pH 감응성을 지닌 alginate/poly(vinyl …

1 Biomater. Res. (2013) 17(4) : 194-199194 BiomaterialsResearchCThe Korean Society for BiomaterialspH alginate /poly(vinyl alcohol)/bentonite Preparation and Characterization ofpH-sensitive Sodium alginate /poly(vinyl alcohol)/bentonite Blend Beads *Kyung Hui Jeong and Young Jin Jung* Department of Biomaterials Science, College of Natural Resources & Life Science, Pusan National University, Miryang 627-706, Korea(Received October 19, 2013 / Revised November 4, 2013 / Accepted November 5, 2013)

2 In order to enhance the drug entrapment efficiency and improve the swelling behaviors of drug delivery system, Ca2+crosslinking technique was used to prepare sodium alginate /poly(vinyl alcohol)/bentonite blend beads. Beads of dif-ferent compositions were prepared by varying the amount of bentonite and characterizing it by scanning electronmicroscopy (SEM). The swelling and pH-sensitive properties of the beads were investigated, and the drug loading andcontrolled release properties of the beads were also evaluated using diclofenac sodium as the model drug. The resultsshowed that blending PVA and bentonite with alginate beads significantly improved drug encapsulation efficiency,swelling behaviors and drug release property.

3 Key words: alginate , poly(vinyl alcohol), Bentonite, Controlled release, diclofenac sodium , . (stimuli-responsive) , (smart) , (intelligent) , , , pH, , , , . , , , .1,3) , , . pH , pH pH.

4 4) pH alginate ,5,6) chitosan7,8) hyaluronic acid4) . sodium alginate (polysaccharide) , -D-mannuronicacid -L-gluronic acid . , , , , .9) alginate . , alginate gel . , alginate bead in vitro bead .10) alginate bead.

5 Hyroxylethylcellulose,11) poly(N-isopropylacrylamide),12) gelatin13) alginate , alginate bead .14) Bentonite smectite montmorillonite . Figure 1 bentonite Si-Al-Si , , , , .15,16) bentonite - , - .17)* : pH alginate /poly(vinyl alcohol)/bentonite 195 Vol.

6 17, No. 4 Poly(vinyl alcohol)( PVA) . PVA hydrogel , , , .18,19) alginate bead PVA bentonite - bead . bead PVA bentonite , , diclofenac sodium pH bead . pH bead 80,000~12,000 sodium alginate JunseiChemical Co. Ltd (Japan) , 70,000~12,000 PVA Sigma Chemical Co.

7 (USA) ,bentonite Aldrich Chemical Co. (USA) . SA calcium chloride (CaCl2) Dae jung Chemical Co. Ltd (Korea) . diclofenac sodium , Sigma ChemicalCo. (USA) . simulated gastric fluid (SGF, ) HCl mL, KCl g 3,000 mL , simulated intestinal fluid (SIF, phosphate buffersolutions, PBS, ) NaOH g, K2 HPO4 g 3000 mL . alginate /bentonite bead 4% (w/v) sodium alginate 50 ml bentonite , DS.

8 5%(w/v) CaCl . CaCl magnetic stirrer bead . bead 24 . alginate /PVA/bentonite bead 1wt% PVA 90oC 3 PVA SA 4wt% . bentonite diclofenac sodium . 5 wt % CaCl2 . CaCl2 magnetic stirrer bead . bead CaCl2 , 24 . bead 100 mg pH buffered saline (PBS) 100 ml , bead 10 4.

9 Spectrophotometry (Shimadzu , Japan) 280nm . (1) . (%) =(1) (pH ) (pH ) 37oC ( , 1,2, 3, 4, 6, 8 h) bead , (2) . (%) =(2) bead contactangle meter (AMS2001 G-1, Mirero system, Korea) . In vitro bead sample shaking incubator 150 1rpm . bead (pH ) , (pH ).

10 Sample , sample . spectrophotometry (Shimadzu , Japan) , diclofenac sodium 280 nm (bead ) ( )--------------------------------------- -------------------------100 Wswell Wdry ()Wdry---------------------------------- ---------100 Figure 1. Bentonite is composed of three layers of silicon and alu-minum clay. When the bentonite is swollen in water, it becomes elec-trically charged, which imparts adsorption Biomaterials Research 2013.