A comparison of the inhibitory activity of compounds on ocular prostaglandin biosynthesis.

In the present study, we have compared the potency of various compounds as inhibitors of prostaglandin biosynthesis in ocular tissues in vitro under standard conditions of temperature, pH, substrate concentration, and time. The nonaddic anti-inflammatory agent, indoxole, was approximately 100 times as potent as indomethacin on the anterior uvea and 25 times as potent on the conjunctiva. SU 21524 (Pirprofen) was also more potent than indomethacin on the ocular tissues. Other nonsteroidal anti-inflammatory agents such as naproxen, phenylbutazone, and oxyphenbutazone were all essentially equiactive with indomethacin on the anterior uvea, whereas indomethacin was more potent than phenylbutazone or oxyphenbutazone on the conjunctiva. Aspirin, paracetamol, and dexamethasone had little or no activity in these in vitro experiments. The pharmacologic profile of activity of the active compounds was found to differ in the ocular tissues from that in other tissues such as spleen and seminal vesicles. Since other factors such as ease of penetration and local tissue irritation may affect the final selection of compounds for use as topical anti-inflammatory agents, the next step would be to evaluate the effects of compounds found to be active in the present experiments by this route of administration.