scholarly journals Rapid controlled release by photo-irradiation using morphological changes in micelles formed by amphiphilic lophine dimers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Masaaki Akamatsu ◽  
Kazuki Kobayashi ◽  
Hiroki Iwase ◽  
Yoshifumi Sakaguchi ◽  
Risa Tanaka ◽  
...  
Keyword(s):  
Controlled Release ◽  
Morphological Changes ◽  
Molecular Assembly ◽  
Active Components ◽  
Molecular Assemblies ◽  
On Demand ◽  
Photoresponsive Surfactants ◽  
Rapid Control ◽  
Ultraviolet Light Irradiation ◽  
Model Drug

AbstractPhoto-induced rapid control of molecular assemblies, such as micelles and vesicles, enables effective and on-demand release of drugs or active components, with applications such as drug delivery systems (DDS) and cosmetics. Thus far, no attempts to optimize the responsiveness of photoresponsive molecular assemblies have been published. We previously reported photoresponsive surfactants bearing a lophine dimer moiety that exhibit fast photochromism in confined spaces, such as inside a molecular assembly. However, rapid control of the micelle structures and solubilization capacity have not yet been demonstrated. In the present work, photo-induced morphological changes in micelles were monitored using in-situ small-angle neutron scattering (SANS) and UV/Vis absorption spectroscopy. An amphiphilic lophine dimer (3TEG-LPD) formed elliptical micelles. These were rapidly elongated by ultraviolet light irradiation, which could be reversed by dark treatment, both within 60 s. For a solution of 3TEG-LPD micelles solubilizing calcein as a model drug molecule, fluorescence and SANS measurements indicated rapid release of the incorporated calcein into the bulk solvent under UV irradiation. Building on these results, we investigated rapid controlled release via hierarchical chemical processes: photoisomerization, morphological changes in the micelles, and drug release. This rapid controlled release system allows for effective and on-demand DDS.

scholarly journals 3D Printing of Temporary Prostheses for Controlled-Release of Drugs: Design, Physical Characterization and Preliminary Studies

2021 ◽  
Vol 14 (12) ◽  
pp. 1240
Author(s):  
Carlos Bueno-López ◽  
Carlos Tamarit-Martínez ◽  
Adrián M. Alambiaga-Caravaca ◽  
Cristina Balaguer-Fernández ◽  
Virginia Merino ◽  
...  
Keyword(s):  
Controlled Release ◽  
3D Printing ◽  
Morphological Changes ◽  
Release Kinetics ◽  
Cylindrical Structures ◽  
Joint Replacement Surgery ◽  
Replacement Surgery ◽  
Continue Research ◽  
3D Printed ◽  
Model Drug

In recent years, the use of 3D printing technologies in orthopedic surgery has markedly increased, as they offer the possibility of printing personalized prostheses. The work presented in this article is a preliminary study of a research project which aims to manufacture customized spacers containing antibiotics for use in joint replacement surgery. The objective of this work was to design and print different 3D constructs to evaluate the use of different materials, their properties after the process of 3D printing, such as resistance, and the release kinetics of drugs from the constructs. Different designs and different materials were analyzed to obtain a 3D construct with suitable properties. Our design takes advantage of the micropores created between the layers of the 3D printed filaments to release the contained drug. Using polylactic acid (PLA) we were able to print cylindrical structures with interconnected micropores and a hollow chamber capable of releasing methylene blue, which was selected as a model drug. The final PLA 3D construct was printed with a 10% infill. The physical and technological characteristics, morphological changes at body temperature and interaction with water were considered to be acceptable. The PLA 3D printed constructs were found to have sufficient strength to withstand a force of 500 kg. The results obtained allow to continue research in this project, with the aim of manufacturing prostheses containing a reservoir of antibiotics or other drugs in their interior for their subsequent controlled release.

Controlled Release of Metformin Hydrochloride I. In vitro Release from Physical Mixture Containing Xanthan Gum as Hydrophilic Rate Retarding Polymer

1970 ◽  
Vol 4 (1) ◽  
Author(s):  
Mashkura Ashrafi ◽  
Jakir Ahmed Chowdhury ◽  
Md Selim Reza
Keyword(s):  
Controlled Release ◽  
Xanthan Gum ◽  
In Vitro Release ◽  
Correlation Coefficients ◽  
High Ratio ◽  
Water Soluble ◽  
Metformin Hydrochloride ◽  
Model Drug ◽  
Very High

Capsules of different formulations were prepared by using a hydrophilic polymer, xanthan gum and a filler Ludipress. Metformin hydrochloride, which is an anti-diabetic agent, was used as a model drug here with the aim to formulate sustained release capsules. In the first 6 formulations, metformin hydrochloride and xanthan gum were used in different ratio. Later, Ludipress was added to the formulations in a percentage of 8% to 41%. The total procedure was carried out by physical mixing of the ingredients and filling in capsule shells of size ‘1’. As metformin hydrochloride is a highly water soluble drug, the dissolution test was done in 250 ml distilled water in a thermal shaker (Memmert) with a shaking speed of 50 rpm at 370C &plusmn 0.50C for 6 hours. After the dissolution, the data were treated with different kinetic models. The results found from the graphs and data show that the formulations follow the Higuchian release pattern as they showed correlation coefficients greater than 0.99 and the sustaining effect of the formulations was very high when the xanthan gum was used in a very high ratio with the drug. It was also investigated that the Ludipress extended the sustaining effect of the formulation to some extent. But after a certain period, Ludipress did not show any significant effect as the pores made by the xanthan gum network were already blocked. It is found here that when the metformin hydrochloride and the xanthan gum ratio was 1:1, showed a high percentage of drug release, i.e. 91.80% of drug was released after 6 hours. But With a xanthan gum and metformin hydrochloride ratio of 6:1, a very slow release of the drug was obtained. Only 66.68% of the drug was released after 6 hours. The percent loading in this case was 14%. Again, when Ludipress was used in high ratio, it was found to retard the release rate more prominently. Key words: Metformin Hydrochloride, Xanthan Gum, Controlled release capsule Dhaka Univ. J. Pharm. Sci. Vol.4(1) 2005 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website

Dynamics of proton, ion, molecule, and crystal lattice in functional molecular assemblies

2021 ◽  
Author(s):  
Tomoyuki Akutagawa ◽  
Takashi Takeda ◽  
Norihisa Hoshino
Keyword(s):  
Crystal Lattice ◽  
Long Range ◽  
Molecular Assembly ◽  
Molecular Processes ◽  
Molecular Assemblies ◽  
Electrical Conducting ◽  
Molecular Rotations

Dynamic molecular processes, such as short- or long-range proton (H+) and ion (M+) motions, and molecular rotations in electrical conducting and magnetic molecular assembly enable to fabricate the electron –...

Tough hydrogel module towards an implantable remote and controlled release device

2020 ◽  
Vol 8 (3) ◽  
pp. 960-972 ◽  
Author(s):  
Zhi Wei Kenny Low ◽  
Yifei Luo ◽  
Kangyi Zhang ◽  
Qianyu Lin ◽  
Cally Owh ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Controlled Release ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
On Demand ◽  
Release Device

On-demand controllable drug delivery systems enable the administration of precise dosages and thus have the potential to improve overall healthcare.

scholarly journals DESIGN AND IN VITRO CHARACTERIZATION OF FLUTRIMAZOLE MICROSPHERES LOADED TOPICAL EMULGEL

2019 ◽  
pp. 242-251
Author(s):  
MUTHADI RADHIKA REDDY ◽  
SOUMYASTUTIPATNAIK
Keyword(s):  
Controlled Release ◽  
Entrapment Efficiency ◽  
Particle Size Analysis ◽  
Angle Of Repose ◽  
Size Analysis ◽  
Infrared Study ◽  
Topical Gel ◽  
Percentage Yield ◽  
Model Drug

Objective: Flutrimazole is a topical antifungal agent which displays potent broad spectrum in vitro activity against dermatophytes, filamentous fungi, and yeasts. The purpose of the present study is to formulate and evaluate microspheres loaded topical gel containing flutrimazole as model drug microspheres were prepared using aqueous ionotropic gelation method. Methods: Different polymers, the different drug to polymer(s) ratio(s) and other parameters were screened to study their effects on the properties of microspheres and to optimize each parameter. The controlled release emulgel was formulated by changing the polymer ratio. Fourier transform infrared study confirmed the purity of the drug, concede no interaction between the drug and excipients and analyze the parameters affecting the morphology and other characteristics of the resultant products employing scanning electron microscopy. Results: Microspheres loaded topical gel has been shown that encapsulation and controlled release of flutrimazole could reduce the side effect while also reducing percutaneous absorption when administered to the skin. The microspheres obtained were subjected to the preformulation studies such as bulk density, tapped density, angle of repose, Carr’s index, and Hausner’s ratio the results obtained were within the limit. The microspheres were characterized by percentage yield, drug entrapment efficiency, and particle size analysis, then the optimized microspheres formulation were incorporated into the gel prepared with various polymer(s) ratio(s) and were evaluated by parameters such as visual inspection, pH measurement, spreadability studies, viscosity, and in vitro drug release using Franz diffusion cell. Conclusion: The result of studies revealed that the optimized batch shows 97.24% release in 12 h and stable for around there. The microsphere loaded gel has advantages such as efficient absorption and more drug retention time.

Controlled Release of Bone Growth Factors from Injectable, Biodegradable Polymer Scaffolds for Bone Tissue Engineering

2000 ◽  
Vol 662 ◽  
Author(s):  
Elizabeth L. Hedberg ◽  
Antonios G. Mikos
Keyword(s):  
Growth Factors ◽  
Controlled Release ◽  
Bone Growth ◽  
Bone Ingrowth ◽  
Release Kinetics ◽  
Salt Content ◽  
Burst Effect ◽  
Plga Microparticles ◽  
Model Drug

AbstractThe objective of this research is to fabricate injectable, polymeric composites that will act as scaffolds for bone ingrowth as well as carriers for the controlled release of bone growth factors. To that end, the injectable polyester poly(propylene fumarate) (PPF) was loaded with poly(DLlactic-co-glycolic acid) (PLGA) microparticles carrying the model drug FITC-dextran. This preparation was then crosslinked with N-vinyl pyrrolidinone in the presence of benzoyl peroxide as initiator and sodium chloride (NaCl) as leachable porogen. The encapsulation of growth factors in microparticles is necessary to minimize their denaturation during scaffold crosslinking. PLGA microparticles (0.04 g microparticles/g PPF) were incorporated into PPF composites having variable NaCl weight percents (50 and 70 wt% NaCl) and the effect on FITC-dextran release kinetics was determined in vitro for cylinders of diameter 6.5 mm and height 13.0 mm. The FITC-dextran loaded microparticles alone exhibited a large initial burst effect, while the composite materials displayed a smaller burst effect and a longer linear region of release. At day 3, 54.6±2.1%, 5.1±0.9%, and 12.5±0.3% of loaded FITC-dextran was released into pH 7.4 phosphate buffered saline from the microparticles, the 50 wt% NaCl, and the 70 wt% NaCl composites, respectively. By day 28, 90.9±6.9%, 12.7±1.7%, and 34.4±0.4% of loaded FITC-dextran was released. Our results demonstrate that PLGA microparticles can be incorporated into PPF composites and that the release kinetics of FITC-dextran can be systematically manipulated through alteration of the composite initial salt content.

scholarly journals Asparagus cochinchinensisExtract Alleviates Metal Ion-Induced Gut Injury inDrosophila: An In Silico Analysis of Potential Active Constituents

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Weiyu Zhang ◽  
Li Hua Jin
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Morphological Changes ◽  
In Silico Analysis ◽  
Atmospheric Pollutants ◽  
Network Pharmacology ◽  
Active Components ◽  
Copper Zinc ◽  
Asparagus Cochinchinensis ◽  
Epithelial Cell Death

Metal ions and sulfate are components of atmospheric pollutants that have diverse ways of entering the human body. We usedDrosophilaas a model to investigate the effect ofAsparagus cochinchinensis(A. cochinchinensis) extracts on the gut and characterized gut homeostasis following the ingestion of metal ions (copper, zinc, and aluminum). In this study, we found that the aqueousA. cochinchinensisextract increased the survival rate, decreased epithelial cell death, and attenuated metal ion-induced gut morphological changes in flies following chronic exposure to metal ions. In addition, we screened out, by network pharmacology, six natural products (NPs) that could serve as putative active components ofA. cochinchinensisthat prevented gut injury. Altogether, the results of our study provide evidence thatA. cochinchinensismight be an effective phytomedicine for the treatment of metal ion-induced gut injury.

Sign in / Sign up

Export Citation Format

Share Document