This article describes the fabrication of new pH-responsive hybrid gel beads based on combining the polymer gelator calcium alginate with two different low molecular weight gelators (LMWGs) based on 1,3:2,4-dibenzylidene-D-sorbitol: pH-responsive DBS-COOH and thermally-responsive DBS-CONHNH2, clearly demonstrating that different classes of LMWG can be fabricated into gel beads using this approach. We also demonstrate that self-assembled multi-component gel beads can be formed using different combinations of these gelators. The different gel bead formulations exhibit different responsiveness – the DBS-COOH network can disassemble within those beads in which it is present on raising the pH. To exemplify preliminary data for a potential application for these hybrid gel beads, we explored aspects of the delivery of the lipid-lowering active pharmaceutical ingredient (API) rosuvastatin. The release profile of this statin from the hybrid gel beads is pH-dependent, with greater release at pH 7.4 than at pH 4.0 – primary control of this process results from the pKa of the API. The extent of pH-mediated API release, is also significantly further modified according to gel bead composition. The DBS-COOH/alginate beads show rapid, highly effective drug release at pH 7.4, while the three-component DBS-COOH/DBS-CONHNH2/alginate system shows controlled slow release of the API under the same conditions. These initial results indicate that such gel beads constitute a promising, versatile and easily tuned platform suitable for further development for controlled drug delivery applications.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)