Thalassemia, a genetic blood disorder, occurs as a result of deformations of hemoglobin structures. Patients with thalassemia develop iron overload from chronic blood transfusions and require regular iron chelation to prevent potentially fatal iron-related complications. Deferiprone is a commercially available drug used as iron chelator for the treatment of thalassemia but the very long-term effectiveness is not clearly known yet. Therefore, some studies were carried out to find effective alternative drugs or delivery methods for treatment of thalassemia. Controlled delivery, which offers safer, more convenient, and more effective means of administering actives, seems promising with this respect. Chitosan, a natural biopolymer produced from deacetylation of chitin, has a variety of promising pharmaceutical uses and is presently considered as a novel carrier material in drug delivery systems.
In this study, chitosan microspheres having different degree of deacetylation (DDA) and containing Deferiprone were prepared by oil/water emulsion method and by crosslinking with gluteraldehyde. Particle size, SEM, and in vitro drug release analysis were performed. The average sizes of the prepared microspheres increased with increasing degree of deacetylation of chitosan and with decreasing crosslinking degree. In vitro drug release studies showed that, the release rate of Deferiprone increased as the crosslinking degree increased, contrary to the expectations. This is explained by the crystalline structure of lightly crosslinked chitosan which have ordered and dense structure causing slower release rate for Deferiprone compare to highly crosslinked structures.
In the second stage of the study, chitosan films hardened with gluteraldehyde were prepared by film casting method. IR, DSC and mechanical analysis were performed. For the films with various crosslinking degrees, it was found that UTS values differed from 50.6 MPa to 102.7 MPa, mean elastic modulus values differed from 3328.7 MPa to 3790.1 MPa and SAB values differed from 2.06% to 4.29%.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/2/1252659/index.pdf |
| Date | 01 September 2003 |
| Creators | Uylukcuoglu, Beyza |
| Contributors | Hasirci, Nesrin |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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