MONTREAL -- Valeant Pharmaceuticals plans to deliver up to US$600 million in annual savings to the U.S. health-care system starting next year after agreeing to cut the prices of several of its drugs as part of distribution agreements with the Walgreens retail chain.

The Quebec-based company said it will drop wholesale prices for branded prescription-based skin and eye-care products by 10 per cent.

The price reductions under the 20-year agreement with one of the largest U.S. drug chains will be introduced in six to nine months.

Walgreens will also distribute more than 30 of Valeant's branded products at comparable generic prices, starting in the second half of 2016. The average price decrease is expected to be more than 50 per cent, with reduced prices ranging between five and 95 per cent.

The price cuts don't apply in Canada where Valeant doesn't have similar distribution agreements with pharmacy retailers such as Shopper's Drug Mart, Jean Coutu or the Rexall Group.

Valeant's pricing practices have been under investigation by U.S. authorities, including at the U.S. Congress, since the company dramatically increased prices for some specialty products this year.

The company has also come under fire as the result of a civil suit by a small U.S. pharmacy that shed new light on Valeant's distribution agreements and practices.

"We have listened to what the marketplace is saying and we've taken positive steps to respond," Valeant chairman and CEO Michael Pearson said in a news release on Tuesday, a day before he is scheduled to hold a conference call with industry analysts.

The new distribution agreement with Walgreen -- a chain of more than 8,000 retail outlets -- follows Valeant's decision to sever ties with mail-order pharmacy Philidor Rx Services. That relationship came to light as a result of a court battle between Valeant and another mail-order pharmacy.

Valeant says the Walgreens agreement will be used as a model for distribution deals with independent retail pharmacies.

"Our goal is to create a system that allows prescription medications to be dispensed and insurance claims adjudicated in an efficient manner while allowing physicians to focus their efforts on what matters most: patient care," Pearson added.

Patients with commercial insurance can benefit from lower out of pocket costs, while the program will also be available for patients without insurance coverage. However, reduced costs won't apply for those on government insurance.

Walgreens president Alex Gourlay said the new direct distribution model will increase efficiency and improve service for patients.