Modelling nifedipine photodegradation, photostability and actinometric properties

Ф-order kinetics of photoreversible-drug reactions

“…In addition, the determined overall rate-constants of drug 60 photodegradation reaction could neither be compared to those obtained by other studies or 61 lead to the determination of the photochemical quantum yield of the reaction (the overall 62 rate-constant and the quantum yield are generally achieved by separate experiments). absorb the incident light at a non-isosbestic wavelength (Maafi and Maafi, 2013 …”

“…Sample # The strategy adopted in a previous study (Maafi and Maafi, 2013 Therefore, the elucidation of the true mechanism, for this case, can only be achieved using 405 additional information that might be obtained by alternative means (until a pure 406 spectrokinetic method is developed). …”

Photodegradation of 1, 4-Dihydropyridine Antihypertensive Drugs: An Updated Review

“…In a subsequent work, photodegradation experiments on nifedipine, monitored by DAD analysis, confirmed that the wavelengths responsible of degradation are in the spectral region 280-400 nm. The formation of the pyridine and nitroso photoproducts was confirmed too, obeying a unimolecular mechanism [8]. In this work, a new reaction order (the so-called Φ-order) was identified and proposed for unimolecular photodegradation reactions.…”

“…The DHP drugs exhibit high sensitivity to light, undergoing a photo degradation process consisting, in most of the cases, in the oxidation of the dihydropyridine ring to pyridine derivative, as shown in fig. 1 [8,9].…”

A Non‐Heme Iron Photocatalyst for Light‐Driven Aerobic Oxidation of Methanol

“…Irradiation of 3 at 300 nm resulted in similar changes; however, there was a pronounced wavelength dependence of the photochemical quantum yield26, 27 ( Φ 300 nm =0.31±0.01, Φ 365 or 355 nm =0.07±0.01). Irradiation at 490 nm did not affect the absorption spectrum (see Figure S4) even though this wavelength is in resonance with a weak absorption band.…”