50 50 POLY(DL GLYCOLIC ACID LACTIC-ACID) COPOLYMER AS A DRUG-DELIVERYSYSTEM FOR 5-FLUOROURACIL - A HISTOPATHOLOGICAL EVALUATION/

Fifty:fifty poly (DL glycolic acid-lactic acid) copolymer (PGLA) is a potentially useful depot drug delivery system for 5-fluorouracil (5 FU ). The purpose of this study was to evaluate the fibroinflammatory rea ction induced by this polymer. Polymer discs without 5-FU were inserte d subconjunctivally in one eye of each of two guinea pigs and four pig mented rabbits (control group), and discs containing 20% 5-FU were ins erted subconjunctivally in both eyes of nine pigmented rabbits (study group). The tissue reaction to the copolymer did not differ between ra bbits and guinea pigs, with a mild mixed inflammatory reaction 1 week after implantation. At 2 weeks a thin fibrous capsule surrounded the d iscs, with no change in the amount of inflammation. At 4 weeks the dis c had disintegrated, but residual polymer was seen within multinucleat ed giant cells in the episcleral tissue. Granulation tissue and inflam matory responses were mild. Less inflammation and fibrosis occurred in the study eyes, although the pattern of response was similar in the t wo groups. The inflammatory response to PGLA was markedly less than th at to implanted collagen shields, and our findings suggest that PGLA i mplant is a promising ocular drug delivery system for 5 FU after filtr ation surgery.