(Corrects to clarify that certain batches of the drug are being withdrawn, and not the drug)
* Says white particulate matter in some Dyloject vials
* Drug awaiting FDA approval in United States
* Shares down as much as 30 pct
May 24 (Reuters) - Javelin Pharmaceuticals Inc JAV.A said the UK unit of Therabel Pharma NV, which owns commercial rights to Javelin's post-operative pain drug Dyloject in the European Union, was withdrawing certain batches of the injectable drug from the UK market.
Shares of Javelin fell as much as 30 percent to $1.39 on the American Stock Exchange, before paring some losses to trade down 18 percent at $1.45.
Therabel Pharma UK Limited became aware of the presence of a white particulate matter in some vials of Dyloject in its supply chain and reported the matter to regulators in the UK, Javelin said in a statement.
Dyloject, which is awaiting U.S. Food and Drug Administration approval, has been marketed in the UK since December 2007, the company said.
Reporting by Shailesh Kuber in Bangalore; Editing by Aradhana Aravindan