pH-Responsive guar gum hydrogels for controlled delivery of dexamethasone to the intestine (original) (raw)
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Gels
The current study reports the fabrication and biological evaluation of hydroxy propyl β-cyclodextrin-g-poly(acrylic acid)/gelatin (HP-β-CD-g-poly(AA)/gelatin) semi-interpenetrating networks (semi-IPN) for colonic delivery of dexamethasone sodium phosphate (DSP). The prepared hydrogels showed pH-dependent swelling and mucoadhesive properties. The mucoadhesive strength of hydrogels increased with an increasing concentration of gelatin. Based on the swelling and mucoadhesive properties, AG-1 was chosen as the optimized formulation (0.33% w/w of gelatin and 16.66% w/w of AA) for further analysis. FTIR revealed the successful development of a polymeric network without any interaction with DSP. SEM images revealed a slightly rough surface after drug loading. Drug distribution at the molecular level was confirmed by XRD. In vitro drug release assay showed pH-dependent release, i.e., a minute amount of DSP was released at a pH of 1.2 while 90.58% was released over 72 h at pH 7.4. The optimi...
Controlled release of dexamethasone from poly(vinyl alcohol) hydrogel
Pharmaceutical Development and Technology, 2019
Controlled release of dexamethasone from poly(vinyl alcohol) hydrogel This study investigated a chemically crosslinked poly (vinyl alcohol) (PVA) hydrogel controlled drug delivery system to deliver the anti-inflammatory drug dexamethasone (DEX). The PVA hydrogels, with different crosslinking densities, were characterised by swelling studies, electron scanning microscopy, viscosity, Fourier transform infrared spectroscopy (FTIR) and in vitro release assessment. Increasing crosslinking density slowed and decreased the swelling and water absorption. FTIR analysis suggested DEX has possible interactions with the crosslinker and the PVA polymer. In vitro release of DEX from PVA hydrogels was sustained for 33 days and appeared to fit the Higuchi and Korsmeyer-Peppas models. This work indicates the likelihood of PVA hydrogel as a controlled drug release system for DEX for anti-inflammatory uses.
Novel Composite pH Controlled Drug Release Hydrogel Containing Dexibuprofen
2018
Objective: The objective of this study was to develop a gelatin-cyclodextrin hydrogel using glutaraldehyde as crosslinker containing Dexibuprofen, characterized by the mucoadhesive and controlled release of drug in the stomach and its in vitro characterization. All non-steroidal anti-inflammatory drugs (NSAID's) cause peptic ulcer in chronic disease condition like rheumatoid arthritis. In conventional dosage form of NSAID's the drug is released at once with reduced duration of action. On other hands in hydrogels dosage form the drug is released slowly with prolongs the duration of action & minimal side effects. This also decreases the dosing frequency. Methods: Nine formulations were developed by varying the gelatin-cyclodextrin (Gel/CD) and glutaraldehyde. Swelling studies of hydrogels were performed at three different pH conditions (1.2, 6.5 and 7.4). The hydrogel samples were also analyzed by Fourier transformed infrared spectroscopy (FTIR), Differential scanning calorime...
Journal of materials science. Materials in medicine, 2002
Hydrogels based on blends of poly(vinyl alcohol) (PVA) with dextran were prepared by a physical cross-linking procedure and used as matrices for the entrapment of biodegradable nanoparticles loaded with dexamethasone. The nanoparticles were prepared, by a solvent evaporation technique, using biodegradable copolymers of poly(lactic acid)-poly(glycolic acid) (PLGA). Size, morphology and surface characteristics of the nanoparticles were evaluated by scanning electron microscopy. The mechanism of drug release from the nanoparticles entrapped into the PVA-based matrices was studied and compared to that from free nanoparticles. The effect of dextran on the in vitro release profile of dexamethasone from the hydrogels was investigated. The obtained results indicate that PLGA nanoparticles are able to release dexamethasone following a diffusion-controlled mechanism. The entrapment of the nanoparticles into the hydrogels affects only slightly this mechanism of drug release. In addition, dextr...
Pharmaceuticals
In this paper, we fabricated semi-interpenetrating polymeric network (semi-IPN) of hydroxypropyl-β-cyclodextrin-grafted-poly(acrylic acid)/poly(vinyl pyrrolidone) (HP-β-CD-g-poly(AA)/PVP) by the free radical polymerization technique, intended for colon specific release of dexamethasone sodium phosphate (DSP). Different proportions of polyvinyl pyrrolidone (PVP), acrylic acid (AA), and hydroxypropyl-beta-cyclodextrin (HP-β-CD) were reacted along with ammonium persulphate (APS) as initiator and methylene-bis-acrylamide (MBA) as crosslinker to develop a hydrogel system with optimum swelling at distal intestinal pH. Initially, all formulations were screened for swelling behavior and AP-8 was chosen as optimum formulation. This formulation was capable of releasing a small amount of drug at acidic pH (1.2), while a maximum amount of drug was released at colonic pH (7.4) by the non-Fickian diffusion mechanism. Fourier transformed infrared spectroscopy (FTIR) revealed successful grafting of...
Hydrogels, the swellable polymeric materials have been used widely as a carrier for drug delivery systems and have gained attention owing to their peculiar characteristics like swelling in aqueous medium, pH or temperature sensitivity or sensitivity towards external stimuli. Hydrogels being biocompatible due to their high water content and low interfacial tension with the biological fluids have been helpful as targetable carriers for bioactive drugs with tissue specificity. The purpose of research is to provide the targeted drug release in the intestine for a prolong period of time. pH sensitive hydrogel, 2-Hydroxyethylmethacrylate-co-acrylamide was prepared by polymerization in aqueous solution from 2-Hydroxyethlmethacrylate(2-HEMA) and acrylamide monomers using N,N-Methylenebis(acrylamide) as a cross linker. It was shown that the swelling behavior of 2-HEMA-co-acrylamide can be controlled by changing the molar concentration of acrylamide. The hydrogel was characterized by FT-IR, SEM, tests to assess swellability, drug loading and dissolution techniques.
Biomacromolecules, 2008
A novel pH-sensitive and biodegradable composite hydrogel, based on a methacrylated and succinic derivative of dextran, named Dex-MA-SA, and a methacrylated and succinic derivative of R,-poly(N-2-hydroxyethyl)-DLaspartamide (PHEA), named PHM-SA, was produced by photocross-linking. The goal was to obtain a colonspecific drug delivery system, exploiting both the pH-sensitive behavior and the colon-specific degradability. The hydrogel prepared with a suitable ratio between the polysaccharide and the polyaminoacid was characterized regarding its swelling behavior in gastrointestinal simulated conditions, chemical and enzymatic degradability, interaction with mucin, and cell compatibility on CaCo-2 cells. Moreover, 2-methoxyestradiol was chosen as a model of anticancer drug and release studies, were performed in the absence or in the presence of dextranase and esterase. The obtained hydrogel, due to its pH-sensitive swelling and enzymatic degradability, together with mucoadhesion and cell compatibility, could be potentially useful as system for the oral treatment of colonic cancer.