| Chitosan （CS）, the deacetylated derivative of chitin, has excellent biologicalproerties such as non-toxic, biocompatible, biodegradable, antibacterial and woundhealing activity. But the low mechanical strength of CS limits its further use as awound dressing materials. Polyvinyl alcohol （PVA） is a non-toxic, biodegradable,water-solubility polymer, and has good mechanical properties and film-formingability. Blends of CS and PVA can obtain a material with excellent proerties. Salicylicacid （SA） has excellent anti-inflammatory, antipyretic and analgesic effects. It alsohas a strong bactericidal and antiseptic effect. A CS/PVA blend films with SA as amodel drug can be prepared, which can be potentially applied as a drug deliverydressing materials.A series Salicylic acid-Chitosan-Poly（vinyl alcohol） blend films were preparedby the solution casting technique with different contents of Salicylic acid. Theobtained blend films were characterized by FTIR, XRD, SEM and AFM. The watervapor trausmission rate, mechanical properties and the drug release behavior werealso studied. The results indicated there was good miscibility among Salicylic acid,Chitosan and Poly（vinyl alcohol） when the content of SA≤30%. The water vaportrausmission rate and the mechanical properties of blend films were decreased asadding the contents of Salicylic acid. The sustained release action of Salicylic acidfrom blend films was observed, and the drug release ratio was increased as adding thecontent of Salicylic acid. Compared with drug release in distilled water, the far higherbalance release ratio could be seen in normal saline.N-（2-hydroxy）propyl-3-trimethylammonium chitosan chloride （HTCC） wassynthesized for improved the water-solubility of chitosan, and characterized by FTIR,1H NMR and EA. The reasults show that the degree of substitution is90.89%. Byusing distilled water as cosolvent, a series HTCC/PVA blend films with differentcompositions were prepared by solution casting technique. The characterizationresults of FTIR and TG indicated that hydrogen-bonding interaction existed between HTCC and PVA. The observation results of SEM and AFM show that the blend filmhas no obvious phase separation, and the surface roughness was decreased comparewith pure HTCC film when the contant of HTCC is70%. Obvious minutecrack isappeared and the surface roughness is increased when the contant of HTCC decreaseto50%. When the contant of HTCC is70%, the water vapor trausmission rate is thelowest among all of blend films. It is indicated that the interaction of the twopolymers is the best. The mechanical property of blend films are between pure HTCCfilm and pure PVA film.A series SA-HTCC/PVA blend films with different contants of SA and with theHTCC/PVA ratio of7/3were prepared. The characterization show that theelectrostatic interaction existed between SA and HTCC, and there was goodmiscibility among SA, HTCC and PVA. As the contants of SA increase, the surfaceroughness increase from2.038nm to19.699nm, the temperature of blend films dueinitial decomposition decrease from263℃to177℃, the water vapor trausmissionrate decrease from104.95g·m-2·h-1to57.55g·m-2·h-1, and the mechanicalproperty show decline trend.The sustained release action of SA from SA-HTCC/PVA blend films wasobserved. When blend films have the same ratio of HTCC/PVA, the more contant ofSA include, the higher drug release ratio have. The balance drug release ratio isreached to60%in distilled water and83%in normal saline when the contant of SA is30%. When blend films have20%contant of SA, the more contant of HTCC in blendfilm, the lower drug release ratio have. The balance drug release ratio is reached to78in distilled water and92%in normal saline when the HTCC/PVA ratio is1/9. Themechanism of release met the first order and Weibull distributed model. |
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