Johnson & Johnson, the world’s biggest maker of health care products, plans to buy back up to $5 billion of the company’s common stock.

The maker of prescription drugs, medical devices and Tylenol said Monday that its board of directors had approved the stock buyback program. The program has no time limit and could be discontinued at any time, the company said it a statement.

Johnson & Johnson’s shares have risen strongly over the past two years, from about $68 to a July 7 all-time closing high of $106.47. They ended Monday down 53 cents to $101.27 and were up 75 cents at $102.02 in after-market trading following the announcement of the buyback program.

J&J, based in New Brunswick, New Jersey, said it has about 2.8 billion stock shares outstanding.