Crystal Habits and Biological Properties of N-(4-Trifluoromethylphenyl)-4-Hydroxy-2,2-Dioxo-1H-2λ6,1-Benzothiazine-3-Carboxamide

Autor: Lyudmila V. Sidorenko, Igor V. Ukrainets, Svitlana V. Shishkina, L. A. Petrushova, Andrii I. Fedosov, Natali I. Voloshchuk, Galina Sim, Pavlo S. Bondarenko
Rok vydání: 2019
Předmět:
Zdroj: Scientia Pharmaceutica
Volume 88
Issue 1
ISSN: 2218-0532
DOI: 10.3390/scipharm88010001
Popis: In order to study polymorphic modifications of N-(4-trifluoromethylphenyl)-4-hydroxy-2,2-dioxo-1H-2&lambda
6,1-benzothiazine-3-carboxamide, which is of interest as a promising analgesic, its three colorless crystal forms with different habitus have been obtained: sticks of ethyl acetate, plates of meta-xylene and blocks of ortho-xylene. However, the X-ray diffraction analysis has shown that all the forms studied have the identical molecular and crystal structure in spite of such significant differences in appearance. Moreover, pharmacological tests have revealed significant differences in the analgesic activity in these samples (a total of five experimental models were used: &ldquo
acetic-acid-induced writhing&rdquo
&ldquo
hot plate&rdquo
thermal irritation of the tail tip&rdquo
(tail-flick), &ldquo
tail electric stimulation&rdquo
and &ldquo
neuropathic pain&rdquo
), acute toxicity and the ability to cause gastric damage. As a result, only the plate crystal form of N-(4-trifluoromethylphenyl)-4-hydroxy-2,2-dioxo-1H-2&lambda
6,1-benzothiazine-3-carboxamide is recommended for further studies. Thus, it has been proven that the habitus of crystals is an important characteristic of the drug substance and is able to have a noticeable effect on its biological properties. Changes in habitus should be considered as a guide to the mandatory verification of at least the basic pharmacological parameters of the new form regardless of whether the molecular and crystal structure changes.
Databáze: OpenAIRE