pH-sensitive interpenetrating network hydrogels based on pachyman and its carboxymethylated derivatives for oral drug delivery

pH-sensitive, interpenetrating polymer network hydrogels were synthesized based on pachyman and its carboxymethylated derivatives (CMP) by the confunctional crosslinker agent epichlorohydrin. The structure and morphology of pachyman/CMP (CPCS) hydrogels were characterized. In the swelling assays, the composite hydrogels maintained remarkable swelling capacity and significant good pH sensitivity. The swelling behavior was much improved by the incorporation of CMP than the pure pachyman hydrogels. While increasing the content of CMP in the hydrogels, the equilibrium swelling time was more reduced and the swelling ratio increased obviously due to the better water solubility of CMP. In the drug release study, the results indicated that CPCS hydrogels demonstrate better pH-resistant sustained drug release for bovine serum albumin, and the adjustment of the proportion of pachyman to CMP results in improved drug release behavior, which suggests that the CPCS hydrogels are promising candidates for sustained drug delivery system.