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Generated: March 21, 2018

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Claims for Patent: 4,092,315

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Summary for Patent: 4,092,315
Title: Novel crystalline forms of prazosin hydrochloride
Abstract:The invention relates to novel and valuable crystalline forms of the hypotensive agent prazosin hydrochloride. The anhydrous .alpha.-form is preferred because it is relatively non-hygroscopic and hence possesses important advantages in handling and formulation. The polyhydrate form of prazosin hydrochloride is preferred because of its low, uniform rate of dissolution.
Inventor(s): Bianco; Ernest J. (Niantic, CT)
Assignee: Pfizer Inc. (New York, NY)
Application Number:05/662,937
Patent Claims: 1. The crystalline .alpha.-form of 2-[4-(2-furoyl)piperazin-1-yl]-4-amino-6,7-dimethoxyquinazoline hydrochloride characterized by the infrared spectrum in potassium bromide having the following absorption bands:

2. The process for preparing the crystalline .alpha.-form of 2-[4-(2-furoyl)piperazin-1-yl]-4-amino-6,7-dimethoxyquinazoline hydrochloride of claim 1 which comprises precipitation of said .alpha.-form after heating 2-[4-(2-furoyl)piperazin-1-yl]-4-amino-6,7-dimethoxyquinazoline hydrochloride, a hydrate or methanolate thereof, in the presence of an alkanol or cycloalkanol solvent having from about 5 to 7 carbon atoms at a temperature in the range of about to C., until formation of said crystalline .alpha.-form is substantially complete.

3. The process of claim 2 whrein said alcoholic solvent is isoamyl alcohol.

4. The process of claim 3 wherein said isoamyl alcohol is heated at a temperature of about C.

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Serving hundreds of leading biopharmaceutical companies globally:

Johnson and Johnson
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Boehringer Ingelheim

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