.

Pharmaceutical Business Intelligence

  • Anticipate P&T budget requirements
  • Evaluate market entry opportunities
  • Find generic sources and suppliers
  • Predict branded drug patent expiration

► Plans and Pricing

Upgrade to enjoy subscriber-only features like email alerts and data export. See the Plans and Pricing

DrugPatentWatch Database Preview

Claims for Patent: 4,092,315

« Back to Dashboard

Claims 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 125.degree. to 160.degree. 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 132.degree. C.
« Back to Dashboard

For more information try a trial or see the database preview and plans and pricing

Drugs may be covered by multiple patents or regulatory protections. All trademarks and applicant names are the property of their respective owners or licensors. Although great care is taken in the proper and correct provision of this service, thinkBiotech LLC does not accept any responsibility for possible consequences of errors or omissions in the provided data. The data presented herein is for information purposes only. There is no warranty that the data contained herein is error free. thinkBiotech performs no independent verifification of facts as provided by public sources nor are attempts made to provide legal or investing advice. Any reliance on data provided herein is done solely at the discretion of the user. Users of this service are advised to seek professional advice and independent confirmation before considering acting on any of the provided information. thinkBiotech LLC reserves the right to amend, extend or withdraw any part or all of the offered service without notice.

`abc