The United States Patent and Trade Marks Office (USPTO) has granted Hyderabad-based Aurobindo Pharma a patent No 6458949 for its sterile cephalosporin drug which would enjoy a market size of $1.5 billion. While confirming the report, a company source said that Aurobindo had developed a non-infringing process for the preparation of Ceftiofur, a cephalosporin antibiotic useful in the treatment of bovine respiratory disease using a novel bromo or chloro intermediate.

The process consists of steps of cyclising a new bromo or chloro intermediate with thiourea, a lustrous white crystalline compound, in the presence of selected solvents to produce Ceftiofur of high purity.

The company would file an ANDA through the US-based Cefazone Pharma LLC, USA, a joint venture between Aurobindo and Med Pharmex. The joint venture company makes sterile and oral cephalosporin. Aurobindo is a known leader in the semi-synthetic penicillins (SSPs), cephalosporins, anti-virals and certain life style disease drugs.

Sterile cephalosporins, which involve complex chemistry and are known to have entry barriers, constitute over 15 per cent of the company's revenues.

Though the branded sterile cephalosporin market size is estimated at $1.5 billion, the real benefit would depend on the patents, competition and the number of companies that would foray into the market.