Tolerance and percutaneous absorption of topically applied arildone

Arildone, an investigational antiviral agent, was compared to both its vanishing cream and 90% dimethyl sulfoxide (DMSO) solution vehicles to determine cutaneous and systemic tolerance as well as percutaneous absorption. In separate studies, immunosuppressed patients randomly received either arildone in vanishing cream (study 1), arildone in DMSO solution (study 2), or the vehicles without arildone. Test formulations were applied to the same area of one forearm four times daily for seven days. Blood, urine, and fecal samples were collected on days 1, 4, and 7, and patients were observed daily. Arildone was sporadically detected in biologic specimens suggesting limited percutaneous absorption. Unexpectedly, DMSO did not appear to enhance absorption of the drug. No clinical or laboratory evidence of systemic intolerance was observed for any preparation. While cutaneous tolerance was excellent for the vanishing cream preparations, the DMSO preparations were associated with a high (90%) incidence of erythematous reactions.