Change of the dosage form of the medicine is a useful method for the improvement of the medicine-taking compliance. However, the photostability of the medicine may be decreased on account of the change of the dosage form, followed by the change of the quality of it. On the other hand, there is few information focused on the photostability of the dosage-changed medicine. In this study, the effects of the change of the dosage form on the photostability of some non-steroidal anti-inflammatory drugs (NSAIDs) are investigated. Photo-exposure by means of the black light, containing ultraviolet (UV) at mainly 365 nm, induced the change of the color of naproxen tablets although the content of the active compound monitored by the high-performance liquid chromatography (HPLC) was not changed. However, the change of the dosage form of naproxen tablets to the powder and the suspension induced the change of the photostability followed by the decrease of the content of the active compound and the generation of two photoproducts. By means of the nuclear magnetic resonance (NMR) analysis, structures of two naproxen photoproducts were determined as 2-acetyl-6-methoxy-naphthalene and 1-(6-methoxy-2-naphthyl) ethanol. This is the first report evaluated the generation of naproxen photoproducts induced by the long-wavelength UV irradiation in the formulation.

Shrimp is a causative food that elicits food-dependent exercise-induced anaphylaxis (FDEIA). In this study, we sought to identify IgE-binding allergens in patients with shrimp-FDEIA. Sera were obtained from eight patients with shrimp-FDEIA and two healthy control subjects. Proteins were extracted from four shrimp species by homogenization in Tris buffer. Immunoblot analysis revealed that IgE from patient sera bound strongly to a 70-kDa and a 43-kDa protein in a preparation of Tris-soluble extracts from Litopenaeus vannamei. Mass spectrometry identified the 70-kDa and 43-kDa proteins as a P75 homologue and fructose 1,6-bisphosphate aldolase (FBPA), respectively. To confirm that the putative shrimp allergens were specifically recognized by serum IgE from shrimp-FDEIA patients, the two proteins were purified by ammonium sulfate precipitation followed by reversed-phase HPLC and/or anion-exchange hydrophobic interaction chromatography and then subjected to immunoblot analysis. Purified P75 homologue and FBPA were positively bound by serum IgE from one and three, respectively, of the eight patients with shrimp-FDEIA, but not by sera from control subjects. Thus, P75 homologue and FBPA are identified as IgE-binding allergens for shrimp-FDEIA. These findings could be useful for the development of diagnostic tools and desensitization therapy for shrimp-FDEIA patients.

A photostabilization strategy is an important aspect of quality assurance for photosensitive compounds. This study focused on the photoprotective effects of selected antioxidants including the effect of L-ascorbic acid (AA) on naproxen (NX) photodegradation in aqueous media. NX degradation during ultraviolet light (UV) irradiation and the protective effects of selected antioxidants were monitored by high-performance liquid chromatography (HPLC). The addition of AA induced the suppression of NX photodegradation, although the protective effect disappeared after AA was degraded completely. The results of the evaluations on the photoprotective effects on NX photodegradation and antioxidative activities of AA and other antioxidants showed that the protective effects of antioxidants are dependent on reducing power and photostability under UV irradiation. In this experiment, quercetin (QU) is the most effective antioxidant on account of the residual rate of QU after UV irradiation and the antioxidative activity in the potential antioxidant (PAO) test was significantly higher compared to other antioxidants following the higher protective effect on NX photodegradation.

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Photodegradation of sulindac (SL), which is clinically used as an anti-inflammatory, analgesic and antipyretic drug in an aqueous media under the ultraviolet (UV) irradiation was investigated. Degradation of SL and the generation of the photoproduct were monitored by means of high-performance liquid chromatography (HPLC). Residual amount of SL was decreased after UV-A,-B and-C irradiation with the generation of the photoproduct, but kinetics of degradation of SL and generation of the photoproduct seems to reach the equilibrium under only the UV-A irradiation. Based on the nuclear overhauser effect spectroscopy (NOESY) coupling pattern in nuclear magnetic resonance (NMR) spectrum and fragmentation pattern in electrospray ionization time-of-flight mass spectrometry (ESI-TOF/MS/MS), the photoproduct was identified as the trans-isomer of SL and the main pathway of SL photo-conversion was photoisomerization by the UV-A irradiation. Monitoring the degradation of SL and its photoproduct by the UV irradiation indicated that photochemical reaction of SL induced by the UV-A irradiation, which is photoisomerization, is different from that of induced by the UV-B or the UV-C irradiation, which is probably further degradation but there was no identification that a further photoproduct was generated from the initially formed photoproduct in the result of HPLC analysis. This is the first study showing the photoisomerization of SL induced by the UV irradiation in the aqueous media.