pH-Sensitive Swelling and Drug-Release Properties of Chitosan—Poly(ethylene oxide) Semi-interpenetrating Polymer Network

Patel, Vijay R.; Amiji, Mansoor M.

doi:10.1021/bk-1996-0627.ch017

Cited by 14 publications

(17 citation statements)

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“…At a dose of 50 mg/kg administered to rats, chitosan was able to prevent ethanol-induced gastric ulcer formation (Ito et al 2000). Although chitosan has unusual susceptibility for degradation by many enzymes (Yalpani and Pantaleone 1994), we have found that the polymer does not degrade with pepsin or pancreatin (Patel and Amiji 1996c). Higher molecular weight chitosan (i.e., >500,000 daltons), therefore, will probably be excreted from the body unchanged or as a bile/fatty acid-complex after oral administration.…”

Section: Chitosan As a Bioadhesive Polymermentioning

confidence: 78%

Tetracycline-containing Chitosan Microspheres for Local Treatment of Helicobacter pylori Infection

Amiji

2006

Cellulose

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Helicobacter pylori infection is currently known to be the cause of at least 75% of all peptic ulcers. Although triple therapy protocols used at present in the clinics have resulted in significant benefits to the patients, the ultimate 100% eradication efficiency has never been achieved. In addition, the development of multidrug resistance to standard anti-microbial therapy can seriously hinder effective management of the disease. A rational approach to treat H. pylori, which localizes predominantly in the antral region of the stomach, is necessary for complete eradication of the infection. In this article, I review the summary of our work over the last several years on development of stomach-specific anti-H. pylori therapy using bioadhesive chitosan microspheres. To determine the gastric residence and local tetracycline concentrations as a function of time, tetracycline-containing chitosan microspheres were formulated and evaluated using the fasted Mongolian gerbil model. The H. pylori-infected gerbil model was used to evaluate the efficacy of the tetracyclinecontaining chitosan microsphere formulation. These preliminary results show great promise for this delivery strategy in the treatment of localized gastro-intestinal tract infections. Drug carrier systems can be engineered with the appropriate therapeutic agent(s) for efficient delivery to the target site and provide better control over localized infectious diseases. This strategy will ultimately lead to favorable clinical outcomes with less potential for resistance development.

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Section: Chitosan As a Bioadhesive Polymermentioning

confidence: 78%

Tetracycline-containing Chitosan Microspheres for Local Treatment of Helicobacter pylori Infection

Amiji

2006

Cellulose

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“…Simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) was primed in accordance with the United States Pharmacopoeia [ 40 ]. The SGF and SIF medium was prepared with pH 1.2 and pH 6.8, respectively.…”

Section: Resultsmentioning

confidence: 99%

Mitigated Oxidative Stress and Cognitive Impairments in Transient Global Ischemia using Niosomal Selegiline-NBP delivery

Jafari

Gharbavi

Baghdadchi

et al. 2022

Behavioural Neurology

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Stroke is the most common reason for adult disabilities and the second ground for death worldwide. Our previous study revealed that selegiline serves as an alternative candidate in transient hypoxia-ischemia. However, aggressive and restless behavior was observed in stroke-induced rats receiving 4 mg/kg selegiline. In comparison, 1 mg/kg selegiline could induce negligible therapeutic effects on mitochondrial dysfunction and histopathological changes. Therefore, we designed oral noisome-based selegiline attached to 4-(4-nitrobenzyl) pyridine to improve transient global ischemia by attenuating cognitive impairments, oxidative stress, and histopathological injury. The investigation was performed in transient hypoxia-ischemia-induced rats by oral administration of nanoformulation containing selegiline (0.25-1 mg/kg) for 4 weeks (3 times a week). Novel object recognition (NOR) was considered to evaluate their cognitive dysfunction. Oxidative stress parameters and brain histopathological assessments were determined following the scarification of rats. Outstandingly, our data demonstrated slower selegiline release from niosomes relative to free drug, which was also in a controlled manner. Our data confirmed significant improvement in cognitive behavior in the NOR test, an increase in glutathione level and total antioxidant power, a decline in MDA and protein carbonyl level, as well as a decreased number of dead cells in histopathological assessment after being exposed to (0.5-1 mg/kg) selegiline-NBP nanoformulation. These data manifested that the selegiline-NBP nanoformulation (0.5-1 mg/kg) could significantly reduce oxidative damage, cognitive dysfunction, and histopathological damage compared to transient hypoxia-ischemia rats, which is 20 times lower than the therapeutic dose in humans. Therefore, the proposed nanoformulation would be capable as an alternative candidate without side effects in stroke.

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“…The dried samples were placed in a closed system above a saturated K 2 CrO 4 salt solution for swelling until moisture equilibrium was reached. 31 The Swelling ratio, Q , 30,32 was calculated using sample dry weight, W d , and the weight of the swollen sample, W s , in the equation …”

Section: Response To Moisturementioning

confidence: 99%

“…In vitro release studies of riboflavin in SGF were reported with release profiles of riboflavin entrapped in calcium alginate and polyglycidyl methacrylate sodium alginate-grafted hydrogels. 29 Patel and Amiji 30 investigated the release of riboflavin in SGF from chitosan-polyethylene oxide (PEO) hydrogel for in vitro site-specific delivery to the stomach and reported the swelling ratio (weight of the swollen hydrogel/weight of the dry hydrogel) and release kinetics by applying the Korsmeyer–Peppas model, M t / M ∞ = k . t n .…”

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confidence: 99%

Keratin sponge/hydrogel II: Active agent delivery

Cardamone¹

2013

Textile Research Journal

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Keratin sponge/hydrogels, described in Part I as the products of oxidation and reduction hydrolysis of fine and coarse wool fibers, were examined as excipient-platforms for the delivery of riboflavin. By absorption through well-defined pores and networks, saturated moisture equilibrium was reached within one hour with swelling ratios of 3.7-5.7. Riboflavin uptake by the four different keratin sponge/hydrogels was from 27.9 to 224 mg. Within 60 minutes, reductive keratin sponge/hydrogels from fine and coarse wool, and the oxidative species from fine wool, released 100% riboflavin at 1.58-1.73% per minute and oxidative sponge/hydrogel from coarse wool released 48% riboflavin at 0.8% riboflavin per minute. Rates of riboflavin release were faster within the initial 10 minutes where reductive sponge/hydrogels released 80-84% riboflavin at 8.0-8.4% per minute and oxidative sponge/hydrogels released 26-63% riboflavin at 2.6-6.3% per minute. Riboflavin delivery at timed intervals was examined with the Korsmeyer-Peppas mathematical model for fractional release. Release patterns followed quasi-Fickian diffusion of the drug by transport through channels and voids. All keratin sponge/hydrogels functioned as site-specific agents with two-stage delivery where immediate release of riboflavin was followed by a period of prolonged, lower dosage release. Swelling studies, the mobility of water, and the behavior of riboflavin release favorably framed keratin sponge/hydrogels as microfluidic devices with implied applications for advanced biomedical and biotechnological applications.Keywords keratin, sponge/hydrogel, riboflavin delivery/ diffusion drug release Hydrogel biopolymers -insoluble, three-dimensional, and hydrophilic -are capable of absorbing and releasing large amounts of fluids while maintaining structural integrity through internal physical and molecular associations, crosslinking, and crystallite entanglements. Applications include contact lenses, biosensor membranes, artificial heart liners, artificial skin material, cell cultivation, and drug delivery devices. 1 Sponge/ hydrogels of keratin protein provide super-molecular, dense aggregates in a porous matrix. These materials functioned as biocompatible orthopedic supports to restore form and function. 2 Implanted keratin was biocompatible and useful for cell tissue and scaffolds for fibroblasts as anti-thrombogenic biomaterial. [3][4][5] Keratin gels, mats, scaffolds, and films are of significant interest for biotechnological and biomedical applications. 6-14 Keratin functional platforms adhere naturally to keratinous substrates, such as hair, skin, and nails, and can deliver beneficial agents for health, medicine, and personal care. As a solid matrix, keratin sponge/ hydrogel can be examined for implantation where silicone-derived materials are typically used. [14][15][16][17][18][19][20][21][22][23] In Part I keratin protein was isolated from the hydrolysis of wool fiber and formed into sponge/hydrogels. These materials were examined as ionic platforms with properti...

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pH-Sensitive Swelling and Drug-Release Properties of Chitosan—Poly(ethylene oxide) Semi-interpenetrating Polymer Network

Cited by 14 publications

References 0 publications

Tetracycline-containing Chitosan Microspheres for Local Treatment of Helicobacter pylori Infection

Tetracycline-containing Chitosan Microspheres for Local Treatment of Helicobacter pylori Infection

Mitigated Oxidative Stress and Cognitive Impairments in Transient Global Ischemia using Niosomal Selegiline-NBP delivery

Keratin sponge/hydrogel II: Active agent delivery

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