Release of 14 C-INS from QD- 14 C-INS–CS/GS was examined in a dual-chamber system. Cleavage of CS/GS and removal of QDs were promoted by enzyme co-incubation (i). The dual-chamber system was separated by a 10.0 kDa membrane (ii) and allowed only free insulin (5.8 kDa) to pass through the second chamber (iii). Release was strongly dependent on co-incubation with hydrolysing enzymes (cellulase and beta-glucosidase), with 50% release within 60 min. Decreased pH and increased temperature also increased the drug release.
