In vitro Characterization of Physically Reinforced Ocular Inserts of Indomethacin

Abstract

Physical reinforcements of polyvinyl alcohol (PVA; high - 125,000 and low - 14,000 molecular weights) based ocular inserts of indomethacin were conducted by subjecting to heat (80° C and 100° C for 24 and 48 hours) and freeze-thaw cycles (3 and 6 cycles). In vitro drug release was studied in a continous flow-through apparatus, and compared with the non-reinforced inserts. The rate of indomethacin release was inversely proportional to the content of low molecular weight PVA (PVA 14,000). The duration of heating had more effect on release properties than the temperature and the release pattern of freeze thawed inserts showed lower drug release than the non-reinforced and heat treated inserts.