Figure 2.

The cumulative percent release (A) and the percent release rate (B) of heparin in vitro from EVAc collars. The collars were loaded with a drug mixture that was 37.5% heparin and 62.5% BSA with a trace amount of [³H]heparin. They were coated with an impermeable layer on their outer surface so that drug release was exclusively toward the core (±SEM; n = 6). The precoated weights of these collars ranged between 83.3 and 111.1 mg, 12.5% of which was heparin.