title: Oral delivery of insulin using chitosan capsules cross-linked with phytic acid.
abstract: Phytic acid (PA) was used as a cross-linking agent for encapsulation of insulin in a chitosan matrix for oral delivery of insulin. PA-chitosan capsules were compared with tripolyphosphate (TPP)-chitosan capsules for stable oral delivery of insulin. During 2 h incubation in simulated gastric fluid, PA-chitosan capsules prepared using pH 6, 6% PA solutions showed better stability than TPP-chitosan capsules prepared using pH 7, 6% TTP solution. PA-chitosan capsules released less than 60% of their encapsulated insulin after 24 h incubation in simulated gastrointestinal fluids. TPP-chitosan capsules showed burst release and virtually the entire insulin content was released in 12 h. Both capsule types were tested in vivo via oral drug administration using diabetic mice. PA-chitosan capsules significantly decreased blood glucose levels while TPP-chitosan capsules caused a lesser reduction. The relative pharmacological bioactivity of PA-chitosan capsules prepared was 6.4% while that of TPP-chitosan capsules was 1.1%. PA-chitosan capsules appeared to have good potential for use in oral delivery of insulin for sustained control of the blood glucose level.
authors.affiliation: Department of Biotechnology, Yonsei University, Seoul, Korea.
authors.forename: Hyunah
authors.initials: H
authors.lastname: Lee
authors.forename: Chanmin
authors.initials: C
authors.lastname: Jeong
authors.forename: Kashif
authors.initials: K
authors.lastname: Ghafoor
authors.forename: Sungyeon
authors.initials: S
authors.lastname: Cho
authors.forename: Jiyong
authors.initials: J
authors.lastname: Park
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002214:Capsules; D048271:Chitosan / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy*; D004337:Drug Carriers / Q000737:chemistry; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000097:blood / Q000627:therapeutic use; D007328:Insulin / Q000008:administration & dosage* / Q000097:blood / Q000627:therapeutic use; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010833:Phytic Acid / Q000737:chemistry*
chemical_list: D002214:Capsules; D003432:Cross-Linking Reagents; D004337:Drug Carriers; D007004:Hypoglycemic Agents; D007328:Insulin; D010833:Phytic Acid; D048271:Chitosan