H. Brondsted et al., CROSS-LINKED DEXTRAN - A NEW CAPSULE MATERIAL FOR COLON TARGETING OF DRUGS, Journal of controlled release, 53(1-3), 1998, pp. 7-13
In the work presented here we have studied the application of glutaral
dehyde crosslinked dextran as a capsule material for colon-specific dr
ug delivery. A reaction mixture containing dextran, MgCl2, glutaraldeh
yde and polyethyleneglycol 400 in water was applied onto molding pins
of nylon producing capsule caps and bodies. The capsule materials were
characterized by measuring of the mechanical strength in compression
and equilibrium degree of swelling. Based on these results an optimal
composition for the capsule material was selected. The dextran capsule
s were loaded with hydrocortisone and subsequently, drug release was s
tudied. The release was found to be about 10% during the initial 3 h i
n a buffer solution. Over a period of 24 h the release was about 35%.
However, when the dextran capsules were challenged with a dextranase s
olution, simulating the arrival of the drug delivery system to the col
on, the capsules quickly broke and the drug was released as a dose dum
p. The study shows that the dextran capsules are promising candidates
for providing a colon-specific drug delivery. (C) 1998 Elsevier Scienc
e B.V.