Azo containing polyurethanes for drug delivery to the large intestines
US5225514A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 24, 1991 |
| Grant date | Jul 6, 1993 |
| Priority date | — |
| Expiry date | Dec 24, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G2230/00
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
A polyurethane (I) of 1000 to 100,000 in average molecular weight, comprising plural segments, which are each structural units of A-B, A-C and A-D of the formulae: ##STR1## the proportion of the said segments of A-B, A-C and A-D, i.e. x:y:z is in the molar ratio 0.01 to 0.8:0 to 0.80:0 to 0.99, provided that the sum of x, y and z is 1.0; each segment being produced by combining with repeat units of A, B, C and D of the formulae: ##STR2## wherein R.sup.1 is a skeleton of a diisocyanate and the three R.sup.1 's in each of segments A-B, A-C and A-D can be the same or different; aza is a group of the formula: ##STR3## wherein Y.sup.1 and Y.sup.2 which can be the same or different, are oxygen, imino(--NH--) or a group of the formula: EQU *R.sup.6 --O, *R.sup.6 --NH, O--R.sup.6 --O, *NHCO--R.sup.6 --NH or *CONH--R.sup.6 --NH; wherein PA0 R.sup.6 is alkylene and an atom or the end of the group, marked by * is bonded to phenyl ring; PA0 R.sup.4 and R.sup.5 each are, independently, hydrogen, halogen, nitro or phenyl; PA0 R.sup.2 is polyalkylene glycol residue; PA0 Z is oxygen or imino and the two Z's are the same; PA0 R.sup.3 is alkylene or a group of the formula: ##STR4## wherein R.sup.7 a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.