Preparation and cytotoxic activity of poly(ethylene glycol)-modified poly(amidoamine) dendrimers bearing adriamycin.
Excretion and autoradiographic distribution studies were performed in rats with two 14C-labelled polyvinylpyrrolidone preparations, both of relatively low mean molecular weight but different in molecular weight distribution. At different time intervals after i.v. administration, elimination of radioactivity was found to be more complete for the preparation with the smallest fraction of molecules having a weight of over 25000, which is approximately the weight limit for rapid glomerular filtration in the rat. Our study demonstrates that the retention of PVP in organs, which in the literature are mentioned as target organs for PVP-toxicity, can be largely prevented by decreasing the fraction of molecules with a weight of more than 25000.