Unilife Corporation (NASDAQ: UNIS) shares zoomed 12.9% to $4.20, on word the company’s CEO plans to buy back up to $1 million in shares this week. Volume for the stock totaled 232,000 shares, lagging an all-day average of 258,000.

A news release out Wednesday announced that Unilife’s CEO, Alan Shortall, intends to purchase $500,000 in shares of the company’s common stock over the next week. Shortall intends to begin purchasing these shares this week at market prices within 48 hours.

Furthermore, Mr. Shortall has advised the Board of Directors of Unilife that he intends to purchase up to an additional U.S. $500,000 of the Company’s common stock between now and September 30, 2011. Mr. Shortall intends to provide twenty-four hours advance notice to U.S. markets before purchasing these additional Unilife shares.

Shortall is the largest shareholder in Unilife. These upcoming purchases by Shortall follow his most recent open market purchases of more than U.S. $500,000 in Unilife shares, which were completed in mid-March 2011 at an average price equivalent to $4.80 per share of common stock.

Shortall was quoted in the release as saying, “I believe that this is an excellent time to purchase shares in Unilife, and to further align my own personal interests to that of my fellow shareholders. In my opinion, Unilife has never had a brighter business future than what we see today. We remain on track with our strategic plan to become a global leader in advanced drug delivery systems. As such, I intend to increase my personal investment in the Company.”

Unilife Corporation is a U.S.-based developer, manufacturer and supplier of advanced drug delivery systems with state-of-the-art facilities in York, Pennsylvania.