The origin of Debye-like relaxation in some hydrogen-bonded liquids is a matter of hot debate over the past decade. While a relatively clear picture of the issue has been established for monohydroxy alcohols, the Debye-type dynamics in other glass-forming systems still remains a not fully understood phenomenon. In this paper we present the results of dielectric measurements performed in the frequency interval ${10}^{-1}$ to ${10}^9\mathrm{Hz}$, both in the supercooled and normal liquid state of etoricoxib anti-inflammatory agent. Our investigations reveal the presence of slow Debye-like relaxation with features similar to that found for another active pharmaceutical ingredient, ibuprofen. Our results provide a fresh insight into the molecular nature of Debye-type relaxation in H-bonded pharmaceutically relevant materials and thus may stimulate the academic community for further discussion concerning the molecular dynamics of hydrogen-bonded fluids in general.

• Received 9 June 2015

DOI:https://doi.org/10.1103/PhysRevE.92.022309