absorbed in the HMSMs with a content of 37.67% or so. The sustained release effect is further measured by the dissolution instrument at 37 °C and 50 rpm in ultrapure water. The results showed that the HMSMs/VF system shows good sustained release properties compared with sustained release tablets with hydroxypropyl methylcellulose as the main component. This HMSMs sustained release system appears to be a promising candidate for a sustained drug release.

Disulfide Bridged Nanoparticles of Thiolated Sodium Alginate and Eudragit RS100 for Oral Delivery of Paclitaxel: In Vitro and In Vivo Evaluation.

Most biopharmaceutics classification system (BCS) class IV drugs have limited oral bioavailability due to poor solubility and poorer permeability. This work aims to investigate the possibility of utilizing disulfide bridged nanoparticles to improve BCS IV drug solubility and oral absorption. Disulfide bridged nanoparticles were made using thiolated sodium alginate (TSA) and thiolated eudragit RS100 (TERS100). This study used paclitaxel (PTL) as a model drug to create PTL-loaded nanoparticles using the air oxidation approach. PTL-loaded nanoparticles boosted the solubility of PTL by over 11 times (∼59 μg/mL). The nanoparticles had particle sizes of 103 nm, polydispersity indices of 0.034, and zeta potentials of -21 mV, respectively. Nanoparticles demonstrated 75.34% and 89.18% entrapment and loading efficiency of PTL, respectively. The PTL release data from nanoparticles had good sustained release properties. The effective permeability of PTL from nanoparticles was 2.19-fold higher than that of pure PTL suspension. The relative bioavailability of PTL with disulfide bridged nanoparticles was 237.11%, which was much higher than that of PTL suspension, according to the pharmacokinetic data. These results show that disulfide bridged nanoparticles have a wide range of clinical applications.

Development of polylactic-co-glycolic acid-polyethylene glycol nanoparticles as drug carriers to promote wound healing

Impaired wound healing is a common complication of orthopedic surgery and poses a difficult challenge in the clinic. Fibroblasts are thought to play a significant role in wound healing, and can be positively affected by low concentrations of rapamycin; however, rapamycin is cytotoxic at higher concentrations. To address this issue, a RAPA/PLGA-PEG drug delivery system was constructed in this study to maintain low concentrations of rapamycin. The results showed that the nanoparticles were stable, had good sustained drug release properties and were able to reduce the toxicity of rapamycin to fibroblasts. These findings suggest that RAPA/PLGA-PEG nanoparticles can reduce the cytotoxicity of rapamycin and may be a potential clinical treatment for impaired wound healing.

Development of Cationic Cellulose-Modified Bentonite-Alginate Nanocomposite Gels for Sustained Release of Alachlor.

The nanocomposite gel prepared from nanoclay and natural polysaccharides showed a good sustained-release property. Herein, a cationic cellulose-modified bentonite–alginate nanocomposite gel was prepared and used to enhance the sustained release of alachlor. The underlying effect and mechanism of the structure of modified bentonite–alginate nanocomposite gels on the release behavior of alachlor were explored by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric (TG) analysis. The results showed that the release of alachlor from the nanocomposite gels was dominated by Fickian diffusion and closely related to the adsorption capacity and permeability of the matrix. The cationic cellulose intercalated into the interlayer space of bentonite through an ion exchange reaction, which significantly enhanced the hydrophobicity of bentonite and its interaction with alachlor. The stacking aggregation of bentonite nanoplatelets and permeability of the gel network were decreased through the electrostatic interaction between cationic cellulose and alginate molecular chains, thus remarkably enhancing the sustained-release property of the nanocomposite gel. The release kinetics revealed that the release rate of alachlor from the nanocomposite gel first decreased and then increased as the content of bentonite and modified bentonite gradually increased. Also, the best sustained-release property of the nanocomposite gel was obtained at bentonite and modified bentonite additions of about 10%, under which the release time of 50% alachlor (T50) from bentonite–alginate and modified bentonite–alginate nanocomposite gels was 4.4 and 5.6 times longer than the release time from pure alginate gels, respectively.

Paclitaxel-Loaded TPGS2k/Gelatin-Grafted Cyclodextrin/Hyaluronic Acid-Grafted Cyclodextrin Nanoparticles for Oral Bioavailability and Targeting Enhancement

The clinical applications of paclitaxel (PTX), a natural compound with broad-spectrum antitumor effects, have been markedly limited owing to its poor oral bioavailability and lack of targeting ability. Recently, several drug carriers, such as TPGS2k, gelatin (Gel), cyclodextrin (CD), and hyaluronic acid (HA), have been identified as promising enhancers of drug efficacy. Therefore, Gel-grafted CD (GEL-CD) and HA-grafted CD (HA-CD) were synthesized via grafting, and PTX-loaded TPGS2k/GEL-CD/HA-CD nanoparticles (TGHC-PTX-NPs) were successfully prepared using the ultrasonic crushing method. The mean particles size, polydispersity index, and Zeta potential of TGHC-PTX-NPs were 253.57 ± 2.64 nm, 0.13 ± 0.03, and 0.087 ± 0.005 mV, respectively. TGHC-PTX-NPs with an encapsulation efficiency of 61.77 ± 0.47% and a loading capacity of 6.86 ± 0.32% appeared round and uniformly dispersed based on transmission electron microscopy. In vitro release data revealed that TGHC-PTX-NPs had good sustained-release properties. Further, TGHC-PTX-NPs had increased the targeted uptake by HeLa cells as HA can specifically bind to the CD44 receptor at the cell surface, and its intestinal absorption is related to caveolin-mediated endocytosis. The pharmacokinetic results indicated that TGHC-PTX-NPs significantly enhanced the absorption of PTX in vivo compared to the PTX suspension, with a relative bioavailability of 227.21%. Such findings indicate the potential of TGHC-PTX-NPs for numerous clinical applications.

Formulation, Characterization and Release Behaviour of Metformin Hydrochloride Modified Release Tablet by Using Hydrophilic Polymers

Amongst the many public health problems, the diabetes mellitus is considered as a chronic life-style related disease which is now growing as an epidemic in both developed as well as developing countries. The current study is about formulation of metformin hydrochloride tablet to confirm their sustained release property by using various polymers. The tablets are prepared by granulation techniques using binding solution containing polyvinyl pyrolline K30. The possible interaction between the pure metformin hydrochloride and polymers are identified by Fourier transform-infrared spectroscopy. Tablets were formulated with different polymers like Hydroxy propyl methyl cellulose K100 and sodium carboxymethyl cellulose. Matrix prepared with high concentration of HPMC K100 polymer retards the drug release up to 6 h at 59 %, but the formulation 2 (F2) showed 72.72% of drug release in 6 h. The release of drug from the F2 formulation was found to be prolonged drug release when compared to other formulations. Hence our study conclude that the HPMC K100 polymer containing formulation showed good sustained release property owing to the high gel strength and well high viscosity nature of the polymer.

Melamine-formaldehyde microcapsules encapsulating HEDP for sustained scale inhibition

Adding scale inhibitors is an efficient and economical solution to the troublesome scale deposition in various industrial productions. However, the direct use of liquid scale inhibitors often fails to provide long-term effective control and will cause a large amount of waste of scale inhibitors. Encapsulating the scale inhibitor into microcapsules is an advisable new approach to solving this problem. In this work, a water-soluble scale inhibitor (1-hydroxy ethylidene-1,1-diphosphonic acid, HEDP) was encapsulated into melamine formaldehyde microcapsules for the first time by in-situ polymerization using inverse emulsion (W/O emulsion) as a template. The influence of synthesis parameters (water-to-oil ratio, the amount of HEDP, stirring speed) on the morphology and particle size was investigated, and microcapsules with smooth surface, regular spherical shape and good dispersibility were obtained. The microcapsules possessed encapsulation efficiency exceeding 80% and good sustained-release properties (release time up to 63 h) ensuring sustainable scale inhibition. The scale inhibitor released from the microcapsules could inhibit the growth of calcium carbonate crystals and result in lattice distortion, which contributed to high scale inhibition efficiency (about 86%). The prepared microcapsules have broad application prospects in the field of industrial scale inhibition. • A new way to use scale inhibitors, encapsulation of scale inhibitors, was provided. • A water-soluble scale inhibitor was successfully encapsulated into microcapsules. • Melamine-formaldehyde shell was used to encapsulate aqueous solution. • The microcapsules possessed high encapsulation efficiency. • The microcapsules possessed high scale inhibition efficiency.

Preparation and Antimicrobial Activity of Antibacterial Silver-Loaded Polyphosphazene Microspheres.

Poly(cyclotriphosphazene-co-4,4'-diaminodiphenyl ether) (PPO) microspheres were prepared via a precipitation polymerization method, using hexachlorocyclotriphosphazene (HCCP) and 4,4'-diaminodiphenyl ether (ODA) as monomers. Silver-loaded PPO (PPOA) microspheres were generated by the in situ loading of silver nanoparticles onto the surface by Ag+ reduction. Our results showed that PPOA microspheres were successfully prepared with a relatively uniform distribution of silver nanoparticles on microsphere surfaces. PPOA microspheres had good thermal stability and excellent antibacterial activity towards Escherichia coli and Staphylococcus aureus. Furthermore, PPOA microspheres exhibited lower cytotoxicity when compared to citrate-modified silver nanoparticles (c-Ag), and good sustained release properties. Our data indicated that polyphosphazene-based PPOA microspheres are promising antibacterial agents in the biological materials field.

The Molecular Structure and Self-Assembly Behavior of Reductive Amination of Oxidized Alginate Derivative for Hydrophobic Drug Delivery.

On account of the rigid structure of alginate chains, the oxidation-reductive amination reaction was performed to synthesize the reductive amination of oxidized alginate derivative (RAOA) that was systematically characterized for the development of pharmaceutical formulations. The molecular structure and self-assembly behavior of the resultant RAOA was evaluated by an FT-IR spectrometer, a 1H NMR spectrometer, X-ray diffraction (XRD), thermal gravimetric analysis (TGA), a fluorescence spectrophotometer, rheology, a transmission electron microscope (TEM) and dynamic light scattering (DLS). In addition, the loading and in vitro release of ibuprofen for the RAOA microcapsules prepared by the high-speed shearing method, and the cytotoxicity of the RAOA microcapsules against the murine macrophage RAW264.7 cell were also studied. The experimental results indicated that the hydrophobic octylamine was successfully grafted onto the alginate backbone through the oxidation-reductive amination reaction, which destroyed the intramolecular hydrogen bond of the raw sodium alginate (SA), thereby enhancing its molecular flexibility to achieve the self-assembly performance of RAOA. Consequently, the synthesized RAOA displayed good amphiphilic properties with a critical aggregation concentration (CAC) of 0.43 g/L in NaCl solution, which was significantly lower than that of SA, and formed regular self-assembled micelles with an average hydrodynamic diameter of 277 nm (PDI = 0.19) and a zeta potential of about −69.8 mV. Meanwhile, the drug-loaded RAOA microcapsules had a relatively high encapsulation efficiency (EE) of 87.6 % and good sustained-release properties in comparison to the drug-loaded SA aggregates, indicating the good affinity of RAOA to hydrophobic ibuprofen. The swelling and degradation of RAOA microcapsules and the diffusion of the loaded drug jointly controlled the release rate of ibuprofen. Moreover, it also displayed low cytotoxicity against the RAW264.7 cell, similar to the SA aggregates. In view of the excellent advantages of RAOA, it is expected to become the ideal candidate for hydrophobic drug delivery in the biomedical field.

Antiproliferative drug-loaded multi-functionalized intraocular lens for reducing posterior capsular opacification

Posterior capsule opacification (PCO) is one of the most frequent complications in cataract surgery and likely to cause the second loss of vision. Proliferation and migration of postoperative remnants of lens epithelial cells (LECs) on the implanted intraocular lens (IOL) are the leading causes of PCO. Antiproliferative drugs can be an effective solution but also possess some problems including sudden release and accompanying adverse effects to surrounding normal tissues, which greatly limit the clinical trials. In this study, an antiproliferative drug Paclitaxel (Pac) -sustained released hyaluronic acid (HA) and chitosan (CHI) multilayer modified IOL with postoperatively long-term PCO prevention was fabricated via layer by layer (LbL) technique. Quartz crystal microbalance with dissipation monitoring (QCM-D) result shows that HA-Pac/CHI multilayer is modified onto IOL material via LbL technique successfully. The HA-Pac/CHI multilayer coating greatly improves the hydrophilicity of the IOL material surfaces without change the transmittance significantly, whereas the proliferation of LECs is distinctly reduced on the HA-Pac/CHI multilayer-modified surfaces. The drug release in vitro reveals that the multilayer modified IOL material is stable under physiological condition and has good sustained drug release property. All these results demonstrate that HA-Pac/CHI multilayer modified IOL material can effectively inhibit LECs proliferation which provides a novel approach for reducing of PCO incidence in clinical.

Carboxymethyl chitosan microspheres loaded hyaluronic acid/gelatin hydrogels for controlled drug delivery and the treatment of inflammatory bowel disease

A major drawback of oral treatment of inflammatory bowel disease (IBD) is the non-specific distribution of drugs during long-term treatment. Despite its effectiveness as an anti-inflammatory drug, curcumin (CUR) is limited by its low bioavailability in IBD treatment. Herein, a pH-sensitive composite hyaluronic acid/gelatin (HA/GE) hydrogel drug delivery system containing carboxymethyl chitosan (CC) microspheres loaded with CUR was fabricated for IBD treatment. The composition and structure of the composite system were optimized and the physicochemical properties were characterized using infrared spectroscopy, X-ray diffraction, swelling, and release behavior studies. In vitro, the formulation exhibited good sustained release property and the drug release rate was 65% for 50 h. In vivo pharmacokinetic experiments indicated that high level of CUR was maintained in the colon tissue for more than 24 h; it also played an anti-inflammatory role by evaluating the histopathological changes through hematoxylin and eosin (H&E), myeloperoxidase (MPO), and immunofluorescent staining. Additionally, the formulation substantially inhibited the level of the main pro-inflammatory cytokines of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) secreted by macrophages, compared to the control group. The pharmacodynamic experiment showed that the formulation group of CUR@gels had the best therapeutic effect on colitis in mice. The composite gel delivery system has potential for the effective delivery of CUR in the treatment of colitis. This study also provides a reference for the design and preparation of a new oral drug delivery system with controlled release behavior.

Preparation of a novel sustained-release system for pyrethroids by using metal-organic frameworks (MOFs) nanoparticle

In recent years, metal-organic frameworks (MOFs), especially nanoscale metal-organic frameworks (NMOFs) have been arisen as potential platform for delivery and sustained-release of drug molecules due to their excellent encapsulation performance. While, NMOFs used as carriers for pesticides have rarely been reported. Nanoscale UiO-66 had the potential to be used as a pesticide carrier due to its outstanding chemical and thermal stability, non-toxic and mass-production. In this work, lambda-cyhalothrin (LC) molecules were encapsulated in the nanoscale UiO-66 (LC@UiO-66) with ultrahigh drug loading (87.71 %) and good sustained-release property. The drug loading of LC@UiO-66 was higher than that of ever reported. LC@UiO-66 nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis measurements (TGA) and nitrogen adsorption-desorption isotherms. LC@UiO-66 nanoparticles had the cubic shape with an average particle size around 270 nm. The bioassay against Musca domestica (hygiene pests) showed that LC@UiO-66 had long-term insecticidal effect compared to the free LC and commercially available microcapsules, and the insecticidal activity of LC@UiO-66 was superior to commercially available microcapsules. Furthermore, LC@UiO-66 had an effective insecticidal effect against Aphis craccivora Koch (agricultural pests). All the above results demonstrated that LC@UiO-66 had excellent insecticidal effect in both public hygiene and agriculture. This study could expand the application of NMOFs as novel carriers for pesticides.

Inulin-Grafted Stearate (In-g-St) as the Effective Self-Assembling Polymeric Micelle: Synthesis and Evaluation for the Delivery of Betamethasone

Background. Betamethasone as a corticosteroid drug is commonly used for the treatment of rheumatoid arthritis. Unfortunately, betamethasone is a low water-soluble drug and its efficacy is low. So an attractive strategy is the targeted delivery of betamethasone to the damaged joint using polymeric micelle-based carriers. Methods. Inulin-grafted stearate (In-g-St) was synthesized via the reaction of stearoyl chloride and inulin, then characterized by FT-IR and H-NMR. In-g-St forms micelles in the presence of betamethasone. The prepared polymeric micelles were characterized for size, zeta potential, drug loading, particles’ morphology, critical micelle concentration (CMC), and encapsulation efficiency. So sustained release polymeric micelles of betamethasone were developed by employing In-g-St. Results. The measurement of particle size showed a mean diameter of 60 and 130 nm for 10% and 20% drug-loaded micelles, respectively, and SEM showed that the particle’s morphologies are spherical. Zeta potential measurement for the drug-containing micelles showed a value of -11.8 mV. Drug loading efficiency and the encapsulation efficiency were 6.36% and 63.6%, as well as 18.97% and 94.88% for 10% and 20%, respectively. 20% drug-loaded polymer showed a small burst release of betamethasone at the first 3 h which was followed by sustained release in the next 24 h. Furthermore, the formula with 10% exhibited good sustained release properties except for the minor initial burst release. Conclusion. Data from the zeta potential, CMC, drug loading capacity, and in vitro drug release studies indicated that In-g-St polymeric micelles can be suitable candidates for the efficient delivery of hydrophobic drugs like betamethasone.