Degradation rates and products of fluticasone propionate in alkaline solutions

[Formulation Studies and Application of Their Experimental Techniques to Drug Discoveries]

In my first experience as a researcher, I isolated and performed structural predictions of the novel compounds, cis- and trans-palythenic acids, from Noctiluca milialis. I then worked for a pharmaceutical company in a research laboratory of pharmaceutics. I examined an inclusion complex of cinnarizine with β-cyclodextrin, and found that the inclusion complex did not improve the oral bioavailability of cinnarizine. However, the bioavailability of the inclusion complex after its oral administration was improved by a competing agent. This was the first study to show the potential of a competing agent to improve bioavailability. I subsequently joined a laboratory performing drug discovery research and used experimental techniques from pre-formulation studies. A screening system of solubility for drug design and discovery was constructed to increase the solubilities of compounds synthesized in the laboratory. This screening system contributed to the discovery of a phosphodiesterase type 5 inhibitor with sufficient solubility. As a visiting lecturer at a university, I prepared amoxicillin intragastric buoyant sustained-release tablets for the eradication of Helicobacter pylori and applied cinnarizine as a competing agent. I established a laboratory of pharmaceutics at a university in Tochigi. To develop an enema with fluticasone propionate for ulcerative colitis, I investigated its physicochemical properties and methods to improve its solubility. After moving to another university in Kagawa, I developed a method to reduce the amount of drugs remaining on the surfaces of a pestle and mortar following the grinding of tablets, and new cleaning agents for an automatic dividing packaging machine were discovered.

Identification and Characterization of Herbicide Penoxsulam Transformation Products in Aqueous Media by UPLC-QTOF-MS

Photodegradation is an important non-biodegradation process of pesticide degradation in aquatic environments. In this study, the effect of different forms of nitrogen on the photodegradation kinetics of penoxsulam was investigated. The photodegradation of penoxsulam was accelerated by NO^3- and NO^2- but was not affected by NH⁴⁺. Ultra-high-performance liquid chromatography coupled with time-of-flight mass spectrometry was used to separate and identify the transformation products (TPs)converted by photodegradation of penoxsulam in an aqueous solution under UV-Vis (290-800 nm) irradiation. Seven major transformation products were identified based on mass spectral data. The structure was determined by elemental composition calculations, comparison of structural analogs, and existing literature. The main pathways of photodegradation were found to be sulfonamide bond cleavage, rearrangement, triazole ring cleavage, and hydroxylation. These findings are critical to elucidate the environmental fate of penoxsulam in aquatic ecosystems and provide a basis for further environmental risk assessment.