Pharmacokinetic studies with zinc(II)-phthalocyanine in tumour-bearing mice.
Zn(II)-phthalocyanine (Zn-Pc) incorporated into unilamellar liposomes of dipalmitoylphosphatidylcholine has been injected intraperitoneally (0.5 mg kg-1) to BALB/c mice bearing a transplanted MS-2 fibrosarcoma. The drug is specifically transported by serum lipoproteins and cleared from the serum via the bile-gut pathway in a biphasic process: approximately 60% of Zn-Pc is eliminated with a serum half-life of approximately 9 hours, while the remaining aliquot is eliminated at a very slow rate. Several normal tissues take up the drug within 3 hours after administration but release it almost completely after 24-48 hours. On the other hand, the tumour shows a maximum concentration of Zn-Pc (approximately 0.6 microgram g-1 of tissue) after 18-24 hours; at this time, the ratio between the Zn-Pc levels in the tumour and the muscle (which represents the surrounding normal tissue) is approximately 7.5. The results are discussed in terms of a possible use of Zn-Pc as a photosensitizer in the photodynamic therapy of tumours.
Department of Biology, University of Padova, Italy.
E
E
Reddi
G
G
Lo Castro
R
R
Biolo
G
G
Jori
D000818:Animals; D005260:Female; D005354:Fibrosarcoma / Q000097:blood / Q000378:metabolism*; D006207:Half-Life; D007211:Indoles / Q000097:blood / Q000493:pharmacokinetics*; D054833:Isoindoles; D008074:Lipoproteins / Q000097:blood; D008081:Liposomes; D051379:Mice; D008807:Mice, Inbred BALB C; D009132:Muscles / Q000378:metabolism; D009942:Organometallic Compounds / Q000097:blood / Q000493:pharmacokinetics*; D010860:Pigments, Biological / Q000097:blood / Q000493:pharmacokinetics*; D051381:Rats; D013997:Time Factors; D014018:Tissue Distribution; D015032:Zinc / Q000097:blood / Q000493:pharmacokinetics*; D017967:Zinc Compounds
D007211:Indoles; D054833:Isoindoles; D008074:Lipoproteins; D008081:Liposomes; D009942:Organometallic Compounds; D010860:Pigments, Biological; D017967:Zinc Compounds; C052159:Zn(II)-phthalocyanine; D015032:Zinc