Evaluation of alginate–chitosan bioadhesive beads as a drug delivery system for the controlled release of theophylline

Abstract

This study describes the preparation of mucoadhesive alginate-chitosan beads containing theophylline intended for colon-specific delivery. The calcium alginate beads were coated with chitosan by the ionotropic hydrogelation method with a polyelectrolyte complex reaction between two oppositely charged polyions. The release profiles of theophylline from the beads were determined by ultraviolet-visible absorption measurement at 272 nm. Scanning electron microscopy was used for morphology observation. The in vitro mucoadhesive tests for particles were carried out with the freshly excised jejunum of Sprague-Dawley rats. The bead particles, which ranged in size from 200 to 400 lm, exhibited excellent mucoadhesive properties. The results showed that the formulated coated beads succeeded in controlling the release of theophylline over a 24-h period. In conclusion, the release of theophylline was found to be dependent on the composition of the beads, the component polymer and its possible interactions, and the bioadhesiveness.

Chitosan Cross-Linked Pentasodium Tripolyphosphate Micro/Nanoparticles Produced by Ionotropic Gelation

“…Among these methods, the ionotropic gelation is based on electrostatic interaction between the amine group of chitosan and the negatively charged group of a polyanion (Hudson and Margaritis 2014;Nagpal et al 2010), such as pentasodium tripolyphosphate (Li et al 2010;Shu and Zhu 2002), alginate (Elzatahry et al 2009), hyaluronic acid (Oyarzun-Ampuero et al 2009), glutaraldehyde, glyoxal and ethylene glycol diglycidyl ether (Akbuga and Durmaz 1994). It is a simple and cheap process and has the advantage of avoiding the use of organic solvents (Shu and Zhu 2002).…”

Alginate based scaffolds for bone tissue engineering

“…According to previous studies, an ideal scaffold for BTE application should present an average pore diameter of at least 100 μm in order to allow cell migration, tissue ingrowth and even vascularization [37]. For this reason, it is possible to anticipate that, when considering pore size, both scaffolds are adequate for such application.…”

“…5A and C). The bonding of the alginate MP and MF is explained by the bioadhesive character of the alginate polymer, which results from the union of adjacent MP or MF at their contact points to form these alginate porous matrices [37,38].…”

Alginate graft copolymers and alginate–co-excipient physical mixture in oral drug delivery

“…[38][39][40][41][42][43][44] The drug release property of an alginate matrix is strongly governed by the composition of the uronic acid sequences. [1,105,106] The mannuronic acid-rich alginate matrix gives lower drug release rates in dissolution medium of pH 1.2 but higher drug release rates at pH 6.8 when compared with guluronic acid-rich Beads [6,[64][65][66][67][68][69][70][71][72][73][74] Chitosan is introduced as chitosan membrane or directly as alginate-chitosan blend in alginate beads crosslinked by calcium chloride via ionotropic gelation method. The alginate-chitosan beads can be further crosslinked through reacting chitosan with sodium sulfate.…”