| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 26646 | Journal of Photochemistry and Photobiology A: Chemistry | 2013 | 9 Pages |
Photodegradation of rosuvastatin calcium (1) under several radiation wavelengths in solid state and solution in solvents of different polarity has been studied. It was shown that 1 is very sensitive, especially in solution, even to low energy wavelengths and main and almost exclusive degradation pathway includes formation of diastereomeric dihydrophenanthrene derivatives (R,S,R)-2 and (S,S,R)-2. Absolute configurations of isolated diastereomeric photoproducts in forms of respective lactones 3 and 4 have been determined. First partial diastereoselective photocyclization of 1 leading 10.5% d.e. of (R,S,R)-2 over (S,S,R)-2 has been determined in water as a solvent. To prevent photodegradation of 1 in solution use of brown glass is necessary. Solid formulations of 1 are efficiently protected against photodegradation by the presence of combination of dyes such as yellow iron oxide and pink color E122 or β-carotene inside the formulation or tablet coating.
► Photodegradation of rosuvastatin calcium in solution and solid state. ► First diastereoselective photocyclization of rosuvastatin to corresponding dihydrophenanthrenes in water as reaction media. ► Determination of absolute configuration of dihydrophenanthrene photoproducts. ► Efficient photoprotection of rosuvastatin calcium formulation by certain colored additives.
