pH-sensitive hydrogel containing acetaminophen silyl ethers for colon-specific drug delivery

Mahkam, Mehrdad; Assadi, M. G.; Golipour, N.

doi:10.1163/156855506778944019

Cited by 13 publications

(10 citation statements)

References 10 publications

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“…The swelling properties of the ionic hydrogels are unique due to the ionization of their pendent functional groups. 32 Swelling Ratio. To measure the swelling, preweighed dry drug-free hydrogels were immersed in various buffer solutions (pH 7.4 and pH 1) at 37 o C. After excess water on the surface was removed with the filter paper, the weight of the swollen samples was measured at various time intervals.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and characterization of novel ph-sensitive hydrogels containing ibuprofen pendents for colon-specific drug delivery

2009

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The aim of this study was to develop novel intestinal specific drug delivery systems with pH sensitive swelling and drug release properties. The carboxyl group of ibuprofen was converted to a vinyl ester group by reacting ibuprofen and vinyl acetate as an acylating agent in the presence of catalyst. The glucose-6-acrylate-1, 2, 3, 4-tetraacetate (GATA) monomer was prepared under mild conditions. Cubane-1, 4-dicarboxylic acid (CDA) linked to two 2-hydroxyethyl methacrylate (HEMA) group was used as the crosslinking agent (CA). Methacrylic-type polymeric prodrugs were synthesized by the free radical copolymerization of methacrylic acid, vinyl ester derivative of ibuprofen (VIP) and GATA in the presence of cubane crosslinking agent. The structure of VIP was characterized and confirmed by FTIR, 1 H NMR and 1 3 C NMR spectroscopy. The composition of the cross-linked three-dimensional polymers was determined by FTIR spectroscopy. The hydrolysis of drug polymer conjugates was carried out in cellophane membrane dialysis bags, and the in vitro release profiles were established separately in enzyme-free simulated gastric and intestinal fluids (SGF, pH 1 and SIF, pH 7.4). The detection of a hydrolysis solution by UV spectroscopy at selected intervals showed that the drug can be released by hydrolysis of the ester bond between the drug and polymer backbone at a low rate. Drug release studies showed that increasing the MAA content in the copolymer enhances the rate of hydrolysis in SIF. These results suggest that these polymeric prodrugs can be useful for the release of ibuprofen in controlled release systems.

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Section: Resultsmentioning

confidence: 99%

Synthesis and characterization of novel ph-sensitive hydrogels containing ibuprofen pendents for colon-specific drug delivery

2009

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“…Attaching the organosilyl groups to macromolecular chains should lead to important modifications of polymer properties such as biocompatibility. Silicones, or silicon polymers, have a number of advantages for use in medical devices and drug-delivery systems [15,16]. Silicone's hydrophobicity makes it particularly suitable for the delivery of lipophilic drugs [17,18].…”

Section: Resultsmentioning

confidence: 99%

Novel Carriers for Oral Delivery of Hydrophobic Drugs

Mahkam

2009

Designed Monomers and Polymers

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For the first time, the glucose-6-acrylate-1,2,3,4-tetraacetate (GATA) monomer was prepared under mild conditions. The removal of protecting acetate groups from GATA was carried out before the silylation and then Me 3 Si was covalently linked with glucose acrylate (GA). Cubane-1,4-dicarboxylic acid (CDA) was covalently linked with 2-hydroxyethyl methacrylate (HEMA). The silyl-linked GA is abbreviated as TMSiGA. CDA linked to two HEMA groups was used as the cross-linking agent (CA). Free radical crosslinking co-polymerization of the methacrylic acid (MAA) and hydrophobic glycomonomer (TMSiGA) with two different molar ratios of CA was carried out at 60-70 • C. The compositions of the cross-linked threedimensional polymers were determined by FT-IR spectroscopy. A model hydrophobic drug, the steroid hormone estradiol, was entrapped in these gels and the in vitro release profiles were carried out in enzymefree simulated gastric and intestinal fluids (SGF and SIF, respectively). To overcome the hydrophobicity of estradiol, the buffers for estradiol were modified by adding ethanol. The influence of the structures and amounts of silane monomers on the swelling and drug-release behaviors were studied.

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“…4-Chloromethylstyrene (CMS), also called 4-vinylbenzylchloride (VBC), is a monomer that can be reacted with a series of reagent to produce polymer with functional groups [14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of ionic liquid functionalized polymers for drug delivery of an anti-inflammatory drug

Hosseinzadeh

Mahkam

Galehassadi

2012

Designed Monomers and Polymers

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Polymeric forms of ionic liquids have many potential applications because of their ionic nature. Two ionic liquid monomers, 1-(4-vinylbenzyl)-3-methyl imidazolium hexafluorophosphate (VMIH) and 1-(4-vinylbenzyl)-4-(dimethylamino)-pyridinium hexafluorophosphate (VDPH), were synthesized through the quaternization of N-methylimidazole and 4-(dimethylamino) pyridine with 4-vinylbenzylchloride, respectively, and a subsequent anion exchange reaction with potassium hexafluorophosphate. The homopolymers of VMIH, VDPH, and its copolymers with methyl styrene (in various mole ratios) were synthesized by free radical polymerizations at 70°C using α,α′-azobis(isobutyronitrile) as an initiator. Anionic drug molecule, naproxen (an anti-inflammatory drug), was effectively loaded into these positive charges polymers (PCP) and remained inside of the PCP under acidic environment (pH 2-6.5). The amount of loading of drug was increased with increasing positive charge densities resulting from the increasing number of ionic liquids groups. PCP as a controllable release of anionic drug molecules can be used as an oral delivery drug systems targeting at intestine. This drug can be remained trapped in the polymers when passing through the acidic and neutral environment and be released in intestine, where the environmental pH is close to basic.

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pH-sensitive hydrogel containing acetaminophen silyl ethers for colon-specific drug delivery

Cited by 13 publications

References 10 publications

Synthesis and characterization of novel ph-sensitive hydrogels containing ibuprofen pendents for colon-specific drug delivery

Synthesis and characterization of novel ph-sensitive hydrogels containing ibuprofen pendents for colon-specific drug delivery

Novel Carriers for Oral Delivery of Hydrophobic Drugs

Synthesis and characterization of ionic liquid functionalized polymers for drug delivery of an anti-inflammatory drug

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