Dextrans--potential polymeric drug carriers for flurbiprofen.

Dextrans have been used as carrier for flurbiprofen. Conjugates of flurbiprofen were synthesized by preparing their acylimidazol derivatives which were condensed in situ with dextrans of different molecular weight (40,000, 60,000, 110,000 and 200,000). The structures of the synthesized conjugates were confirmed by IR and NMR spectroscopy. The degrees of substitution were obtained between 8.0 to 9.5% and molecular weight was determined by Mark-Howin Sakurada viscosity equation. A hydrolysis study was performed in different buffer solutions (pH 1.2, 7.4, 9.0) and 80% human plasma (pH 7.4). The hydrolysis followed first order kinetics. Much faster hydrolysis was observed at pH 9.0 compared to buffer solution pH 7.4 and 80% human plasma (pH 7.4). The biological evaluation for acute and chronic anti-inflammatory activity was performed and the results were found to be comparable with the parent drug. The conjugates showed remarkable reduction in ulcerogenicity compared to parent flurbiprofen.