Title:
THE PROCESS OF MANUFACTURING PHARMACEUTICAL GRADE TANNATES
Document Type and Number:
WIPO Patent Application WO2002005745
Kind Code:
A3
Abstract:
Antihistamines are available in the form of free bases as well as salts i.e. hydrocholoride, maleate, tannate, etc. Frequently, it is necessary to utilise antihistamines in the form of tannate salt because such salts are generally quite stable and may be administered in such from without untoward side effects. Tannic acid, also known as tannin, is a well known naturally occurring substance. Tannic acid, which is available commercially, usually contain about 5 % of water, has a molecular weight of about 1700 and is typically produced from Turkish or Chinese nutgall. Antihistamine tannates, presently manufactured commercially, are relatively impure. Such tannates are prepared by the reaction of antihistamine free base with tannic acid and using a volatile solvent, isopropanol (IPA). The yield is only fair (around 70 %) and decomposition products e.g. 2-5 % along with significant amount of volatile solvent, isopropanol (6-10 %) remains with the product, which cannot be removed. According to present invention, isopropanol is removed by using a solvent for isopropanol which I highly volatile, which does not dissolve tannates but disperses the wet cake of tannate. The solvent, hexane, is added to wet cake while stirring it and the it is filtered. This results in residue of tannates with lower isopropanol content. The drying results into pharmaceutical grade tannate.
Inventors:
KHAMAR BAKULESH MAFATLAL (IN)
SRINIVASAN CHIDAMBARAM VENKATE (IN)
MURALIDNAR KOMPALY (IN)
MITRA JYATI (IN)
REDDY MAMILLA SRINIVAS (IN)
SOMANNAWAR YALLAPPA SOMANNA (IN)
SRINIVASAN CHIDAMBARAM VENKATE (IN)
MURALIDNAR KOMPALY (IN)
MITRA JYATI (IN)
REDDY MAMILLA SRINIVAS (IN)
SOMANNAWAR YALLAPPA SOMANNA (IN)
Application Number:
PCT/IB2001/001250
Publication Date:
October 10, 2002
Filing Date:
July 13, 2001
Export Citation:
Assignee:
CADILA PHARMACEUTICALS LTD (IN)
KHAMAR BAKULESH MAFATLAL (IN)
SRINIVASAN CHIDAMBARAM VENKATE (IN)
MURALIDNAR KOMPALY (IN)
MITRA JYATI (IN)
REDDY MAMILLA SRINIVAS (IN)
SOMANNAWAR YALLAPPA SOMANNA (IN)
KHAMAR BAKULESH MAFATLAL (IN)
SRINIVASAN CHIDAMBARAM VENKATE (IN)
MURALIDNAR KOMPALY (IN)
MITRA JYATI (IN)
REDDY MAMILLA SRINIVAS (IN)
SOMANNAWAR YALLAPPA SOMANNA (IN)
International Classes:
C07C215/30; C07C215/60; C07C217/08; C07C217/10; C07C217/18; (IPC1-7): A01N25/00; C07C69/88
Foreign References:
| US3282789A | 1966-11-01 | |||
| US5599846A | 1997-02-04 | |||
| US5663415A | 1997-09-02 |
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