Sulfonated precursors of thymidine for the treatment of epithelial hyperplasias
This invention relates to pharmaceutical compositions comprising a sulfonated biological precursor of thymidine, such as a precursor of 4-thiothymidine (4-TT), and their use in the photodynamic treatment of skin hyperplasias, including cancer, psoriasis, actinic keratosis and keloids, by topical or systemic administration.
1. A pharmaceutical composition comprising a sulfonated de novo synthesis precursor of thymidine and a carrier, wherein the sulfonated de novo synthesis precursor of thymidine is a precursor of 4-thiothymidine.
2. The composition according to claim 1 , wherein the sulfonated de novo synthesis precursor of 4-thiothymidine is selected from the group consisting of 4-thioorotate, 4-thiodihydroorotate, 4-thiomidylate, and carbamoyl-thioaspartate.
3. The composition according to claim 2 , wherein the sulfonated de novo synthesis precursor is further derivatised at the 6 carboxylic position into an ester by reaction with an alcohol.
4. The composition according to claim 3 , wherein the alcohol is a compound designed to facilitate penetration of skin and cell membranes.
5. The composition according to claim 1 , wherein the composition is formulated for topical administration.
6. The composition according to claim 5 further contains a penetration enhancer.
7. The composition according to claim 6 , wherein the penetration enhancer is an alcohol.
8. The composition according to claim 6 , wherein the penetration enhancer is a hydroxylated polymer.
9. The composition according to claim 8 , wherein the hydroxylated polymer is polyethylene glycol or polypropylene glycol.
10. The composition according to claim 6 , wherein the penetration enhancer is a natural microfibrillated polysaccharide.
11. The composition according to claim 10 , wherein the natural microfibrillated polysaccharide is selected from the group consisting of microfibrillated cellulose, microfibrillated starch, microfibrillated dextran and cyclodextrins.
12. The composition according to claim 6 , wherein the penetration enhancer is a sulfoxide.
13. The composition according to claim 12 , wherein the sulfoxide is selected from the group consisting of dimethylsulfoxide, decylmethylsulfoxide and dimethylsulfoacetamide.
14. The composition according claim 1 , further comprising a pharmaceutically acceptable carrier.