Instrumental investigations of promestriene: first report regarding the solid-state characterization and compatibility with pharmaceutical excipients

In this paper, ten samples containing promestriene (PRMS) were investigated, namely the pure active pharmaceutical ingredient (API) and nine binary mixtures prepared with commonly used excipients in solid pharmaceutical formulations. The necessity of such study is represented by the fact that the physicochemical screening of PRMS is not reported in the literature. Also, as convergent arguments for the necessity of this study, it can be mentioned that on Romanian pharmaceutical market, promestriene containing formulations are no longer commercialized since 2015, creating health problems to a large category of patients. As such, this study can serve as a starting point for the adequate selection of ingredients used in magistral preparations, with increased stability and bioavailability. The study revealed that PRMS is compatible with all of the selected excipients, namely methyl 2-hydroxyethyl cellulose (tylose), methyl cellulose (MethocelTM), starch, mannitol, magnesium stearate, magnesium citrate, Talc, colloidal SiO 2 (aerosil) and polyvinylpyrrolidone K-30 (PVPK30), as confirmed by universal attenuated total reflectance Fourier transform infrared (UATR-FTIR) spectroscopy, powder X-ray diffraction patterns and thermal analysis.