The structure of osimertinib was in

The structure of osimertinib was inferred from the route of synthesis and confirmed by 1H and 13C NMR spectroscopy, IR spectroscopy, UV spectroscopy, mass spectrometry and elemental analysis.The active substance is a non-hygroscopic crystalline solid with pH dependent aqueous solubility: slightly soluble at pH 1.2, sparingly soluble in pH 4.5 buffer and very slightly soluble in pH 7 buffer. These properties are adequate for an oral solid dosage form. Only one polymorphic form is known despite extensive polymorph screening. Osimertinib is achiral.Osimertinib is considered a new active substance from a quality perspective. The applicant compared its structure with active substances within authorised products in the EU and demonstrated that it is not a salt, ester, ether, isomer, mixtures of isomers, complex or derivative (e.g. pro-drug or metabolite) of any of them