Cationic cellulose hydrogels: kinetics of the cross-linking process and characterization as pH-/ion-sensitive drug delivery systems

2003 ◽  
Vol 86 (2-3) ◽  
pp. 253-265 ◽  
Author(s):  
Rosalı́a Rodrı́guez ◽  
Carmen Alvarez-Lorenzo ◽  
Angel Concheiro
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Cross Linking ◽  
The Cross ◽  
Kinetics Of

Biopolymers with Medical Applications Optimized method for obtaining chitosan-based delivery systems

2018 ◽  
Vol 69 (7) ◽  
pp. 1756-1759 ◽  
Author(s):  
Luminita Confederat ◽  
Iuliana Motrescu ◽  
Sandra Constantin ◽  
Florentina Lupascu ◽  
Lenuta Profire
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Average Diameter ◽  
Delivery Systems ◽  
Cross Linking ◽  
Low Molecular Weight ◽  
Polymeric Systems ◽  
Chitosan Microparticles ◽  
Degree Of Swelling

The aim of this study was to optimize the method used for obtaining microparticles based on chitosan � a biocompatible, biodegradable, and nontoxic polymer, and to characterize the developed systems. Chitosan microparticles, as drug delivery systems were obtained by inotropic gelation method using pentasodiumtripolyphosphate (TPP) as cross-linking agent. Chitosan with low molecular weight (CSLMW) in concentration which ranged between 0.5 and 5 %, was used while the concentration of cross-linking agent ranged between 1 and 5%. The characterization of the microparticles in terms of shape, uniformity and adhesion was performed in solution and dried state. The size of the microparticles and the degree of swelling were also determined. The structure and the morphology of the developed polymeric systems were analyzed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM).The average diameter of the chitosan microparticles was around 522 �m. The most stable microparticles were obtained using CSLMW 1% and TPP 2% or CSLMW 0.75%and TPP 1%. The micropaticles were spherical, uniform and without flattening. Using CSLMW in concentration of 0.5 % poorly cross-linked and crushed microparticles have been obtained at all TPP concentrations. By optimization of the method, stable chitosan-based micropaticles were obtained which will be used to develop controlled release systems for drug delivery.

Comparison of chitosan microsphere versus O-carboxymethyl chitosan microsphere for drug delivery systems

2017 ◽  
Vol 32 (5) ◽  
pp. 469-486 ◽  
Author(s):  
Gang Zhou ◽  
Jing Zhang ◽  
Jun Tai ◽  
Qianyi Han ◽  
Lei Wang ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Sustained Release ◽  
Drug Delivery Systems ◽  
Controlled Drug Delivery ◽  
Delivery Systems ◽  
Carboxymethyl Chitosan ◽  
Cross Linking ◽  
Chitosan Microspheres ◽  
Chitosan Microsphere

The development of controlled drug delivery systems for bone regeneration, especially microspheres, has become a research hotspot in recent years. Chitosan and its derivative O-carboxymethyl chitosan have been considered to be an effective way for controlled drug delivery due to their nontoxicity and biodegradability. Currently, most of the studies have researched on synthesizing and characterizing chitosan and O-carboxymethyl chitosan. However, few studies have focused on the differences between chitosan microspheres and O-carboxymethyl chitosan microspheres directly. In this study, chitosan and O-carboxymethyl chitosan microspheres were developed by water-in-oil emulsification cross-linking method using vanillin as the cross-linking agent, and then their physicochemical properties were evaluated by Fourier transform infrared spectroscopy, scanning electron microscopy, and in vitro release testing. The results showed that O-carboxymethyl chitosan was successfully modified by adding carboxymethyl group at the chitosan C6 position.The particle size of chitosan microspheres (50–90 µm) was significantly larger than that of O-carboxymethyl chitosan microspheres (10–50 µm), and the drug release profile of O-carboxymethyl chitosan microspheres showed larger initial burst release within the first day and sustained release at the fourth day, while chitosan microspheres showed sustained release at the seventh day. In addition, Cell Counting Kit-8 assay showed that MC3T3-E1 proliferated well and highly expressed the alkaline phosphatase marker protein on both chitosan and O-carboxymethyl chitosan microspheres. Overall, both chitosan and O-carboxymethyl chitosan microspheres showed good biocompatibility, and chitosan microspheres were superior to O-carboxymethyl chitosan microspheres. Moreover, the different drug release rates suggest that chitosan and O-carboxymethyl chitosan microspheres have the potential to be used for the repair of different bone defects.

scholarly journals Monodispersed sodium hyaluronate microcapsules for transdermal drug delivery systems

2021 ◽  
Author(s):  
Hirotada Hirama ◽  
Yuya Ishikura ◽  
Shinya Kano ◽  
Masanori Hayase ◽  
Harutaka Mekaru
Keyword(s):  
Drug Delivery ◽  
Transdermal Drug Delivery ◽  
Drug Delivery Systems ◽  
Sodium Hyaluronate ◽  
Delivery Systems ◽  
Water Soluble ◽  
Cross Linking ◽  
Transdermal Drug Delivery Systems

This study presents an alternative to cross-linking for the preparation of monodispersed polymer microcapsules made from water-soluble and biocompatible sodium hyaluronate (SH). Water was removed from monodispersed drug-containing SH droplets...

Study on the Preparation of Chitosan/PVA Sustained - Release Microspheres

2011 ◽  
Vol 217-218 ◽  
pp. 71-74
Author(s):  
Jian Xiang Yu ◽  
Qi Song Shi
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Sustained Release ◽  
Drug Delivery Systems ◽  
Drug Loading ◽  
Crosslinking Agent ◽  
Delivery Systems ◽  
Effective Drug ◽  
Cross Linking ◽  
Mass Ratio

Chitosan has prompted the continuous impetus for the development of safe and effective drug delivery systems because of its unique physicochemical and biological characteristics. In this study, PEG-chitosan microspheres loaded with levofloxacin for carrying drugs were prepared by the emulsion cross-linking method. The effect of drug process, the emulsifier, the amount of crosslinking agent, stirring speed, temperature, crosslinking time on the prepare experiment were studied. The effect of the quantity of chitosan and PEG, the mass ratio of chitosan and levofloxacin on the drug loading and release ability were studied in drug release experiments too.

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