Development and In Vitro Evaluation of High Molecular Weight Chitosan Based Polymeric Composites for Controlled Delivery of Valsartan

2016 ◽  
Vol 35 (4) ◽  
pp. 361-368 ◽  
Author(s):  
MUHAMMAD SOHAIL ◽  
MAHMOOD AHMAD ◽  
MUHAMMAD USMAN MINHAS ◽  
HAROON RASHID ◽  
IKRIMA KHALID
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Polymeric Composites ◽  
Controlled Delivery ◽  
In Vitro Evaluation ◽  
High Molecular Weight Chitosan

scholarly journals Physicochemical and Antifungal Properties of Clotrimazole in Combination with High-Molecular Weight Chitosan as a Multifunctional Excipient

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 591
Author(s):  
Bożena Grimling ◽  
Bożena Karolewicz ◽  
Urszula Nawrot ◽  
Katarzyna Włodarczyk ◽  
Agata Górniak
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Weight Ratio ◽  
Scanning Calorimetry ◽  
Minimal Inhibitory Concentrations ◽  
Dissolution Tests ◽  
Effective Combination ◽  
The Impact ◽  
High Molecular Weight Chitosan

Chitosans represent a group of multifunctional drug excipients. Here, we aimed to estimate the impact of high-molecular weight chitosan on the physicochemical properties of clotrimazole–chitosan solid mixtures (CL–CH), prepared by grinding and kneading methods. We characterised these formulas by infrared spectroscopy, differential scanning calorimetry, and powder X-ray diffractometry, and performed in vitro clotrimazole dissolution tests. Additionally, we examined the antifungal activity of clotrimazole–chitosan mixtures against clinical Candida isolates under neutral and acid conditions. The synergistic effect of clotrimazole and chitosan S combinations was observed in tests carried out at pH 4 on Candida glabrata strains. The inhibition of C. glabrata growth reached at least 90%, regardless of the drug/excipient weight ratio, and even at half of the minimal inhibitory concentrations of clotrimazole. Our results demonstrate that clotrimazole and high-molecular weight chitosan could be an effective combination in a topical antifungal formulation, as chitosan acts synergistically with clotrimazole against non-albicans candida strains.

scholarly journals Activity of Chitosan and Its Derivatives against Leishmania major and Leishmania mexicana In Vitro

2019 ◽  
Vol 64 (3) ◽  
Author(s):  
Alaa Riezk ◽  
John G. Raynes ◽  
Vanessa Yardley ◽  
Sudaxshina Murdan ◽  
Simon L. Croft
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Leishmania Major ◽  
Oxygen Species ◽  
Leishmania Mexicana ◽  
Content Type ◽  
High Molecular Weight Chitosan

ABSTRACT There is an urgent need for safe, efficacious, affordable, and field-adapted drugs for the treatment of cutaneous leishmaniasis, which newly affects around 1.5 million people worldwide annually. Chitosan, a biodegradable cationic polysaccharide, has previously been reported to have antimicrobial, antileishmanial, and immunostimulatory activities. We investigated the in vitro activity of chitosan and several of its derivatives and showed that the pH of the culture medium plays a critical role in antileishmanial activity of chitosan against both extracellular promastigotes and intracellular amastigotes of Leishmania major and Leishmania mexicana. Chitosan and its derivatives were approximately 7 to 20 times more active at pH 6.5 than at pH 7.5, with high-molecular-weight chitosan being the most potent. High-molecular-weight chitosan stimulated the production of nitric oxide and reactive oxygen species by uninfected and Leishmania-infected macrophages in a time- and dose-dependent manner at pH 6.5. Despite the in vitro activation of bone marrow macrophages by chitosan to produce nitric oxide and reactive oxygen species, we showed that the antileishmanial activity of chitosan was not mediated by these metabolites. Finally, we showed that rhodamine-labeled chitosan is taken up by pinocytosis and accumulates in the parasitophorous vacuole of Leishmania-infected macrophages.

scholarly journals Synthesis and Characterization of High Molecular Weight Chitosan, and Antioxidant Activity of Its Chitosan Oligosaccharide Encapsulation

2021 ◽  
Vol 42 (1) ◽  
pp. 29-38
Author(s):  
Hari Sharan Adhikari ◽  
Aditya Garai ◽  
Bishnu Prasad Marasini ◽  
Rameshwar Adhikari ◽  
Paras Nath Yadav
Keyword(s):  
Molecular Weight ◽  
Antioxidant Activity ◽  
High Molecular Weight ◽  
Synthesis And Characterization ◽  
Target Cells ◽  
Chitosan Oligosaccharide ◽  
High Molecular Weight Chitosan ◽  
In Vitro Antioxidant Activity

High molecular weight nanocrystalline chitosan (HMWNC)with Mw of 350 kDa and 66.92% DDA was prepared by alkaline N-deacetylation of chitin that was abundantly obtained after demineralization and deproteinization of pulverized crab shells, and commercially available chitosan oligosaccharide (COS) with average Mw< 3000 Da and 87% DDA was encapsulated with HMWNC. The encapsulation of COS as a pharmaceutical ingredient into HMWC was hypothesized to enhance the bioavailability of COS in target cells. The HMWNC encapsulated chitosan oligosaccharide (COS-HMWNC) showed in vitro antioxidant activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals (IC50 = 512.6±14.4 μg/mL) while others showed less than 50% inhibition at 1000 μg/mL. The lower the molecular weight of chitosan, the higher was the antioxidant activity. The study showed that the encapsulation of COS molecules in HMWNCcould be used as a simple and effective way of enhancing the antioxidant activity of COS.

scholarly journals In vitro evaluation of antiviral and virucidal activity of a high molecular weight hyaluronic acid

2011 ◽  
Vol 8 (1) ◽  
pp. 141 ◽  
Author(s):  
Claudio Cermelli ◽  
Alessandro Cuoghi ◽  
Monica Scuri ◽  
Clotilde Bettua ◽  
Rachele G Neglia ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Hyaluronic Acid ◽  
High Molecular Weight ◽  
Virucidal Activity ◽  
In Vitro Evaluation

The Effect of Dextran of Various Molecular Weight on the Coagulation in Dogs

1961 ◽  
Vol 06 (01) ◽  
pp. 015-024 ◽  
Author(s):  
Sven Erik Bergentz ◽  
Oddvar Eiken ◽  
Inga Marie Nilsson
Keyword(s):  
Molecular Weight ◽  
Body Weight ◽  
High Molecular Weight ◽  
Bleeding Time ◽  
Factor Vii ◽  
Low Molecular Weight ◽  
Factor V ◽  
Coagulation Mechanism ◽  
Coagulation Defects

Summary1. Infusions of low molecular weight dextran (Mw = 42 000) to dogs in doses of 1—1.5 g per kg body weight did not produce any significant changes in the coagulation mechanism.2. Infusions of high molecular weight dextran (Mw = 1 000 000) to dogs in doses of 1—1.5 g per kg body weight produced severe defects in the coagulation mechanism, namely prolongation of bleeding time and coagulation time, thrombocytopenia, pathological prothrombin consumption, decrease of fibrinogen, prothrombin and factor VII, factor V and AHG.3. Heparin treatment of the dogs was found to prevent the decrease of fibrinogen, prothrombin and factor VII, and factor V otherwise occurring after injection of high molecular weight dextran. Thrombocytopenia was not prevented.4. In in vitro experiments an interaction between fibrinogen and dextran of high and low molecular weight was found to take place in systems comprising pure fibrinogen. No such interaction occurred in the presence of plasma.5. It is concluded that the coagulation defects induced by infusions of high molecular weight dextran are due to intravascular coagulation.

scholarly journals Identity and Origin of the ATPase activity associated with neuronal microtubules. I. The ATPase activity is associated with membrane vesicles.

1983 ◽  
Vol 96 (5) ◽  
pp. 1298-1305 ◽  
Author(s):  
D B Murphy ◽  
R R Hiebsch ◽  
K T Wallis
Keyword(s):  
Molecular Weight ◽  
Atpase Activity ◽  
High Molecular Weight ◽  
Brain Tissue ◽  
Membrane Vesicles ◽  
Microtubule Associated Proteins ◽  
In Vitro Assembly ◽  
Microtubule Protein ◽  
Associated Proteins

Microtubule protein purified from brain tissue by cycles of in vitro assembly-disassembly contains ATPase activity that has been postulated to be associated with microtubule-associated proteins (MAPs) and therefore significant for studies of microtubule-dependent motility. In this paper we demonstrate that greater than 90% of the ATPase activity is particulate in nature and may be derived from contaminating membrane vesicles. We also show that the MAPs (MAP-1, MAP-2, and tau factors) and other high molecular weight polypeptides do not contain significant amounts of ATPase activity. These findings do not support the concept of "brain dynein" or of MAPs with ATPase activity.

Interaction of Streptococcus mutans Glucosyltransferases with Teichoic Acids

1980 ◽  
Vol 29 (2) ◽  
pp. 376-382
Author(s):  
H. K. Kuramitsu ◽  
L. Wondrack ◽  
M. McGuinness
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Streptococcus Mutans ◽  
Teichoic Acid ◽  
Lipoteichoic Acid ◽  
Water Soluble ◽  
Heat Inactivation ◽  
Teichoic Acids ◽  
Insoluble Glucan

The Streptococcus mutans GS5 glucosyltransferase activities (both water-soluble and -insoluble glucan-synthesizing fractions) were inhibited by purified lipoteichoic acid. In vitro sucrose-dependent colonization of smooth surfaces by strain GS5 was also markedly reduced in the presence of the amphipathic molecules. The inhibition of soluble glucan synthesis by lipoteichoic acid appeared to be competitive with respect to both sucrose and primer dextran T10. These inhibitory effects were dependent on the presence of the fatty acid components of lipoteichoic acid since deacylated lipoteichoic acids did not inhibit glucosyltransferase activity. However, the deacylated molecules did interact with the enzymes since deacylated lipoteichoic acid partially protected the enzyme activity against heat inactivation and also induced the formation of high-molecular-weight enzyme complexes from the soluble glucan-synthesizing fraction. The presence of teichoic acid in high-molecular-weight aggregates of glucosyltransferase isolated from the culture fluids of strain GS5 was suggested by the detection of polyglycerophosphate in these fractions. In addition to strain GS5, two other organisms containing polyglycerophosphate teichoic acids, Lactobacillus casei and Lactobacillus fermentum , were demonstrated to bind glucosyltransferase activity. These results are discussed relative to the potential role of teichoic acid-glucosyltransferase interactions in enzyme binding to the cell surface of S. mutans and the formation of high-molecular-weight enzyme aggregates in the culture fluids of the organism.

Preparation of high-molecular weight and high-sulfate content chitosans and their potential antioxidant activity in vitro

2005 ◽  
Vol 61 (2) ◽  
pp. 148-154 ◽  
Author(s):  
Ronge Xing ◽  
Song Liu ◽  
Huahua Yu ◽  
Zhanyong Guo ◽  
Zhien Li ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Antioxidant Activity ◽  
High Molecular Weight ◽  
Sulfate Content ◽  
High Sulfate
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