Claims
- 1. A method for preparing dexchlor tannate which comprises reacting dexchlorpheniramine free base with tannic acid at a temperature of about 75 to about 150° C. in the presence of 0 to about 20 wt. % water and thereafter recovering the resultant dexchlor tannate.
- 2. The method of claim 1 wherein the reaction is carried out at a temperature of 80 to 130° C.
- 3. The method of claim 1 wherein the reaction is carried out in the presence of 0 to 10 wt. % water.
- 4. The method of claim 1 wherein the dexchlorpheniramine free base is employed in an amount of about 4 to about 8 moles of the free base per mole of tannic acid.
- 5. The method of claim 4 wherein the dexchlorpheniramine free base is employed in an amount of 5 to 6 moles of the free base per mole of tannic acid.
- 6. The method of claim 1 wherein the resultant dexchlor tannate is dried under vacuum at a temperature of about 65 to about 75° C. for a period of 1 to 10 hours or more.
- 7. The method of claim 1 wherein the resultant dexchlor tannate is dried by sparging with nitrogen for a period of 1 to 10 hours or more.
- 8. The method of claim 1 wherein the resultant dexchlor tannate is milled to provide a free-flowing powder.
- 9. The method of claim 8 wherein the powder has a particle size in the range of about 50 to about 200 mesh.
- 10. The method of claim 1 wherein the dexchlorpheniramine free base is obtained by reacting a dexchlorpheniramine salt with the stoichiometric amount of a base.
- 11. The method of claim 10 wherein the dexchlorpheniramine salt comprises dexchlorpheniramine maleate.
- 12. The method of claim 10 wherein the base comprises aqueous sodium hydroxide.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of application Ser. No. 10/206,520 filed Jul. 27, 2002 that in turn is a continuation-in-part of application Ser. No. 10/017,130 filed Dec. 14, 2001.
Continuation in Parts (2)
|
Number |
Date |
Country |
Parent |
10206520 |
Jul 2002 |
US |
Child |
10641533 |
Aug 2003 |
US |
Parent |
10017130 |
Dec 2001 |
US |
Child |
10206520 |
Jul 2002 |
US |