Photostabilities of Amlodipine OD Tablets in Different Dosage Forms

Abstract

Amlodipine is a dihydropyridine drug that is used to lower high blood pressure. In this study, the photostabilities of orally disintegrating (OD) amlodipine tablets, both original and generic versions, and their powdered and suspended forms were evaluated. The concentration of the active pharmaceutical ingredient (API) was monitored by high-performance liquid chromatography (HPLC), revealing that residual amounts of API in powders and suspensions significantly decreased after ultraviolet light (UV) irradiation for 24 hr. Amlodipine OD tablets and their powders were packaged and stored at a house and a pharmacy for up to 90 days for the evaluation of their photostabilities in clinical use, and that amounts of API in the powdered form significantly decreased when they were stored in the house. ESI-LC/MS/MS analysis was performed to determine the chemical structure of photoproducts generated by photo-irradiated amlodipine OD tablets. It revealed that mainly a dehydrogenated form of amlodipine was generated concomitant with the photodegradation by UV and sunlight irradiation. This is the first study that evaluated the photostabilities of original amlodipine OD medicines, their generic OD versions and their altered forms.

Structure Determination of Felodipine Photoproducts in UV-Irradiated Medicines Using ESI-LC/MS/MS

“…In the MS/MS spectrum, one fragment ion ( m / z 354.00) was detected ( Figure 6 B) and seemed to be generated by the elimination of an ethyl group ( Figure 6 C). It is indicated that the oxidation of a dihydropyridine ring resulted in the decrease in its polarity because FL photoproduct 1 eluted faster than FL as shown in Figure 2 , the same as our previous report [ 3 ]. In addition, a pyridine derivative showed no characteristic absorption among 300 to 400 nm, which differs from FL as shown in Figure 3 B.…”

“…In a clinical situation, there are several cases where tablets are crushed and packaged followed by storage in the houses of patients. Our previous reports also showed that long-term storage (for up to 90 days) of crushed amlodipine oral disintegration tablets in the package near the window of a house, where it is exposed to sunlight irradiation, resulted in a decrease in their APIs [ 3 ]. The decrease in APIs means the weakening of the beneficial effect of a medicine.…”

Evaluation of Photostability of Medicines and Development of the Photostabilization of the Photosensitive Medicines

“…The change of the dosage form of two original amlodipine orally disintegrating (OD) tablets, Amlodin ® OD tablets and Norvasc ® OD tablets, induced the decrease of their photostability as shown in Table 2. Residual amounts of API significantly decreased compared to the control samples when both tablets were UV-irradiated after crushing or suspending [58]. Furthermore, these OD tablets and their powders were packaged and stored in a house and a pharmacy for up to 90 days for the purpose of evaluating their photodegradability.…”

Fibrous Polyimide Stationary Phase for the Separation of Aromatic Compounds in Reversed-Phase Liquid Chromatography

“…In particular, an appropriate choice of stationary phase is quite important [8][9][10][11][12]. Octadecylsilica (ODS) is the most popular stationary phase in reversed-phase (RP) LC owing to its good separation performance for various complex sample mixtures [13][14][15][16][17][18][19]. The chemical structure of ODS comprises chemically-bonded octadecyl groups on the surface of silicagel particles.…”