RESUMO
<p><b>OBJECTIVE</b>To prepare a drug-loading film using chitosan and carboxymethyl chitosan as the carrier materials for delivering matrine to oral ulcers.</p><p><b>METHODS</b>Matrine-loading films using chitosan or carboxymethyl chitosan as the carrier materials were prepared by solution casting method and orthogonal experiment at room temperature. The mechanical properties, surface morphology and drug-loading capacity of the drug-loading film were characterized using tensile test, scanning electron microscopy (SEM), swelling test and in vitro drug release test.</p><p><b>RESULTS</b>When the molecular weight of chitosan was 650 000 and the mass ratio of chitosan/glycerol was 1:1.4, the prepared film had the maximum mechanical strength and tensile modulus reaching 0.7875 MPa. SEM observation showed that matrine aggregated at the bottom of the drug-loading film with an asymmetrical distribution. The in vitro drug release test showed that the film had a high drug-loading capacity and a sustained drug release property. The duration of drug release from the drug-loading film was prolonged as the molecular weight of chitosan increased, reaching 23 h when the molecular weight of chitosan was 650 000. The duration of drug release was further increased to 108 h when the bottom of the drug-loading film was coated with a layer of 1% carboxymethyl chitosan.</p><p><b>CONCLUSION</b>The matrix materials of the drug-loading film are natural, green, nontoxic and biodegradable, and the preparation of the film is simple without using large quantities of organic solvents. The novel drug-loading film can obviously prolong the duration of drugs release for better local drug delivery to oral ulcers in a sustained manner.</p>