Photodegradation studies on lacidipine in solution: basic experiments with a cis-trans reversible photoequilibrium under UV-A radiation exposure.
The photostability of Lacidipine, a dihydropyridine drug used in the treatment of mild and moderate hypertension, was studied in solutions exposed to UV-A radiations. The effects of the solvent (ethanol, acetone, dichloromethane), drug concentration and radiation wavelength on the drug photostability were evaluated. Lacidipine and its photoproducts were separated by a selective liquid chromatographic (HPLC) method, under normal phase conditions (CN-column), using n-hexane:ethanol 97:3 (v/v) as mobile phase, at a flow rate of 2.0 ml/min. The main photodegradation products were isolated and characterised and a photodegradation pathway was proposed for Lacidipine in solution. The cis-isomer and a photocyclic isomer proved to be the main photodegradation products.
De Filippis
P
P
Glaxo Wellcome S.p.A., GlaxoSmithkline Group, Medicines Research Centre, via A. Fleming 4, 37135, Verona, Italy.
Bovina
E
E
Da Ros
L
L
Fiori
J
J
Cavrini
V
V
D002121:Calcium Channel Blockers / Q000032:analysis / Q000737:chemistry / Q000528:radiation effects*; D004095:Dihydropyridines / Q000032:analysis / Q000737:chemistry / Q000528:radiation effects*; D004355:Drug Stability; D019999:Pharmaceutical Solutions / Q000737:chemistry / Q000528:radiation effects; D010777:Photochemistry; D014466:Ultraviolet Rays / Q000009:adverse effects
D002121:Calcium Channel Blockers; D004095:Dihydropyridines; D019999:Pharmaceutical Solutions; C060285:lacidipine