Non-stealth and stealth solid lipid nanoparticles (SLN) carrying doxorubicin: Pharmacokinetics and tissue distribution after i.v. administration to rats

Non-stealth and stealth solid lipid nanoparticles (SLN) carrying doxorubici n were prepared as drug delivery systems. The pharmacokinetics and tissue d istribution of doxorubicin in these SLN were studied after i.v. administrat ion to conscious rats and were compared to the commercial solution of doxor ubicin. The same dose of each formulation (6 mg kg(-1) of body weight) of d oxorubicin was injected in the rat jugular vein. Blood samples were collect ed after 1, 15, 30, 45, 60 min and 2, 3, 6, 12, and 24 h after the injectio n. Rats were sacrificed after intervals of 30 min, 4 h, and 24 h and sample s of liver, spleen, heart, lung, kidney, and brain were collected. In all s amples, the concentration of doxorubicin and of the metabolite, doxorubicin ol, were determined. Doxorubicin and doxorubicinol were still present in th e blood 24 h after injection of stealth and non-stealth SLN, while they wer e not detectable after the injection of the commercial solution. The result s confirmed the prolonged circulation time of the SLN compared to the doxor ubicin solution. In all rat tissues, except the brain, the amount of doxoru bicin was always lower after the injection of the two types of SLN than aft er the injection of the commercial solution. In particular, SLN significant ly decreased the heart concentration of doxorubicin. (C) 2000 Academic Pres s.