The Synthesis,Characterization And Drug Release Of Azo-Containing Hydrogel

Colon-specific drug delivery system(CDDS) can deliver bioactive compounds to colon without release in upper gastrointestinal. The conventional methods for obtain CDDS include:(1)pH-dependent;(2)the passage of time and (3)enzyme-based(he enzymes found locally in a region of the gut breakdown a prodrug or a formulation to release drug).In this paper, the azo-containing dextran was synthesized and characterized. Then the relation between the character of hydrogels and crosslinking degree was studied. The BSA release from hydrogels in vitro proved that: this hydrogels are sensitive to azoductase, which can be used as drug carrier for colon-specific drug delivery system.Using dicyclohexyl carbodiimide(DCC) as coupling agent, N,N'-dimethylamino-pyridine(DMAP) as base catalyst, di-(2-hydroxyethyl) 5,5'-azodisalicylate was synthesized. And then IPDI reacted with di-(2-hydroxyethyl) 5,5'-azodisalicylate;the isocyanate of this production can react as crosslinking agent with the hydroxyl on dextran to form hydrogels. Many methods such as FT-IR and NMR make out the feasibility of this synthesis.The determine of swelling behavior of hydrogels demonstrated the relation between crosslinking degree and the max swelling ratio. The study on BSA release from hydrogels in PBS and RCCRM indicated the sensitivity of the hydrogels to azoreductase, which illustrated that this hydrogels can be used as carriers for colon-specific drug delivery system. The SEM photograph of swelling and degradated hydrogels indicated the porous structure of hydrogels and the factors influenced hydrogels' degreadation.