Cytarabine trapping in poly(2-hydroxyethyl methacrylate) hydrogels: drug delivery studies

The release of cytarabine (ara-c) from poly(2-hydroxyethyl methacrylate) hydrogels cross-linked with different amounts of ethyleneglycol dimethacrylate (EGDMA) has been studied. The drug (range 5-25 mg) was trapped in polymer discs by including it in the feed mixture of polymerization. The drug delivery was followed by HPLC. The release was in accordance with Fickian behaviour. Total release of ara-C was reached after between 3 and 7 days depending on the percentage of EGDMA in the gels. A constant release rate of ara-C from the hydrogels was obtained, the time depending on the degree of cross-linking of the gels: 22 h for gels with 0.5% EGDMA, 32 h for gels with 5% EGDMA and 42 h for gels with 7% EGDMA; the amount of ara-C released being 50%, 80% and 85%, respectively, of the drug load of the gel discs. An increase of the release rate with the disc load was observed for each sort of hydrogel. Neither during the loading of the gels nor right through the drug release was degradation of ara-C observed.