Acute local irritative effect of (2''R)-4'-O-tetrahydropyranyladriamycin, a new antitumor antibiotic.

(2"R)-4'-O-Tetrahydropyranyladriamycin hydrochloride (THP), a new antitumor antibiotic, was administered to rabbits at a concentration from 0.02 to 0.5% by instillation, or by intracutaneous, subcutaneous or intramuscular injection to study its local irritative effect. The irritative effect of THP increased with concentration. At a concentration of 0.5%, THP was irritant to the eye, skin and muscle but at a concentration of 0.1% practically no effect was observed. The effect was equal to or lower than that of doxorubicin. An instillation of 0.5% THP caused reversible irritation effect on the eye. Slight conjunctival responses (redness and chemoisis) were observed. Rinsing reduced the irritative effect. Intracutaneous injection of 0.1 ml of 0.5% THP caused well defined, moderate erythema, surface ulceration and dermal necrosis. Cutaneous muscle necrosis also occurred. At a concentration of 0.02%, dermal necrosis and inflammatory cell infiltration were observed. Erythema, as well as muscle necrosis and calcification with giant cell reaction and inflammatory cell infiltration were observed by an intramuscular injection at a concentration of 0.5%. Subcutaneous injection of 0.5% THP showed no irritative effect.