Electrospun coaxial hyaluronan-based fiber networks for ophthalmic drug release

2021 ◽  
Vol 7 (2) ◽  
pp. 688-691
Author(s):  
Torsten Walter ◽  
Ralf Wyrwa ◽  
Cindy Altmann ◽  
Matthias Schnabelrauch
Keyword(s):  
Drug Release ◽  
Inner Core ◽  
Coaxial Electrospinning ◽  
Burst Release ◽  
Fiber Networks ◽  
Time Period ◽  
Release Device ◽  
Release Studies ◽  
Ophthalmic Drug ◽  
Core Phase

Abstract A micro-sized core-shell drug release device has been prepared by coaxial electrospinning based on a polylactide shell and the inner core phase made of high molecular weight hyaluronan or a cross-linked hyaluronan network. Timolol, which was inserted into the core phase, is widely used as drug for glaucoma treatment to depress the intraocular eye pressure and should be released over a longer time period from this fiber networks. Release studies of drug loaded fiber devices showed an only moderate burst release of timolol in the first days followed by a continuous longlasting drug release period over several weeks. With these findings, coaxial electrospinning represents a promising approach for the development of drug release systems with long-lasting, relatively constant drug delivery.

scholarly journals Modification of Ceiba pentandra cellulose for drug release applications

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 194-202
Author(s):  
Silvia Argelia Peraza-Ku ◽  
José Manuel Cervantes-Uc ◽  
Beatriz Escobar-Morales ◽  
Jorge Alonso Uribe-Calderon
Keyword(s):  
Drug Release ◽  
Release Kinetics ◽  
Cross Linking ◽  
Burst Release ◽  
Tetracarboxylic Acid ◽  
Ceiba Pentandra ◽  
Release Studies ◽  
The Cross ◽  
The Fourier Transform

AbstractTubular fibers (raw and wax-free) from Ceiba pentandra (CP) were cross-linked with butane-1,2,3,4-tetracarboxylic acid (BTCA) at different concentrations to obtain a porous biodegradable medium for drug release applications. Chlorhexidine diacetate (CHX) was added to the cross-linked fibers for drug release studies. The Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy results indicated that the cross-linked fibers with a 5:1 fiber:BTCA ratio presented the higher cross-linking density. CHX was added at different concentrations (8% and 16% wt/wt); the elemental analysis indicated that CHX was loaded up to 7.99 wt%. In vitro studies showed a burst release of CHX within the first 3 h. CHX release kinetics was described using several models, with the Korsmeyer–Peppas equation, which adjusted better to the experimental data. The results indicated that the CP fibers are a feasible material for drug release applications.

scholarly journals Synthesis, Degradation, Biocompatibility and Drug Release Studies of Bis 2-Hydroxy Ethyl Terephthalate-based Poly(Mannitol-Citric-Sebacate) Ester

2016 ◽  
Vol 1 (1) ◽  
pp. 9-16
Author(s):  
Athira K Sunil ◽  
Sarkar K ◽  
Kaushik Chatterjee
Keyword(s):  
Drug Release ◽  
Drug Carrier ◽  
Condensation Process ◽  
Burst Release ◽  
Release Studies ◽  
Biodegradable Poly ◽  
Model Drug ◽  
Melt Condensation

Bis 2-Hydroxy Ethyl Terephthalate-based biodegradable poly(mannitol-citric-sebacate) has been synthesized by catalyst-free melt condensation process using two different diacids and Bis 2-Hydroxy Ethyl Terephthalate with D-mannitol as monomers having a potential to be metabolized in vivo. The biocompatibility of the polymer, Bis 2-Hydroxy Ethyl Terephthalate-poly(mannitol-citric-sebacate) has been tested using human primary stromal cells. In vitro degradation of Bis 2-Hydroxy Ethyl Terephthalate-poly(mannitol-citric-sebacate) polymer in Phosphate Buffered Saline solution carried out at physiological conditions indicates that the degradation goes to completion after 23 days. The usage of Bis 2-Hydroxy Ethyl Terephthalate-poly(mannitol-citric-sebacate) polymer as a drug carrier has been analyzed by doping the polymer with Doxorubicin model drug and the release rate has been studied by mass loss over time. The cumulative drug-release profiles exhibit a biphasic release with an initial burst release and cumulative 100 percent release within 14 days.

Biodegradable Amphiphilic Tri-Block Copolymeric Nanoparticles for Controlled MTB Drug Delivery

2012 ◽  
Vol 584 ◽  
pp. 460-464 ◽  
Author(s):  
M Gajendiran ◽  
S. Balasubramanian
Keyword(s):  
Drug Release ◽  
Drug Loading ◽  
Powder Xrd ◽  
Burst Release ◽  
In Vitro Drug Release ◽  
Drug Content ◽  
Loading Efficiency ◽  
Release Studies ◽  
Drug Loading Efficiency

. A series of biodegradable amphiphilic tri-block copolymers (PLGA–PEG–PLGA) have been derived from the diblock copolymer poly (lactic–co–glycolic acid (PLGA)) and polyethylene glycol (PEG). The mycobacterium tuberculosis (MTB) drug pyrazinamide (PZA) loaded polymer nanoparticles (NPs) have been prepared by probe-sonication followed by w/o/w double emulsification technique. The copolymers have been characterized by FTIR and 1HNMR spectroscopic techniques, TG-DTA analysis, GPC analysis and powder XRD pattern. The MTB drug loaded polymeric NPs have been characterized by FESEM, powder XRD, HRTEM and XPS analysis. The drug loading efficiency, drug content and in vitro drug release studies have been carried out by spectrophotometry. The drug loading efficiency and drug content of triblock copolymeric NPs were higher than these of diblock copolymeric microparticles (MPs). The in vitro drug release studies indicate that the NPs exhibit initial burst release followed by controlled release of PZA for longer durations. The drug release kinetics mechanism has been evaluated by zero order, first order, Korsemeyer-Peppas (KP) and Higuchi models.

Synthesis, Characterization and in-vitro drug release studies of a macromolecular prodrug of Didanosine.

2010 ◽  
Vol 2 (2) ◽  
Author(s):  
Neeraj Agrawal ◽  
M.J. Chandrasekar ◽  
U.V. Sara ◽  
Rohini A.
Keyword(s):  
Drug Release ◽  
Drug Level ◽  
Drug Release Profile ◽  
Sustained Drug Release ◽  
In Vitro Drug Release ◽  
Alkaline Environment ◽  
Stomach Acid ◽  
Release Studies ◽  
Macromolecular Prodrug

A macromolecular prodrug of didanosine (ddI) for oral administration was synthesized and evaluated for in-vitro drug release profile. Didanosine was first coupled to 2-hydroxy ethyl methacrylate (HEMA) through a succinic spacer to form HEMA-Suc-ddI monomeric conjugate which was subsequently polymerized to yield Poly(HEMA-Suc-ddI) conjugate. The structures of the synthesized compounds were characterized by FT-IR, Mass and 1H-NMR spectroscopy. The prodrug was subjected for in-vitro drug release studies in buffers of pH 1.2 and 7.4 mimicking the upper and lower GIT. The results showed that the drug release from the polymeric backbone takes place in a sustained manner over a period of 24 h and the amount of drug released was comparatively higher at pH 7.4 indicating that the drug release takes place predominantly at the alkaline environment of the lower GIT rather than at the acidic environment of the upper GIT. This pH dependent sustained drug release behavior of the prodrug may be capable of reducing the dose limiting toxicities by maintaining the plasma drug level within the therapeutic range and increasing t1/2 of ddI. Moreover, the bioavailability of the drug should be improved as the prodrug releases ddI predominantly in the alkaline environment which will reduce the degradation of ddI in the stomach acid.

Utilization of a Single Experimental Design for the Optimization of Furosemide Modified-Release Tablet Formulations

2019 ◽  
Vol 16 (10) ◽  
pp. 931-939
Author(s):  
Marilena Vlachou ◽  
Angeliki Siamidi ◽  
Yannis Dotsikas
Keyword(s):  
Experimental Design ◽  
Drug Release ◽  
Burst Release ◽  
Dissolution Profile ◽  
Modified Release ◽  
Lactose Monohydrate ◽  
Bilayer Tablets ◽  
Combined Design ◽  
Tablet Formulations ◽  
Optimal Combined Design

Background: The loop diuretic drug furosemide is widely used for the treatment of edema in various conditions, such as pulmonary, cardiac and hepatic edema, as well as cardiac infarction. Furosemide, due to its poor water solubility and low bioavailability after oral administration of conventional dosage form, is categorized as class IV in the biopharmaceutical classification system. Objective: In the case of furosemide, this release profile is responsible for various physiological problems, acute diuresis being the most serious. This adverse effect can be circumvented by the modified release of furosemide from tablet formulations compared to those forms designed for immediate release. Method: In this report, a D-optimal combined experimental design was applied for the development of furosemide containing bilayer and compression coated tablets, aiming at lowering the drug’s burst release in the acidic environment of the stomach. A D-optimal combined design was selected in order to include all requirements in one design with many levels for the factors examined. The following responses were selected as the ones reflecting better criteria for the desired drug release: dissolution at 120 min (30-40%), 300 min (60-70%) and 480 min >95%. The new formulations, suggested by the Doptimal combined design, incorporated different grades of Eudragit ® polymers (Eudragit® E100 and Eudragit® L100-55), lactose monohydrate and HPMC K15M. The dissolution profile of furosemide from these systems was probed via in vitro dissolution experiments in buffer solutions simulating the pH of the gastrointestinal tract. Results: The results indicate that the use of Eudragit® E100 in conjunction with lactose monohydrate led to 21.32-40.85 % drug release, in the gastric medium, in both compression-coated and bilayer tablets. This is lower than the release of the mainstream drug Lasix® (t=120 min, 44.5% drug release), implying longer gastric retention and drug waste minimization. Conclusion: Furosemide’s release in the intestinal environment, from compression coated tablets incorporating Eudragit® L100-55 and HPMC K15M in the inner core or one of the two layers of the bilayer tablets, was delayed, compared to Lasix®

scholarly journals Chitosan/Silver Nanoparticle/Graphene Oxide Nanocomposites with Multi-Drug Release, Antimicrobial, and Photothermal Conversion Functions

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2351
Author(s):  
Zheng Su ◽  
Daye Sun ◽  
Li Zhang ◽  
Miaomiao He ◽  
Yulin Jiang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Graphene Oxide ◽  
Drug Release ◽  
Release Rate ◽  
Composite System ◽  
Methyl Blue ◽  
Burst Release ◽  
Fluorescein Sodium ◽  
Photothermal Conversion ◽  
Dual Drug

In this work, we designed and fabricated a multifunctional nanocomposite system that consists of chitosan, raspberry-like silver nanoparticles, and graphene oxide. The room temperature atmospheric pressure microplasma (RT-APM) process provides a rapid, facile, and environmentally-friendly method for introducing silver nanoparticles into the composite system. Our composite can achieve a pH controlled single and/or dual drug release. Under pH 7.4 for methyl blue loaded on chitosan, the drug release profile features a burst release during the first 10 h, followed by a more stabilized release of 70–80% after 40–50 h. For fluorescein sodium loaded on graphene oxide, the drug release only reached 45% towards the end of 240 h. When the composite acted as a dual drug release system, the interaction of fluorescein sodium and methyl blue slowed down the methyl blue release rate. Under pH 4, both single and dual drug systems showed a much higher release rate. In addition, our composite system demonstrated strong antibacterial abilities against E. coli and S. aureus, as well as an excellent photothermal conversion effect under irradiation of near infrared lasers. The photothermal conversion efficiency can be controlled by the laser power. These unique functionalities of our nanocomposite point to its potential application in multiple areas, such as multimodal therapeutics in healthcare, water treatment, and anti-microbials, among others.

Synthesis and characterization of Chitosan-Catechol conjugates: Development and in vitro, in silico and in vivo evaluation of mucoadhesive pellets of lafutidine

2021 ◽  
pp. 088391152199784
Author(s):  
Loveleen Kaur ◽  
Ajay Kumar Thakur ◽  
Pradeep Kumar ◽  
Inderbir Singh
Keyword(s):  
Drug Release ◽  
In Silico ◽  
Ex Vivo ◽  
Strong Interactions ◽  
Dissolution Time ◽  
Sem Images ◽  
In Vivo Evaluation ◽  
Release Studies

Present study was aimed to synthesize and characterize Chitosan-Catechol conjugates and to design and develop mucoadhesive pellets loaded with lafutidine. SEM images indicated the presence of fibrous structures responsible for enhanced mucoadhesive potential of Chitosan-Catechol conjugates. Thermodynamic stability and amorphous nature of conjugates was confirmed by DSC and XRD studies respectively. Rheological studies were used to evaluate polymer mucin interactions wherein strong interactions between Chitosan-Catechol conjugate and mucin was observed in comparison to pristine chitosan and mucin. The mucoadhesion potential of Chitosan-Catechol (Cht-C) versus Chitosan (Cht) was assessed in silico using molecular mechanics simulations and the results obtained were compared with the in vitro and ex vivo results. Cht-C/mucin demonstrated much higher energy stabilization (∆E ≈ −65 kcal/mol) as compared to Cht/mucin molecular complex. Lafutidine-loaded pellets were prepared from Chitosan (LPC) and Chitosan-Catechol conjugates (LPCC) and were evaluated for various physical properties viz. flow, circularity, roundness, friability, drug content, particle size and percent mucoadhesion. In vitro drug release studies on LPC and LPCC pellets were performed for computing t50%, t90% and mean dissolution time. The values of release exponent from Korsmeyer-Peppas model was reported to be 0.443 and 0.759 for LPC and LPCC pellets suggesting Fickian and non-Fickian mechanism representing drug release, respectively. In vivo results depicted significant controlled release and enhanced residence of the drug after being released from the chitosan-catechol coated pellets. Chitosan-Catechol conjugates were found to be a promising biooadhesive polymer for the development of various mucoadhesive formulations.

scholarly journals Development of Controlled-Release Carbamide Peroxide Loaded Nanoemulgel for Tooth Bleaching: In Vitro and Ex Vivo Studies

2021 ◽  
Vol 14 (2) ◽  
pp. 132
Author(s):  
Siriporn Okonogi ◽  
Adchareeya Kaewpinta ◽  
Sakornrat Khongkhunthian ◽  
Pisaisit Chaijareenont
Keyword(s):  
Drug Release ◽  
Solid Dispersion ◽  
Solid Dispersions ◽  
Tooth Bleaching ◽  
Polymer Mixture ◽  
Release Mechanism ◽  
Burst Release ◽  
Order Kinetic ◽  
Carbamide Peroxide ◽  
Periodontal Tissues

Burst release of carbamide peroxide (CP) from traditional hydrogels causes severe inflammation to periodontal tissues. The present study explores the development of a novel CP nanoemulgel (CP-NG), an oil-in-water nanoemulsion-based gel in which CP was loaded with a view to controlling CP release. CP solid dispersions were prepared, using white soft paraffin or polyvinylpyrrolidone-white soft paraffin mixture as a carrier, prior to formulating nanoemulsions. It was found that carrier type and the ratio of CP to carrier affected drug crystallinity. Nanoemulsions formulated from the optimized CP solid dispersions were used to prepare CP-NG. It was found that the ratio of drug to carrier in CP solid dispersions affected the particle size and zeta potential of the nanoemulsions as well as drug release behavior and tooth bleaching efficacy of CP-NG. Drug release from CP-NG followed a first-order kinetic reaction and the release mechanism was an anomalous transport. Drug release rate decreased with an increase in solid dispersion carriers. CP-NG obtained from the solid dispersion with a 1:1 ratio of CP to the polymer mixture is suitable for sustaining drug release with high tooth bleaching efficacy and without reduction of enamel microhardness. The developed CP-NG is a promising potential tooth bleaching formulation.

scholarly journals Novel Hydrogels of Chitosan and Poly (vinyl alcohol) Reinforced with Inorganic Particles of Bioactive Glass

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 691
Author(s):  
O. Sánchez-Aguinagalde ◽  
Ainhoa Lejardi ◽  
Emilio Meaurio ◽  
Rebeca Hernández ◽  
Carmen Mijangos ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Drug Release ◽  
Bioactive Glass ◽  
Vinyl Alcohol ◽  
Release Kinetics ◽  
The Body ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
Inorganic Particles ◽  
Release Studies

Chitosan (CS) and poly (vinyl alcohol) (PVA) hydrogels, a polymeric system that shows a broad potential in biomedical applications, were developed. Despite the advantages they present, their mechanical properties are insufficient to support the loads that appear on the body. Thus, it was proposed to reinforce these gels with inorganic glass particles (BG) in order to improve mechanical properties and bioactivity and to see how this reinforcement affects levofloxacin drug release kinetics. Scanning electron microscopy (SEM), X-ray diffraction (XRD), swelling tests, rheology and drug release studies characterized the resulting hydrogels. The experimental results verified the bioactivity of these gels, showed an improvement of the mechanical properties and proved that the added bioactive glass does affect the release kinetics.

Nondestructive Analysis of Dragonfly Eye Beads from the Warring States Period, Excavated from a Chu Tomb at the Shenmingpu Site, Henan Province, China

2013 ◽  
Vol 19 (2) ◽  
pp. 335-343 ◽  
Author(s):  
Yimin Yang ◽  
Lihua Wang ◽  
Shuya Wei ◽  
Guoding Song ◽  
Jonathan Mark Kenoyer ◽  
...  
Keyword(s):  
Inner Core ◽  
Nondestructive Method ◽  
Henan Province ◽  
Manufacturing Technology ◽  
Warring States Period ◽  
Warring States ◽  
Time Period ◽  
Mold Casting ◽  
Warring State Period ◽  
Manufacturing Features

AbstractDragonfly eye beads are considered to be the earliest types of glass objects in China, and in the past have been considered as evidence of culture interaction or trade between West and East Asia. In this article, synchrotron radiation microcomputed tomography and μ-probe energy dispersive X-ray fluorescence were used to determine the chemical composition, microstructure, and manufacturing technology of four dragonfly eye beads, excavated from a Chu tomb at the Shenmingpu site, Henan Province, China, dated stylistically to the Middle and Late Warring State Period (475 bc–221 bc). First, a nondestructive method was used to differentiate the material types including faience (glazed quartz), frit, glazed pottery (clay ceramic), and glass. Three beads were identified as faience and one bead as glazed pottery. The glaze recipe includes quartz, saltpeter, plant ash, and various copper, and is classified as belonging to the K2O-CaO-SiO2 glass system, which indicates that these beads were not imported from the West. Based on computed tomography slices, the manufacturing technology of the faience eye beads appears to include the use of an inner core, molding technology, and the direct application glazing method. These manufacturing features are consistent with the techniques used in China during this same time period for bronze mold-casting, proto-porcelain, and glass.

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