scholarly journals Development of Dorzolamide Loaded 6-O-Carboxymethyl Chitosan Nanoparticles for Open Angle Glaucoma

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Ujwala Shinde ◽  
Mohammed Hadi Ahmed ◽  
Kavita Singh
Keyword(s):  
Open Angle Glaucoma ◽  
Maximum Yield ◽  
Chitosan Nanoparticles ◽  
Entrapment Efficiency ◽  
Water Soluble ◽  
Hydroxyl Groups ◽  
Eye Drops ◽  
Ether Linkage ◽  
Ft Ir ◽  
C Nmr

Chitosan (CS) is a biodegradable, biocompatible, and mucoadhesive natural polymer soluble in acidic pH only and can be irritating to the eye. Objective of the study was to synthesize water soluble 6-O-carboxymethyl (OCM-CS) derivative of CS, and to develop CS and OCM-CS nanoparticles (NPs) loaded with dorzolamide hydrochloride (DRZ). CS was reacted with monochloroacetic acid (MCA) for OCM-CS synthesis and was characterized by FT-IR, DSC, and 13C NMR. CS and OCM-CS NPs were prepared by ionic gelation method. Ocular irritation potential were evaluated and therapeutic efficacy was measured by reduction in intraocular pressure (IOP) in normotensive rabbits. Maximum yield was obtained when the ratio of water/isopropyl alcohol was 1/4 at 55°C. The FT-IR, DSC and 13C NMR confirmed the formation of an ether linkage between hydroxyl groups of CS and MCA. The particle size and zeta potential of optimised CSNPs was 250.3 ± 2.62 nm and +33.47 ± 0.723 mV, whereas those for OCM-CSNPs were 187.1 ± 2.72 nm and 30.87 ± 0.86 mV. The entrapment efficiency was significantly improved for OCM-CSNPs, compared to CSNPs. OCM-CSNPs had tailored drug release and improved bioavailability with reduction in pulse entry as compared to CSNPs. Hence, it can be concluded that DRZ loaded OCM-CSNPs would be better alternative option to available eye drops for glaucoma treatment.

scholarly journals Chitosan Nanoparticles as a Percutaneous Drug Delivery System for Hydrocortisone

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Haliza Katas ◽  
Zahid Hussain ◽  
Tay Chai Ling
Keyword(s):  
Particle Size ◽  
Delivery System ◽  
Chitosan Nanoparticles ◽  
Entrapment Efficiency ◽  
Ionic Crosslinking ◽  
Low Molecular Weight Chitosan ◽  
Permeation Studies ◽  
Ft Ir ◽  
Inflammatory Drugs

Hydrocortisone (HC) has formed the mainstay for the management of atopic dermatitis. Hence, HC-loaded chitosan nanoparticles were prepared by ionic crosslinking of high, low molecular weight chitosan (HMwt, LMwt CS) and N-trimethyl chitosan (TMC) with tripolyphosphate. HC loading into CS nanoparticles was confirmed by FT-IR. The particle size of HC-loaded HMwt, LMwt, and TMC nanoparticles was increased from243±12,147±11,and124±9 nm to337±13,222±14,and195±7 nm, respectively, by increasing the pH of CS solution. Their respective zeta potential and entrapment efficiency (EE) were significantly decreased by increasing the pH of CS solution. The swelling ratios of HC loaded HMwt, LMwt, and TMC NPs were increased when the pH of incubating media (PBS) was increased. The same increasing trend was observed in particle size and EE of HC loaded as the CS concentration was increased. The HC loaded CS NPs were generally nonspherical.In-vitropermeation studies showed that HC was efficiently released from the CS NPs in QV cream while in aqueous cream CS NPs provided a sustained release for HC. Thus, it is anticipated that CS NPs are the promising delivery system for anti-inflammatory drugs.

scholarly journals Roles of Novel Reactive Cationic Copolymers of 3-Chloro-2-hydroxypropylmethyldiallylammonium Chloride and Dimethyldiallylammonium Chloride in Fixing Anionic Dyes on Cotton Fabric

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Yikai Yu ◽  
Yuejun Zhang
Keyword(s):  
Ir Spectra ◽  
Cotton Fabric ◽  
Sem Analysis ◽  
Hydroxyl Groups ◽  
Water Color ◽  
Anionic Dyes ◽  
Ether Linkage ◽  
Cotton Sample ◽  
Ft Ir ◽  
Cationic Copolymers

The roles of novel reactive cationic copolymers (P(CMDA-DMDAAC)s) of 3-chloro-2-hydroxypropylmethyldiallylammonium chloride (CMDA) and dimethyldiallylammonium chloride (DMDAAC) in fixing anionic dyes on cotton fabric were studied by modern instrumental analysis technologies such as FT-IR spectra and SEM analysis, to achieve the new theoretical guides for the wide applications of those dye fixatives. The FT-IR spectra of the obtained insoluble-water color lakes verified that they could be formed from the electrostatic interactions of the P(CMDA-DMDAAC)s with anionic dyes, which were further confirmed by the FT-IR analysis of the anionic dyes on dyeing cotton sample fixed by P(CMDA-DMDAAC)s. The FT-IR spectra of cotton samples fixed by P(CMDA-DMDAAC)s showed the absorptions of P(CMDA-DMDAAC)s and the signs similar to the formation of new ether linkage on cotton fabric even after being repeatedly washed, which were further confirmed by the SEM analysis of the fixed dyeing cotton samples. Thus, the reactive units (CMDA) of the obtained P(CMDA-DMDAAC)s could be expected to bring about the covalent bonds with the hydroxyl groups of cotton (cellulose) to form an ether linkage when fixing, resulting in the stronger interactions of P(CMDA-DMDAAC)s with cotton fabric, as well as their electrostatic forces with anionic dyes to produce the insoluble-water color lakes, for the development of fastness of anionic dyes on cotton fabric.

scholarly journals Reaction Mechanism of Etherification of Rice Straw with Epichlorohydrin in Alkaline Medium

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Guanglu Li ◽  
Yan Shang ◽  
Yuhong Wang ◽  
Linshan Wang ◽  
Yuesheng Chao ◽  
...  
Keyword(s):  
Rice Straw ◽  
Alkaline Medium ◽  
Mechanical Performance ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Neutral Sugar ◽  
Dominant Component ◽  
Ft Ir ◽  
Three Stages ◽  
C Nmr

Abstract Wood plastic composites (WPCs) made from plant fibres and plastics have gained more and more attention. Studies have been focused on preparation and mechanical performance of WPCs. While mechanism of chemical modification of cereal straw has rarely been reported. In the present work, rice straw was etherified with epichlorohydrin (EPI) and the mechanism of etherification was investigated. Natural rice straw (NRS) was pretreated with NaOH to move most of hemicellulose and lignin. The alkali treated rice straw (ARS), whose dominant component being cellulose, was etherified with EPI at 120 °C for 1–8 h in toluene with NaOH as catalyst. NRS, ARS and etherified rice straw (ERS) were characterized and analyzed by FT-IR, solid CP/MAS 13C-NMR, elemental analysis and neutral sugar analysis. The etherification reaction was finished within 5 h, and C3H6O units were introduced into the structure of cellulose, leading to the increase of contents of C and H in ERS. The etherification process of ARS in alkaline medium was divided into three stages, during which two hydroxyl groups were replaced by two ether bonds successively, and a new hydroxyl group was formed in the last step. The number of hydroxyl groups in ERS was reduced, and reduction of hydrophilicity of ERS could be expected.

Preparation of Chitosan Nanoparticles for Protein Delivery by w/o/w Emulsion Solvent Evaporation and Simple Ionotropic Gelation Techniques

2007 ◽  
Vol 121-123 ◽  
pp. 751-754 ◽  
Author(s):  
Garnpimol C. Ritthidej ◽  
W. Pichayakorn ◽  
Chulalongkorn Kusonwiriyawong ◽  
V. Lipipun
Keyword(s):  
Protein Delivery ◽  
Drug Loading ◽  
Chitosan Nanoparticles ◽  
In Vitro Release ◽  
Entrapment Efficiency ◽  
Solvent Evaporation ◽  
Water Soluble ◽  
Form Complex ◽  
Ionotropic Gelation

The purpose of this study was to prepare chitosan nanoparticles (CS NP) for controlled protein delivery. Two techniques, simple ionotropic gelation (method [I]) and w/o/w emulsion solvent evaporation containing ionotropic gelation (method [II]), were used to prepare CS NP. Tripolyphosphate (TPP) and Eudragit L100-55 (Eud) were used as anionic agents to form complex with cationic chitosan. Bovine serum albumin (BSA) was encapsulated into NP. The morphological characteristics, particle size and size distribution, protein entrapment efficiency, zeta potential, in vitro release, protein secondary structure and its integrity were investigated. The results showed that CS NP could be prepared by appropriate cationic and anionic ratios in both methods. Excess anionic agents resulted in particle aggregation of micron size. The median sizes of particles were between 0.127-0.273 mcm with method [I] provided the smallest size. The 0.02-0.10% BSA loaded preparations showed the same particle sizes and size distributions as blank preparations. SEM photomicrographs revealed that the obtained NP were spherical. Protein entrapment efficiency was between 47-84% and increased when decreasing the percentage of drug loading. The method [II] with TPP exhibited the highest protein entrapment efficiency, following by the method [II] with Eud and method [I] with TPP, respectively. The zeta potentials were positive. Prolonged in vitro protein release profiles were observed from all preparations of CS NP. After 10 days, the release was between 53-72%. Circular dichroism and SDS-polyaceylamide gel electrophoresis techniques confirmed that these processes did not have any destructive effect on the protein structure. Therefore these preparation techniques could be used to encapsulate water-soluble drugs, proteins, DNA, or antigens into CS NP as effective delivery carriers.

scholarly journals Formulation and In-Vitro Characterization of Chitosan-Nanoparticles Loaded with the Iron Chelator Deferoxamine Mesylate (DFO)

Pharmaceutics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 238 ◽  
Author(s):  
Maria Lazaridou ◽  
Evi Christodoulou ◽  
Maria Nerantzaki ◽  
Margaritis Kostoglou ◽  
Dimitra Lambropoulou ◽  
...  
Keyword(s):  
Sodium Tripolyphosphate ◽  
Drug Loading ◽  
Chitosan Nanoparticles ◽  
Entrapment Efficiency ◽  
Molar Ratio ◽  
Release Mechanism ◽  
Hydroxyl Groups ◽  
Deferoxamine Mesylate ◽  
Pharmacologically Active

The objective of this study was to develop chitosan (CS) nanoparticles (NPs) loaded with deferoxamine mesylate (DFO) for slow release of this iron-chelating drug. Drug nanoencapsulation was performed via ionic gelation of chitosan using sodium tripolyphosphate (TPP) as cross-linker. Nanoparticles with a size ranging between 150 and 400 nm were prepared for neat CS/TPP with a 2/1 molar ratio while their yield was directly dependent on the applied stirring rate during the preparation process. DFO at different content (20, 45 and 75 wt %) was encapsulated into these nanoparticles. We found that drug loading correlates with increasing DFO content while the entrapment efficiency has an opposite behavior due to the high solubility of DFO. Hydrogen-bonding between amino and hydroxyl groups of DFO with reactive groups of CS were detected using FT-IR spectroscopy while X-ray diffraction revealed that DFO was entrapped in amorphous form in the CS nanoparticles. DFO release is directly dependent on the content of loaded drug, while model analysis revealed that the release mechanism of DFO for the CS/TPP nanoparticles is by diffusion. Treatment of murine RAW 264.7 macrophages with nanoencapsulated DFO promoted an increased expression of transferrin receptor 1 (TfR1) mRNA, a typical homeostatic response to iron deficiency. These data provide preliminary evidence for release of pharmacologically active DFO from the chitosan nanoparticles.

Synthesis and Characterization of the Water-Soluble Oleoyl Acetyl Chitosan

2011 ◽  
Vol 284-286 ◽  
pp. 1782-1785
Author(s):  
Wei Chang Ke ◽  
Yi Kun Chen ◽  
Guo Xi Xiong ◽  
Xiang Hong Peng ◽  
Chao Zhu ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Acetic Anhydride ◽  
Chemical Structure ◽  
Water Soluble ◽  
Synthesis And Characterization ◽  
Nmr Spectrum ◽  
Ft Ir ◽  
Oleoyl Chloride ◽  
C Nmr

Oleoyl chloride was synthesized by oleic acid and thionyl dichloride (SOCl2), and then reacted with chitosan in dichloromethane to obtain the oleoyl chitosan. Novel water-soluble oleoyl acetyl chitosan (OACh) was synthesized using oleoyl chloride reacted with acetic anhydride in pyridine. The chemical structure of the OACh was characterized by FT-IR, 1H and 13C NMR. There existed the peaks at 1743.9 cm-1 (C=O) and 1658.1 cm-1(C=C) in FT-IR spectrum, and the peaks at 170.8, 171.6 and 172.5 ppm which were assigned to the C=O of the oleoyl and acetyl groups in 13C NMR spectrum. The results indicated that OACh had oleoyl as hydrophobic moieties and acetyl as hydrophilic moieties.

scholarly journals Investigating The Retention Potential of Chitosan Nanoparticulate Gel: Design, Development, In Vitro & Ex Vivo Characterization

2020 ◽  
Vol 15 (1) ◽  
pp. 41-67
Author(s):  
Shreya Kaul ◽  
Neha Jain ◽  
Jaya Pandey ◽  
Upendra Nagaich
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Ex Vivo ◽  
Chitosan Nanoparticles ◽  
Entrapment Efficiency ◽  
Eye Drops ◽  
Design Development ◽  
In Vitro Drug Release ◽  
Drug Content

Introduction: The main purpose of the research was to develop, optimize and characterize tobramycin sulphate loaded chitosan nanoparticles based gel in order to ameliorate its therapeutic efficacy, precorneal residence time, stability, targeting and to provide controlled release of the drug. Methods: Box-Behnken design was used to optimize formulation by 3-factors (chitosan, STPP and tween 80) and 3-levels. Developed formulation was subjected for characterizations such as shape and surface morphology, zeta potential, particle size, in vitro drug release studies, entrapment efficiency of drug, visual inspection, pH, viscosity, spreadability, drug content, ex vivo transcorneal permeation studies, ocular tolerance test, antimicrobial studies, isotonicity evaluation and histopathology studies. Results: Based on the evaluation parameters, the optimized formulation showed a particle size of 43.85 ± 0.86 nm and entrapment efficiency 91.56% ± 1.04, PDI 0.254. Cumulative in vitro drug release was up to 92.21% ± 1.71 for 12 hours and drug content was found between 95.36% ± 1.25 to 98.8% ± 1.34. TEM analysis unfolded spherical shape of nanoparticles. TS loaded nanoparticulate gel exhibited significantly higher transcorneal permeation as well as bioadhesion when compared with marketed formulation. Ocular tolerance was evaluated by HET-CAM test and formulation was non-irritant and well-tolerated. Histopathology studies revealed that there was no evidence of damage to the normal structure of the goat cornea. As per ICH guidelines, stability studies were conducted and were subjected for 6 months. Conclusion: Results revealed that the developed formulation could be an ideal substitute for conventional eye drops for the treatment of bacterial keratitis.

Solubility Enhancement of Poorly Water-Soluble Antifungal Drug Acyclovir by Nanocrystal Formulation Approach

2018 ◽  
Vol 11 (2) ◽  
pp. 4036-4042
Author(s):  
Prakash Goudanavar ◽  
Ankit Acharya ◽  
Vinay C.H
Keyword(s):  
Chemical Interaction ◽  
Research Work ◽  
Antiviral Drug ◽  
In Vitro Release ◽  
Oral Route ◽  
Water Soluble ◽  
Precipitation Method ◽  
Dsc Studies ◽  
Ft Ir

Administration of an antiviral drug, acyclovir via the oral route leads to low and variable bioavailability (15-30%). Therefore, this research work was aimed to enhance bioavailability of acyclovir by nanocrystallization technique. The drug nanocrystals were prepared by anti-solvent precipitation method in which different stabilizers were used. The formed nanocrystals are subjected to biopharmaceutical characterization including solubility, particle size and in-vitro release. SEM studies showed nano-crystals were crystalline nature with sharp peaks. The formulated drug nanocrystals were found to be in the range of 600-900nm and formulations NC7 and NC8 showed marked improvement in dissolution velocity when compared to pure drug, thus providing greater bioavailability. FT-IR and DSC studies revealed the absence of any chemical interaction between drug and polymers used. 

Recent Advances in Novasome Formulation Technology

2014 ◽  
Vol 7 (2) ◽  
pp. 2407-2411
Author(s):  
J M Shah ◽  
N.H Shah ◽  
Hadiya P D
Keyword(s):  
Drug Delivery ◽  
Effective Means ◽  
Entrapment Efficiency ◽  
Bilayer Membrane ◽  
Water Soluble ◽  
Delivery Methods ◽  
Liposomal Drug ◽  
Pharmaceutical Technology ◽  
Insoluble Drugs ◽  
Novel Drug

Pharmaceutical technology has developed various newer modes of novel drug delivery aspects. Modifications in the previously existing drug delivery methods have led to various newly innovated technologies serving as a safe and effective means of improvement over the existing ones. Novasome technology is one of the new innovations of liposomes which have solved many of the problems related to liposomal drug delivery system. It offers a seven bilayer membrane which has the ability to incorporate both water soluble and insoluble drugs. It has an excellent entrapment efficiency which provides better medication. Formulation of novasomes is achieved in a high shear device. Due to its numerous advantages, novasomes have been used extensively in various fields like cosmetics, chemical, personal care, foods, pharmaceuticals and agrochemicals.

Synthesis and Evaluation of Levulinic Ester as Biodiesel Additives

2020 ◽  
Vol 71 (8) ◽  
pp. 21-26
Author(s):  
Elena-Emilia Oprescu ◽  
Cristina-Emanuela Enascuta ◽  
Elena Radu ◽  
Vasile Lavric
Keyword(s):  
Maximum Yield ◽  
Strength Distribution ◽  
Point Of View ◽  
Reaction Parameters ◽  
X Ray ◽  
Ethyl Levulinate ◽  
Ft Ir ◽  
Ir Analysis ◽  
Biodiesel Blend ◽  
Acid Strength Distribution

In this study, the SO42-/TiO2-La2O3-Fe2O3 catalyst was prepared and tested in the conversion of fructose to ethyl levulinate . The catalyst was characterized from the point of view of the textural analysis, FT-IR analysis, acid strength distribution, X-ray powder diffraction and pyridine adsorption IR spectra. The influence of the reaction parameters on the ethyl levulinate yield was study. The maximum yield of 37.95% in levulinate esters was obtained at 180 �C, 2 g catalyst and 4 h reaction time. The effect of ethyl levulinate addition to diesel-biodiesel blend in different rates, i.e, 0.5, 1, 2.5, 5 (w.t %) on density, kinematic viscosity and flash point was evaluated and compared with the European specification.

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