(Reuters) - AcelRx Pharmaceuticals said the U.S. patent office granted two patents on the specialty pharmaceutical company's methods for managing post-operative pain.

AcelRx said the notice of allowance from the U.S. Patent and Trademark Office could provide protection to its NanoTab technology for delivering a pain drug, sufentanil, till at least Feb, 2029.

A Notice of Allowance is issued after the USPTO decides that a patent can be granted after a company has applied for one.

AcelRx's shares closed at $3.40 on Tuesday on the Nasdaq.

(Reporting by Balaji Sridharan in Bangalore; Editing by Saumyadeb Chakrabarty)