Liposomal sustained-release delivery systems for intravenous injection. I. Physicochemical and biological properties of newly synthesized lipophilic derivatives of mitomycin C.
A series of amino acid derivatives of cholesterol, 9α-fluorohydrocortisone, 6α-fluoro-16α-hydroxycortisone-16,17-acetonide, and 2α-methyl-5α-dihydrotestosterone have been synthesized in a further attempt to provide compounds with increased aqueous solubility. The acylable hydroxy group of the steroid was converted to the chloroformate and was then condensed with the appropriate amino acid. The potassium
Liposomal sustained-release delivery systems for intravenous injection. IV. Antitumor activity of newly synthesized lipophilic 1-.BETA.-D-arabinofuranosylcytosine prodrug-bearing liposomes.
A lipophilic prodrug of 1-β-D-arabinofuranosylcytosine (Ara-C), namely N4-[N-(cholesteryl-oxycarbonyl)glycyl]-Ara-C (COCG-Ara-C), was synthesized and its antitumor activity in a liposome-entrapped form was studied. COCG-Ara-C showed an increaesd lipophilicity and almost complete entrapment in liposomes. COCG-Ara-C was hydrolyzed to the parent drug chemically, but the hydrolysis was accelerated in the presence of mouse, rat and human plasma. The in vitro cytoxicity of the prodrug against P 388 leukemia was approximately one-fifth that of Ara-C and four times that of N4-behenoyl-Ara-C (BHAC). For in vivo antitumor activity tests, unilamellar vesicles composed of egg phosphatidylcholine (PC), egg sphingomyelin (SM) and COCG-Ara-C in a molar ratio of 7 : 3 : X (X=0-2.0) were prepared by the combination of controlled dialysis and sequential extrusion. The vesicle size ranged from 108±18 nm to 124±18 nm. In all the antitumor activity studies, chemotherapy was performed intravenously. The antitumor activity of COCG-Ara-C-bearing liposomes against intraperitoneally- or intravenously-inoculated mouse L 1210 leukemia was clearly superior to those of Ara-C and BHAC aqueous solutions. The efficacy of COCG-Ara-C against L 1210 leukemia was dependent upon the dosage form : regardless of implantation route, liposomal COCG-Ara-C showed a more potent activity than free COCG-Ara-C (aqueous solution). Prodrug-bearing liposomes also inhibited the growth of a human lung adenocarcinoma A 549 xenograft implanted under the renal capsule more efficiently than did Ara-C and BHAC aqueous solutions. These results suggest the potential usefulness of COCG-Ara-C-bearing liposomes in cancer chemotherapy.
The present invention relates to liposome preparations. In particular, the present invention relates to Adriamycin-entrapped liposome preparations comprising cholesterol derivatives having a negative charge as a liposome membrane constituent. Adriamycin-entrapped liposome preparations have many uses in the medical field such as maintaining high Adriamycin blood levels over a long period of time and reducing systemic toxicity, for example.
Prodrug compounds, process for the preparation thereof and sustained
申请人:Fujisawa Pharmaceutical Co., Ltd.
公开号:US04772594A1
公开(公告)日:1988-09-20
The invention relates to a novel prodrug compound useful in the treatment of tumors, of the formula: A--CO(CH.sub.2).sub.m (NHCO).sub.n --R wherein A is a residue of an antitumor substance having >NH or --NH.sub.2 group in the molecule, R is a residue of cholesterol, m is an integer of 1 or 2 and n is 0 or 1, and its salts.
The invention concerns lipid assemblies, liposomes having an outer surface comprising a mixture of anionic and cationic moieties; wherein at least a portion of the cationic moieties are guanido groups, and their use for serum resistant transfection of cells.