Crystal form of doxofylline and preparation method of crystal form of doxofylline

Abstract

The invention discloses a crystal form of doxofylline. The crystal form shows characteristic peaks at 8.60 + / -0.1 degrees, 11.31 + / -0.1 degrees, 15.02 + / -0.1 degrees, 16.91 + / -0.1 degrees, 17.32 + / -0.1 degrees and 18.63 + / -0.1 degrees according to an X-ray diffraction spectrum expressed by a 2 theta angle; the differential scanning calorimetry determines that an absorption single peak exists at 143.3 DEG C, and the crystal form is formed by recrystallizing doxofylline with a mixed solvent of methylbenzene, absolute ethyl alcohol and water. The invention provides a novel crystal form of doxofylline, the novel crystal form has high water solubility, the API purity can reach 99% or above and is close to 100%, almost no impurity is detected, and the novel crystal form is suitable for injectiondosage forms.

Description

technical field

[0001] The invention relates to the technical field of drug synthesis, in particular to a crystal form of doxofylline and a preparation method thereof. Background technique

[0002] Doxofylline (Doxofylline), the chemical name is 7-[(1,3-dioxol-2-yl)methyl]-1,3-dimethyl-3,7-dihydro-lH- Purine-2,6-dione, its structural formula is shown in formula 1. Doxofylline was launched in Italy in 1988 under the trade name Ansimar. Doxofylline has a strong anti-asthma effect and is a new drug for dilating the bronchi. It is suitable for chronic obstructive pulmonary disease (COPD), bronchial asthma, chronic asthmatic bronchitis and other dyspnea caused by bronchospasm.

[0003]

[0004] When the crystal form of the drug is different, its physicochemical properties will change significantly. Because the dosage form of doxofylline is mainly injection, and the solubility of doxofylline in water is not high, according to the Chinese Pharmacopoeia, doxofylline belongs to...

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