Abstract
Cholic acid hydrazide-dextran conjugates (CAH-DEX's) with stable acryl hydrazone linkages were synthesized from cholic acid hydrazide and poly(aldehyde dextran) and were characterized by Fourier transform infrared (FTIR) spectroscopy, 1H-NMR, and surface tension measurements. The conjugates developed a lower critical aggregation concentration, which was determined by 1,6-diphenyl-1,3,5-hexatriene dye solubilization methods, 1.41 and 2.10 × 10-2 mg/mL for CAH-DEX 9.0 and CAH-DEX 6.5, respectively. A hydrophobic drug, indomethacin (IN), was physically entrapped inside the self-aggregates, and the IN-loaded self-aggregates were analyzed with a dynamic light-scattering system, transmission electron microscopy, and atomic force microscopy. The maximum loading of IN reached 29.9% of the CAH-DEX self-aggregates, which suggested a high loading efficiency of 51.2%. The size of the self-aggregates increased when the drug was entrapped. IN was released from CAH-DEX self-aggregates at pH 4 much slower than at pH 7.4, and in pH 4 media, the release profile was pseudo-zero-order in kinetic terms for up to 14 days. There was almost no change in the FTIR spectra of the CAH-DEX's, which were incubated in buffers of pH 7.4 and pH 4 for 24 h, which indicated that acryl hydrazone was considerably resistant to hydrolysis.
Original language | English (US) |
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Pages (from-to) | 487-493 |
Number of pages | 7 |
Journal | Journal of Applied Polymer Science |
Volume | 95 |
Issue number | 3 |
DOIs | |
State | Published - Feb 5 2005 |
Externally published | Yes |
Keywords
- Cholic acid
- Colloids
- Conjugated polymer
- Dextran
- Drug delivery systems
ASJC Scopus subject areas
- General Chemistry
- Surfaces, Coatings and Films
- Polymers and Plastics
- Materials Chemistry