title: Analysis and stability study of retinoids in pharmaceuticals by LC with fluorescence detection.
abstract: Liquid chromatographic (HPLC) methods with fluorescence detection at different wavelengths were developed for measurements of retinoic acids (13-cis and all-trans) in pharmaceutical dosage forms and components of 'retinoid solution' (all-trans retinoic acid, vitamin A palmitate and beta-carotene), a galenical of 'Di Bella therapy', using reversed phase columns under isocratic conditions. The stability of all-trans retinoic acid in cream and all-trans retinoic acid and vitamin A palmitate in 'retinoid solution' was investigated. Solid-phase extraction (SPE), using C18 sorbent was applied to the analysis of retinoic acids (9-cis, 13-cis and all-trans) in the 'retinoid solution' to obtain a practical and reliable sample clean-up. The results showed that these preparations (cream and solution) can be conveniently stored in the dark (t.a. or 2-8 degrees C): under these conditions about 86-87% of the all-trans retinoic acid initial concentration in both formulations and about 73-78% of vitamin A palmitate in the 'retinoid solution' remained after 90 days, while under sunlight exposure rapid degradation of the drugs was observed.
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Università di Bologna, Italy. rgatti@alma.unibo.it
authors.forename: R
authors.initials: R
authors.lastname: Gatti
authors.forename: M G
authors.initials: MG
authors.lastname: Gioia
authors.forename: V
authors.initials: V
authors.lastname: Cavrini
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D015474:Isotretinoin / Q000032:analysis*; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D014212:Tretinoin / Q000032:analysis*
chemical_list: D004364:Pharmaceutical Preparations; D014212:Tretinoin; D015474:Isotretinoin