The distribution of an oil-based corticosteroid following intralymphatic infusion

Following infusion of tritium labeled clobetasol propionate in Ultrafluid Lipidol (UFL) into a right hind limb lymphatic of rabbits, the radioactivity levels in various tissues at intervals up to 28 days were determined by liquid scintillation counting. There was a rapid decline in activity in the right popliteal node over the first three days due to early bloodstream absorption. From three to 28 days radioactivity levels were consistently higher in the right popliteal node and lung than in other tissues sampled. This distribution suggests that there is an affinity between clobetasol and the lipidol vehicle which retards (but does not prevent) free diffusion of this agent out of lymphatic tissues. Thus, while permitting generalized perfusion of tissues by clobetasol propionate, intralymphatic infusion maximizes its initial concentration and duration of activity within specific node groups and, therefore, may be useful in certain patients with primary lymphedema where lymph nodes affected by fibrosis constitute a major site of obstruction.