A simple alternative to prodrug: The hydrochloride salt monohydrate of the prostate anticancer drug abiraterone

Publication date: Available online 21 April 2019Source: Journal of Molecular StructureAuthor(s): Rafael G. Silveira, Beatriz N. Cunha, Juan C. Tenório, Deborah Victória Alves de Aguiar, Patricia da Cruz Souza, Boniek Gontijo Vaz, Javier Ellena, Alzir A. Batista, Felipe Terra MartinsAbstractAbiraterone acetate is a first choice prodrug to treat prostate cancer. New higher-solubility multicomponent crystal forms of the active compound abiraterone could substitute for the commonly used acetate prodrug. Here we prepare abiraterone hydrochloride monohydrate, which is the first multicomponent crystal form of this striking prostate anticancer agent. Its solid state characterization by single-crystal X-ray diffraction (SCXRD), infrared (IR) spectroscopy and thermogravimetry (TG) was performed. The only conformational difference in the molecular backbone common to the literature related crystal forms (abiraterone acetate and the free base abiraterone) and our salt resides in the 3-pyridil rotation upon protonation. If the neutral molecules found in the two literature structures are taken as references, this motif is rotated by almost exactly 180° in our protonated abiraterone. Crystal packing also follows the protonation pattern. While in both prodrug and free base there is formation of head-to-tail fashioned one-dimensional chains as the main supramolecular entities, hydrogen bonded sheets are the main supramolecular motifs of abiraterone hydrochloride monohydrate. In addition, th...
Source: Journal of Molecular Structure - Category: Molecular Biology Source Type: research