title: Photostabilization studies of antihypertensive 1,4-dihydropyridines using polymeric containers.
abstract: 1,4-dihydropyridine antihypertensives (DHPs) are almost all dispensed in solid pharmaceutical formulations for their easy lability when exposed to light. This paper reports a study on the photoprotective effect of containers in different glassy or polymeric matrices with regard to four known DHPs when in solutions. The samples were subjected to forced degradation by means of a Xenon lamp, in accordance with the international rules on drug stability evaluation. The simultaneous determination of the drugs and their photoproducts was carried out by applying the multivariate curve resolution (MCR) methodology to the spectral data recorded along the irradiation test. This technique was able to determine the kinetic parameters and resolve the spectra of the photoproducts. The time required to reduce by 10% the concentration of the drug (t0.1) was adopted as a criterion to compare the protective ability of the containers. A significant photoprotection for all drugs tested was obtained by the use of polyethylene terephthalate (PET) containers. The best result was achieved for the felodipine solution in blue PET transparent bottle of 0.6mm thickness, reaching an almost complete stabilization up to six hours under stressing irradiation. In contrast, the glass containers, whether or not coloured, did not provide a satisfactory photoprotection of the drugs, showing in any case t0.1 values under 24min. These results can be a good opportunity to design new photoprotective pharmaceutical packaging for DHPs in liquid dosage form.
authors.affiliation: Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: De Luca
authors.affiliation: Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Ioele
authors.affiliation: Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Spatari
authors.affiliation: Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy. Electronic address: gaetano.ragno@unical.it.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Ragno
mesh_terms: D000959:Antihypertensive Agents / Q000737:chemistry*; D004095:Dihydropyridines / Q000737:chemistry*; D004349:Drug Packaging; D004355:Drug Stability; D004356:Drug Storage; D015736:Felodipine / Q000737:chemistry; D005898:Glass; D008027:Light; D019999:Pharmaceutical Solutions; D010782:Photolysis; D011093:Polyethylene Terephthalates / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D013997:Time Factors
chemical_list: D000959:Antihypertensive Agents; D004095:Dihydropyridines; D019999:Pharmaceutical Solutions; D011093:Polyethylene Terephthalates; D011108:Polymers; C038806:1,4-dihydropyridine; D015736:Felodipine
keywords: Dihydropyridines; Felodipine; Felodipine (PubChem CID: 3333); Lercanidipine (PubChem CID: 65866); MCR analysis; Nifedipine (PubChem CID: 4485); Nimodipine (PubChem CID: 4497); PET containers; Photodegradation; Photostabilization