title: Novel semi-IPN based on crosslinked carboxymethyl starch and clay for the in vitro release of theophylline.
abstract: A novel semi-interpenetrating polymer network (IPN) based on crosslinked carboxymethyl starch (CL-CMS) and montmorillonite (MMT) was prepared, where carboxymethylation occurs as a result of the reaction between native starch and monochloroacetic acid in isopropanol/water medium at 60°C. The carboxymethyl starch is further crosslinked and made into a semi-IPN with MMT for the release of theophylline. The drug carrier was characterized using FTIR, XRD and surface analysis using SEM. Studies including physio-chemical analysis, swelling behavior, encapsulation efficiency, effect of MMT content, effect of ionic strength and in vitro drug release were carried out. Theophylline encapsulation of up to 74% was achieved and drug release was monitored in SGF (pH 1.2) and SIF (pH 7.4). Results show that the matrix releases drug at a much faster rate in the basic medium than in the acidic medium, thereby holding the promise of developing the semi-IPN system as a potential candidate for the release of theophylline.
authors.affiliation: Department of Chemistry, School of Physical and Mathematical Sciences, University of Kerala, Kariavattom, Trivandrum 695 581, India. Electronic address: tsani@rediffmail.com.
authors.forename: T S
authors.initials: TS
authors.lastname: Anirudhan
authors.affiliation: Department of Chemistry, School of Physical and Mathematical Sciences, University of Kerala, Kariavattom, Trivandrum 695 581, India.
authors.forename: J
authors.initials: J
authors.lastname: Parvathy
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D001546:Bentonite / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry; D000077215:Clay; D004337:Drug Carriers / Q000737:chemistry; D006801:Humans; D020100:Hydrogels / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D011108:Polymers / Q000737:chemistry; D013213:Starch / Q000031:analogs & derivatives* / Q000737:chemistry; D013806:Theophylline / Q000737:chemistry*
chemical_list: D000538:Aluminum Silicates; D004337:Drug Carriers; D020100:Hydrogels; D011108:Polymers; D001546:Bentonite; D013213:Starch; D048271:Chitosan; C034848:carboxymethyl starch; D013806:Theophylline; D000077215:Clay
keywords: Carboxymethyl starch; Semi-interpenetrating polymer network; Starch; Theophylline