Fluidized-bed spray coated porous hydrogel beads for sustained release of diclofenac sodium

Sun, YM; Chang, CC; Huang, WF; Liang, HC

HERO ID

4829001

Reference Type

Journal Article

Year

1997

HERO ID 4829001
In Press No
Year 1997
Title Fluidized-bed spray coated porous hydrogel beads for sustained release of diclofenac sodium
Authors Sun, YM; Chang, CC; Huang, WF; Liang, HC
Journal Journal of Controlled Release
Volume 47
Issue 3
Page Numbers 247-260
Abstract Swellable porous hydrogel beads were loaded with diclofenac sodium and then coated with pseudo-latex ethylcellulose (EC) in a fluidized-bed spray coater. The drug release profile in-vitro can be modified by adding 25% or more triethyl citrate (TEC) or dibutyl sebacate (DBS) as a plasticizer. The plasticized coating film can overcome the swelling stress of the core and function as a barrier for sustained drug release. Adding TEC resulted in a near-zero order kinetics after an initial burst in the release profile, and adding DBS showed a first initial burst, a second stage of linear release, a third stage of slow release. The initial burst is due to the flaws or cracks on the surface of the coated-beads and it can be reduced by increasing the amount of plasticizer or film thickness and also by adjusting the thermal treatment time. A 4- to 6-h treatment at 60 degrees C was found to be the optimal condition to give the smallest initial burst for coating film containing TEC as a plasticizer. Adding hydrophilic hydroxylpropyl methylcellulose (HPMC) could smooth the initial burst and change the release profile to a Fickian-type release, and in this case increasing the thermal treatment time could reduce the release rate. Two kinds of EC-coated beads were tested in-vivo by using rabbits as animal models and showed good sustained release behaviors as the drug concentration in plasma could be maintained above 0.4 mu g/ml and lower than 1.5 mu g/ml for 24 h. (C) 1997 Elsevier Science Ireland Ltd.
Doi 10.1016/S0168-3659(97)01649-0
Wosid WOS:A1997XD26800004
Is Certified Translation No
Dupe Override No
Is Public Yes
Keyword microencapsulation; hydrogel; diclofenac sodium; fluidized-bed; spray coating; ethylcellulose