Physicochemical Properties of a Phenyltetrahydroquinolinedione Derivative with TRPA1 Antagonist Activity

A new active pharmaceutical ingredient (API) with TRPA1-antagonist activity (phenyltetrahydroquinolinedione derivative) was a white or almost white finely crystalline non-hygroscopic powder consisting of spherical particles with a large surface area: D 90 and span were 22.2 μm and 1.9 units, respectively. The substance was sparingly soluble in EtOH (96%) and almost insoluble in H 2 O and n -hexane, melted at 203.5 – 208.3°C with decomposition, lost 0.11% of its mass upon drying, and contained 0.096% H 2 O and 99.3% API. The obtained data imposed certain restrictions on development of a dosage form of the substance under consideration, established requirements for production strategies of the corresponding dosage forms, and could also be used for justification of the draft specification of the API.