The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 22, 2011
Filed:
Oct. 26, 2005
Eswaraiah Sajja, Hyderabad, IN;
Venkata Naga Kali Vara Prasada Raju Vetukuri, Hyderabad, IN;
Srinivas Reddy Ningam, Medak, IN;
Ravindra Vedantham, Hyderabad, IN;
Rajyalakshmi Bodepudi, Guntur, IN;
Eswaraiah Sajja, Hyderabad, IN;
Venkata Naga Kali Vara Prasada Raju Vetukuri, Hyderabad, IN;
Srinivas Reddy Ningam, Medak, IN;
Ravindra Vedantham, Hyderabad, IN;
Rajyalakshmi Bodepudi, Guntur, IN;
Dr. Reddy's Laboratories Limited, Hyderabad, Andhra Pradesh, IN;
Dr. Reddy's Laboratories, Inc., Bridgewater, NJ (US);
Abstract
A process for preparing crystalline Form A of tadalafil (I), comprising crystallization from a solution of tadalafil in a solvent comprising a C-Cester, a ketone, dimethylformamide, dimethylsulfoxide, ethanol, acetonitrile, a chlorinated hydrocarbon, t-butanol, N,N-dimethylacetamide, dioxane, N-methyl pyrrolidone, or a mixture of any two or more thereof.