Carboxymethylation of kappa-carrageenan for intestinal-targeted delivery of bioactive macromolecules
Document Type
Article
Publication Date
1-1-2011
Abstract
The work presented herein discusses the carboxymethylation of kappa-carrageenan, a natural linear polysaccharide, to afford a pH-dependent swelling property allowing for intestinal-targeted delivery of bioactive macromolecules. The carboxymethylation conditions with respect to the volume and concentration of sodium hydroxide (V(NaOH), C(NaOH)), weight of monochloroacetic acid (W(MCA)), and reaction temperature (T) were optimized using a response surface method incorporating a multivariate spline interpolation technique (RSM(s)). Fluorescein isothiocyanate-labeled dextran (FD-4; 4.4 kDa) was used as a hydrophilic macromolecule model. Beads made from encapsulating FD-4 in the carboxymethylated kappa-carrageenan displayed pH-dependent swelling and encapsulation efficiency of 74. The release of FD-4 was low (23 +/- 2) in simulated gastric fluid (SGF) and high (90 +/- 3) in simulated intestinal fluid in a 2 h dissolution study. An additional lambda-carrageenan coating on the surface of the beads further reduced the FD-4 release in SGF. These carboxymethylated kappa-carrageenan beads may provide an efficient alternative approach for the oral delivery of hydrophilic macromolecules to the intestinal tract. (C) 2010 Elsevier Ltd. All rights reserved.
Keywords
Carboxymethylation, Carrageenan, Microencapsulation, Drug delivery, Response surface methodology
Divisions
fac_med
Publication Title
Carbohydrate Polymers
Volume
83
Issue
4
Additional Information
Leong, Kok Hoong Chung, Lip Yong Noordin, Mohamed Ibrahim Mohamad, Khalit Nishikawa, Masato Onuki, Yoshinori Morishita, Mariko Takayama, Kozo