نتایج جستجو برای: methacrylic acid copolymer

تعداد نتایج: 756753  

Journal: :jundishapur journal of natural pharmaceutical products 0
abbas akhgari nanotechnology research center and school of pharmacy, ahvaz jundishapur university of medical sciences, tel./fax: +98-6113738381, ir iran mohammadreza abbaspour nanotechnology research center and school of pharmacy, ahvaz jundishapur university of medical sciences, tel./fax: +98-6113738381, ir iran ; nanotechnology research center and school of pharmacy, ahvaz jundishapur university of medical sciences, tel./fax: +98-6113738381, ir iran meysam moradkhanizadeh nanotechnology research center and school of pharmacy, ahvaz jundishapur university of medical sciences, tel./fax: +98-6113738381, ir iran

conclusions it was shown that combination of pectin and eudragits can relatively control drug release in the upper gi. on the other hand, pectin degraded in the presence of pectinase and formulations were susceptible to the colonic media. results it was shown that in the presence of pectin, formulations without erl had a relative resistance to drug release in sgf. pellets containing pectin and ...

1997
Anthony M. Lowman Nikolaos A. Peppas

Graft copolymer networks of poly(methacrylic acid-g-ethylene glycol) exhibiting pHdependent swelling behavior due to the formation of interpolymer complexes were prepared by free radical solution polymerization of methacrylic acid and poly(ethylene glycol) monomethacrylate. Dynamic swelling studies established the swelling/deswelling process due to hydrogen bonding. Additionally, the effects of...

2006
Yasuyuki Takao Nobukazu Miyagawa Shigeru Takahara Tsuguo Yamaoka

The cyclized copolymerization of methacrylic anhydride with N phenyldimethacrylamide and methacrylonitrile was carried out. The polymer consists of six-membered cyclic acid anhydride and five-membered imide ring. The cyclic acid anhydride was hydrolyzed by generated acid catalyst from photo-acid generator (PAG). The hydrolyzed copolymer is dissolved in an alkaline solution. We applied this copo...

Journal: :Chemical communications 2011
Jana Juan-Alcañiz Maarten Goesten Alberto Martinez-Joaristi Eli Stavitski Andrei V Petukhov Jorge Gascon Freek Kapteijn

The templating effect of the Keggin polyanion derived from phosphotungstic acid (PTA) during the synthesis of NH(2)-MIL-101(Al) has been investigated by means of in situ SAXS/WAXS. Kinetic analysis and structural observations demonstrate that PTA acts as a nucleation site and that it stabilizes the precursor phase NH(2)-MOF-235(Al). Surprisingly kinetics of formation are little changed.

1999
A. M. Lowman N. A. Peppas

Interpolymer complexation is associated with the formation of hydrogen bonds between pendent and/or grafted groups of a single polymer or copolymers. The degree of complexation can be described theoretically in terms of complexation/decomplexation equilibrium characteristics. Graft copolymer networks of poly(methacrylic acid-g-ethylene glycol) were prepared by free radical solution polymerizati...

1990
Nikolaos A. Peppas John Klier

Graft copolymers of poly (ethylene glycol) with poly (methacrylic acid) were prepared by reaction of poly (ethylene glycol) methacrylate macromonomer with methacrylic acid in the presence of tetraethylene glycol dimethacrylate as a crosslinking agent. The materials were swollen in aqueous solutions with the pH ranging from 1.5 to 12.0. Dynamic swelling studies were performed. The swelling rates...

Journal: :Acta pharmaceutica 2007
Tahar Bartil Mahmoud Bounekhel Calberg Cedric Robert Jeerome

The purpose of this study is to develop novel intestinal-specific drug delivery systems with pH sensitive swelling and drug release properties. Methacrylic-type polymeric prodrugs were synthesized by free radical copolymerization of methacrylic acid, poly(ethyleneglycol monomethyl ether methacrylate) and a methacrylic derivative of N-(4-hydroxyphenyl)-2-(4-methoxyphenyl) acetamide in the presen...

Journal: :Chemical & pharmaceutical bulletin 2003
Toshihiro Shimizu Yoshinori Nakano Shuji Morimoto Tetsuro Tabata Naoru Hamaguchi Yasutaka Igari

Lansoprazole fast-disintegrating tablet (LFDT) is a new patient-friendly formulation of lansoprazole. Since lansoprazole is an antiulcer agent and is unstable under acidic conditions, we have developed LFDT as an orally disintegrating tablet containing enteric-coated microgranules. The effect of compression on dissolution behavior was investigated, as compression affected cleavage and crushing ...

Journal: :Biomaterials 1999
F Madsen N A Peppas

Graft copolymer networks of poly(methacrylic acid-g-ethylene glycol) were prepared by free radical solution UV-polymerization of methacrylic acid (MAA) and poly(ethylene glycol) monomethacrylate. Dynamic swelling studies indicated that complexation/decomplexation processes occurred due to hydrogen bonding between the carboxylic groups of the poly(methacrylic acid) (PMAA) and the ether groups of...

2006
Masayoshi Okubo Toyoko Suzuki Naoki Tsuda

A novel technique to estimate the distribution state of carboxyl groups within submicron-sized, carboxylated polymer particles was proposed. For the purpose, carboxyl groups in two kinds of butyl methacrylate-methacrylic acid copolymer emulsion, which were prepared by emulsion copolymerizations with different monomer addition methods, were titrated by isothermal titration calorimetry with an ex...

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