title: Actinometric and Φ-order photodegradation properties of anti-cancer Sunitinib.
abstract: The photodegradation reaction of Sunitinib (SUT), occurring via Z-E photoisomerisation, has been evaluated in this study using the recently developed Φ-order kinetics. In ethanol, the forward (Z → E) photoreaction of SUT was invariant with irradiation (its quantum yield, Φ(E-->Z)(λ)(irr) ≈ 0.019) in contrast to the E → Z isomerisation whose Φ(E-->Z)(λ)(irr) undergoes a 30-fold, sigmoid-shaped, increase with increasing irradiation wavelength. This situation limited usefully the extent of Z-SUT photodegradation at the photostationary state to a maximum of c.a. 30% of the initial concentration. Nevertheless, these results support a strong recommendation for a complete protection of SUT from light at all stages. Furthermore, a SUT-actinometer was developed and was proven to be useful for the 320-480 nm spectral range. The latter wavelength interval defined as well SUT photodegradation causative range. The formalism of Φ-order kinetics proves to be a useful investigative tool for drugs' photodegradation studies.
authors: Leicester School of Pharmacy, De Montfort University, The Gateway, Leicester LE1 9BH, UK. Electronic address: mmaafi@dmu.ac.uk.
authors: Mounir
authors: M
authors: Maafi
authors: Leicester School of Pharmacy, De Montfort University, The Gateway, Leicester LE1 9BH, UK.
authors: Lok Yan
authors: LY
authors: Lee
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000528:radiation effects*; D004355:Drug Stability; D000431:Ethanol / Q000737:chemistry; D007211:Indoles / Q000737:chemistry / Q000528:radiation effects*; D007536:Isomerism; D007700:Kinetics; D008027:Light; D008956:Models, Chemical; D010782:Photolysis; D047428:Protein Kinase Inhibitors / Q000737:chemistry / Q000528:radiation effects*; D011758:Pyrroles / Q000737:chemistry / Q000528:radiation effects*; D000077210:Sunitinib
chemical_list: D000970:Antineoplastic Agents; D007211:Indoles; D047428:Protein Kinase Inhibitors; D011758:Pyrroles; D000431:Ethanol; D000077210:Sunitinib
keywords: Actinometry; Photodegradation; Photoisomerism; Quantum yield; Sunitinib