.

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: 6,107,302

« Back to Dashboard

Claims for Patent: 6,107,302

Title: Guanine derivative
Abstract:The invention relates to an anhydrous crystalline form of (2-[2-amino-1,6-dihydro-6-oxo-purin-9-yl)methoxy]ethyl L-valinate hydrochloride (otherwise known as valaciclovir hydrochloride) and a process for preparing it.
Inventor(s): Carter; Barry Howard (Kinston, NC), Partin; Jane Muse (Raleigh, NC), Varlashkin; Peter Gregory (Clayton, NC), Winnike; Richard Augustus (Durham, NC), Grubb, III; William Bayne (Athens, GA), Conway; Gregory Alan (Greenville, SC), Lake; Philip George (Dartford, GB), Skinner; David Michael (Dartford, GB), Whatrup; David James (Dartford, GB)
Assignee: Glaxo Wellcome Inc. (Research Triangle Park, NC)
Application Number:08/875,173
Patent Claims: 1. Storage stable Valaciclovir hydrochloride in anhydrous crystalline form and being essentially free of water of hydration including the following d spacing pattern (in Angstroms): 10.20.+-.0.08, 8.10.+-.0.06, 7.27.+-.0.06, 6.08.+-.0.05, 5.83.+-.0.03, 5.37.+-.0.02, 5.23.+-.0.02, 4.89.+-.0.02, 4.42.+-.0.02, 4.06.+-.0.02, 3.71.+-.0.02, 3.39.+-.0.02, 3.32.+-.0.02, 2.91.+-.0.02, 2.77.+-.0.02.

2. Crystalline valaciclovir hydrochloride as claimed in claim 1 having a water of hydration content of not more than 3% w/w.

3. Crystalline valaciclovir hydrochloride as claimed in claim 2 having a water of hydration content of not more than 2% w/w.

4. Crystalline valaciclovir hydrochloride as claimed in claim 3 having a water of hydration content of riot more than 1% w/w.

5. A method for the treatment of herpes viral infection in a human which comprises administering to the human host, an effective anti-herpes viral amount of storage stable valaciclovir hydrochloride in anhydrous crystalline form and being essentially free of water of hydration as claimed in claim 1.

6. A process for the production of storage stable valaciclovir hydrochloride in anhydrous crystalline form and being essentially free of water of hydration including the d spacings as defined in claim 1, said process comprising treating valaciclovir hydrochloride with an amount of 15% to 40% w/w lower alcohol having 1 to 4 carbon atoms or a lower ketone containing from 3 to 6 carbon atoms serving to convert an amount of said valaciclovir hydrochloride into said anhydrous crystalline form; and then isolating said anhydrous crystalline form.

7. A process for the production of storage stable valaciclovir hydrochloride in an anhydrous crystalline form and being essentially free of water of hydration including the d spacings as defined in claim 1, said process comprising the steps of:

a) forming valaciclovir in solution either in free base or salt form;

b) converting said free base valaciclovir or salt thereof to valaciclovir hydrochloride;

c) isolating valaciclovir hydrochloride from the solution and optionally removing unbound solvent leaving the valaciclovir hydrochloride in substantially dry form;

d) treating valaciclovir hydrochloride with 15% to 40% w/w of a lower alcohol having 1 to 4 carbon atoms or a lower ketone containing from 3 to 6 carbon atoms serving to convert an amount of said optionally dried valaciclovir hydrochloride into said anhydrous crystalline form; and

e) isolating said anhydrous crystalline form.

8. A process as claimed in claim 7 wherein the lower alcohol is ethanol or a solvent composed substantially of ethanol.

9. A process as claimed in claim 8 wherein the lower alcohol is ethanol or a solvent composed substantially of ethanol and is added in a range of about 17% by weight to about 40% by weight of substantially dry valaciclovir hydrochloride.
« 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