Crosslinking of poly(N-vinyl pyrrolidone-co-n-butyl methacrylate) copolymers for controlled drug delivery

摘要

Poly(N-vinyl pyrrolidone-co-n-butyl methacrylate) P(NVP-co-nBMA) copolymers containing high N-vinyl pyrrolidone content were crosslinked to increase their hydro-stable nature for controlled drug delivery. Diethylene glycol dimethac-rylate (DEGDMA) and trimethylolpropane trimethacrylate (TMPTMA) were used as crosslinkers. The effect of crosslinker concentration and functionality on gel content, thermal stability and water uptake at 37 °C was investigated. The gel contents and thermal stability increased while water uptake decreased with increasing concentration and functionality of crosslinker. The copolymer crosslinked by TMPTMA showed good mechanical properties. The porous network structure of the copolymers was confirmed by scanning electron microscopic studies. Dexamethasone was selected as a model drug and its controlled release was observed for 22 days from TMPTMA crosslinked copolymer (NB91-T2) film, whereas 96 % drug was released in 35 days for DEGDMA crosslinked copolymer (NB91-D2) film. The kinetics of 10 h drug release identified first-order drug release for NB91-D2 and Higuchi kinetics for NB91-T2. The initial 60 % drug release followed non-Fickian diffusion mechanism. These results indicate the future application of NB91-D2 and NB91-T2 copolymer films as a drug carrier for implant coatings.