Diluted chemotherapy drugs that were given to more than 1,200 cancer patients were discovered after an Ontario pharmacy assistant noticed the new IV bags of medication needed to be refrigerated.

Peterborough Health Sciences Centre pharmacy assistants Craig Woudsma and Judy Turner gave testimony about how they came to discover the diluted cancer drugs before an Ontario legislative committee Tuesday afternoon. The committee is looking into the regulation of non-accredited pharmaceutical companies.

Woudsma said that he first noticed issues with the bags of drugs supplied by Marchese Hospital Solutions in March.

When he compared the labels on the Marchese drugs against the labels on the drugs supplied by Baxter – the previous supplier -- he noticed discrepancies.

A colleague noticed the new drugs needed to be refrigerated, he said. And he noticed that the Marchese-supplied bags didn’t state the total volume or final concentration of the drug.

Woudsma said that when the issue was raised with Marchese, the company told them that each bag contained the correct amount of medication.

“We reiterated that overfill was an issue and the concentration is an issue and the response was quite clearly that the concentration didn’t matter,” he said.

It was later discovered through testing that the bags contained too much saline, which watered down the drugs cyclophosphamide and gemcitabine by up to 20 per cent.

The pharmacy assistants have also said that they noticed that the Marchese bags appeared fuller than others.

They soon realized that the overfilled bags had been sent to four hospitals in Ontario and one in New Brunswick for more than a year.

More than 1,200 cancer patients have since been alerted that they received diluted medications. More than 150 of those patients have since died, though it’s not known if the diluted medications played any role in their deaths.

Officials from the Ontario government and Health Canada have recognized that there was a lack of oversight over Marchese Hospital Solutions. They also acknowledged that they don’t know exactly how many companies like Marchese are in operation.

Woudsma said he hopes his testimony will lead to tighter oversight.

The committee previously heard testimony that Marchese did not account for the extra saline in the bags and that the bags were not properly labelled with the exact concentrations of the medications.

A representative from Medbuy, a group purchasing organization that arranged the contract between Marchese and four Ontario hospitals, said that workers at Marchese should have attached labels that accurately described the bags’ contents.

Medbuy president and CEO Kent Nicholson said the contract it provided to Marchese wasn't difficult to understand.

"In our mind, the specification was clear, the response was clear," he said in testimony at the committee Monday.

"We were reliant on the manufacturer understanding the specification, producing the product to that specification, labelling their product to that specification."

Nicholson also said the affected hospitals didn't "misadminister" the drugs, as Marchese has suggested.

With files from CTV Toronto's Zuraidah Alman and The Canadian Press