The couple recently put up their home up for sale, and a real estate agent, who was preparing the house for an open-house viewing, discovered their bodies.
The two were found dead after police responded to a medical call just before noon (1700 GMT) at their home in an affluent section of northeast Toronto.
"Barry, Honey, rest in peace".
Sherman, 75, founded privately held Apotex in 1974, growing it by introducing large numbers of low-priced generic drugs that took market share from branded pharmaceuticals.
Taylor said that a "death investigation" is taking place and that the coroner is investigating.
According to Constable David Hopkinson, "The circumstances of their death appear suspicious and we are treating it that way". He is estimated to be worth almost $5 billion and is believed to be the 15th richest person in Canada.
Ontario Health Minister Eric Hoskins sent a tweet expressing shock at the death of his "dear friends", who he described as "wonderful human beings".
Privately held Apotex says it is the largest Canadian-owned pharmaceutical firm, with annual sales of more than C$2 billion. It has operations in more than 45 countries, including the United States.
The couple was known for their philanthropy, giving tens of millions of dollars to hospitals, universities and Jewish organizations, CBC reported.
Toronto police called the deaths suspicious.
Sherman has also been an active philanthropist and had also become an active fundraiser for Prime Minister Justin Trudeau's Liberal party in recent years.
"All of us at Apotex are deeply shocked and saddened by this news and our thoughts and prayers are with the family at this time,"Apotex wrote in a news release".
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