25, 50, 100 or 150 mg once daily for 28 days.

Bovine nasal cartilage explants (25 ± 30 mg) were cultured at 37C in Dulbecco's modified Eagle's medium (DMEM) containing penicillin (50 mkg/ml, streptomycin (50 mg/ml) and fungizone (250 mg/ml). Degradation of collagen was induced by the addition of114 ng/ml of rHu-IL-1alpha to the culture medium, the cultures were incubated for 15 days. During this period culture media containing rHu-IL-1alpha and Cipemastat were renewed every 7 days. When a considerable portion of each cartilage piece had degraded, the assay was stopped by removing the remaining cartilage explant and then analyzed for hydroxyproline, as a marker of cartilage collagen content. Glucose utilization was determined by measuring the glucose concentration in culture medium around the explants at the end of the experiment. The samples were analyzed by a COBAS Bio (Roche Diagnostics) with a GlucHK-unimate 5 test kit. Ro 32-3555 inhibited interleukin-1a (IL-1a)-induced cartilage collagen degradation in vitro in bovine nasal cartilage explants with IC50=60 nM.