| 摘要 |
Compounds being polyethylene glycol derivatised, pharmacologically acceptable, tumour locating dihydro or tetrahydro porphyrins of formulae (4, 5 and 6), wherein R<1>n may be -OH but in at least two instances is a chain of formula (-O-Xp-[CH2CH2O]m-Y)n wherein n = 1 to 3, m = 5 to 250 and p = 0 to 1; the group Y may be a C1-C12 alkyl or acyl group but preferably a methyl group; the linking group X may be present or absent, but if present may be of the following alternative forms: R<2> = -(C=O)-(CH2)q-O- where q = 1 to 5; R<3> = -CH2-CH(OH)-(CH2)s-O- where s = 1 to 4; R<4> = -(C=O)-(CH2)t-(C=O)-O- where t = 1 to 4. Improved tumour localisation of polyether-substituted photosensitising compounds is given leading to their more efficient uptake into tumour cells. Lower overall doses of drug give an improved side-effect profile of the treatment especially with regard to skin photosensitisation. |
