This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (3) Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Mahkam, M. Articles by Ranaei-Siadat, S. E. Search for Related Content Social Bookmarking                         What's this?

An Oral Delivery System for Insulin

Chemistry Department, Azerbaijan University of Tarbiat Moallem, Tabriz, Iran, mmahkam{at}yahoo.com, mahkam{at}azaruniv.edu

M. Allahverdipoor

Chemistry Department, Azerbaijan University of Tarbiat Moallem, Tabriz, Iran

R. Mohammadi

Chemistry Department, Azerbaijan University of Tarbiat Moallem, Tabriz, Iran

S. O. Ranaei-Siadat

Department of Biology, Faculty of Science, Shahed University, Tehran, Iran

M. R. Rashidi

Drug Applied Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran

S. Davaran

Drug Applied Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran

M. Barshan

Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran

S. E. Ranaei-Siadat

Department of Biology, Faculty of Science, Ferdowsi University, Meshhad, Iran

Crosslinked 2-hydroxyethyl methacrylate (HEMA) and methacrylic acid (MAA) copolymer hydrogels were studied as drug delivery systems. Terephthalic acid was covalently linked with 2-hydroxyethyl methacrylate (HEMA), abbreviated as cross-linking agent (CA). Free radical copolymerization of HEMA and MAA with terephthetalic acid (CA) (2, 4, and 6%) as crosslinking agent were carried out at 70°C. The structure of the CA was confirmed by FT-IR, ¹H-NMR and ¹³C-NMR spectroscopy. The composition of the crosslinked three-dimensional polymers were determined by FTIR spectroscopy. Glass transition temperature (Tg) of the network polymers was determined calorimetrically. The effect of copolymer composition on the swelling behavior and hydrolytic degradation was studied in simulated gastric fluid (SGF, pH 1) and simulated intestinal fluid (SIF, pH 7.4). The swelling and hydrolytic behavior of the copolymers depended on the content of MAA which caused a decrease in gel swelling in SGF or an increase in gel swelling in SIF. It was observed that in acidic media hydrogen bonds formed due to the protonation of the carboxylic acid groups of the MAA while in more basic or neutral conditions electrostatic repulsion occurred between the ionized carboxylic acid groups. This complex behavior affected the macroscopic swelling properties of the resultant hydrogels. The amount of drug release depended on the degree of hydrogel swelling and crosslinking.

Key Words: hydrogel • swelling • peroral • insulin • crosslinking • simulated gastic fluids

Journal of Bioactive and Compatible Polymers, Vol. 21, No. 2, 135-148 (2006)
DOI: 10.1177/0883911506063212


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				C.-Y. Chen, Qi Long, X.-H. Li, and Jiao Xu Microwave-assisted Preparation of Magnetic Albumin Microspheres Journal of Bioactive and Compatible Polymers, September 1, 2008; 23(5): 490 - 500. [Abstract] [PDF]