Studies on pharmacokinetics of sulfonated aluminum phthalocyanine in a transplantable mouse tumor by in vivo fluorescence.

The pharmacokinetic properties of sulfonated aluminum phthalocyanine (A1PCS) in mouse bearing transplantable S180 tumors were determined by an in vivo method. In vivo fluorescence measurements were made on the hind legs of mice, one leg bearing a tumor and the other, without a tumor, being used as a control. These in vivo data were compared with the results obtained from in vitro extraction fluorescence experiments. The results obtained by the two methods showed remarkable agreement, both procedures demonstrating that the concentration of A1PCS in the tumor was substantially higher than that in muscle. In both cases, the maximum tumor to muscle A1PCS concentration ratio occurred at 24-36 h after drug administration. The agreement between the in vivo and in vitro measurements shows that the in vivo fluorescence technique can be used successfully in pharmacokinetic studies of metallo-phthalocyanines in a superficial tumor model. The in vivo technique has the advantages of being rapid and convenient.