Study Of The Controlled Drug Releasing Behavior Of A Chitosan-based Polyelectrolyte Complex

The drug controlled release system has attracted scholars' research interest due to its various advantages in low toxic and side effects,controlling drug release speed,and reducing the number of administrations.Membrane penetration controlled release is a common drug controlled release system.Drug is encapsulated in the polyelectrolyte complex membrane layer.Drug release process is complicated,involving swelling and degradation of membrane,diffusion of drug in the polymer network and multiple processes.As natural degradable polymers,carboxymethyl chitosan and sodium alginate are common drug loading matrix material,which have good biocompatibility and biodegradability.Carboxymethyl chitosan is an amphoteric polyelectrolyte,Sodium alginate is a natural anionic polyelectrolyte.After being treated with acetic acid,the amino protonation of carboxymethyl chitosan is positively charged and can be electrostatically interacted with the carboxyl groups to form a uniform hydrogel.In this paper,carboxymethyl chitosan and sodium alginate are used as raw materials to systematically study the microstructure of carboxymethyl chitosan/sodium alginate polyelectrolyte hydrogel,as well as the swelling properties,mechanical properties and in vitro properties of the hydrogel membrane.The osmotic behavior is expected to achieve effective regulation of drug release behavior in vitro by adjusting the membrane material composition.The main research contents are as follows:1.N,O-carboxymethyl chitosan was prepared by chloroacetic acid method,the strong characteristic peaks at 1605 cm-1 and 1403 cm-1 indicated the successful introduction of carboxymethyl group to chitosan.Potentiometric titration method was used to measure the degree of substitution and deacetylation of N,O-carboxymethyl chitosan,DS and DD were 74%and 86%,respectively.2.Under the acetic acid atmosphere,the carboxymethyl chitosan/sodium alginate polyelectrolyte hydrogels were successfully prepared by solution casting technology.Studies showed the porous microstructure of the freeze-dried hydrogels with an average pore size of about 80 ?m.FTIR,UV,TG-DTA showed that the amino group of carboxymethyl chitosan and the carboxyl group of sodium alginate electrostatically interacted to form hydrogels.Under the condition that the carboxymethyl chitosan/sodium alginate polyelectrolyte hydrogel membrane has excellent mechanical properties,by simply adjusting the ratio of carboxymethyl chitosan and sodium alginate,the swelling rates of the hydrogel membranes could be adjusted from 5.78 to 22.16.3.Using diclofenac diethylamine as the model drug,we studied the drug release behavior of carboxymethyl chitosan/sodium alginate polyelectrolyte hydrogel membranes.The study found that the drug penetration curve conformed to the Korsmeyer-Peppas model.By optimizing the ratio of carboxymethyl chitosan and sodium alginate,near zero-order kinetic drug release could be achieved.The above research shows that carboxymethyl chitosan/sodium alginate polyelectrolyte hydrogel membrane can effectively control the drug release rate,and can be used to regulate osmotic behavior and develop advanced drug delivery systems.