Note that he is probably not permitted to import prescription medications, even for personal use without a licence. As he is here applying for PR under the "Spouse or Common-Law Partner in Canada Class" it's unlikely that he would be considered a "visitor" for Customs purposes.
https://www.cbsa-asfc.gc.ca/publications/dm-md/d19/d19-9-1-eng.html
Personal Importation of Prescription Drugs
Health Canada considers a personal importation as an importation by an individual for their own use or for the use of a person under their care or guardianship and which does not meet the definition of a commercial importation as set out in paragraph 16 of this memorandum.
22. Under C.01.045 of the
Food and Drug Regulations, importation of prescription drugs is restricted to practitioners, drug manufacturers, wholesale druggists or registered pharmacists, or a resident of a foreign country while a visitor in Canada. Note that drugs imported by practitioners for treating patients are not considered to be personal importations but rather commercial importation for sale.
Canadian Residents
23. Health Canada may exercise enforcement discretion to permit a Canadian returning from abroad to bring with them, on their person, a single course of treatment or a 90-day supply based on the directions for use, whichever is less, of a prescription drug. This discretion is generally reserved for Canadian residents returning to Canada with prescription drugs which were dispensed for a treatment prior to leaving Canada, or drugs obtained through a filled prescription to treat an illness while abroad.
24. Prescription drugs imported in this fashion must be for the individual's personal use or the use of a person for whom they are responsible and with whom they are travelling.Additionally, all personal importations of prescription drugs must be packaged in the hospital, pharmacy dispensing or retail packaging, or have the original label affixed to it clearly indicating what the product is and what it contains.
25. The CBSA may detain and refer prescription drugs to Health Canada when these conditions are not met.
26. Canadian residents may not import prescription drugs by mail or courier.
Non-Residents of Canada
27. Visitors to Canada and non-residents arriving from abroad are permitted to import a single course of treatment or a 90-day supply of a prescription drug hand-carried for their personal use or the use of a person under their care and with whom they are travelling.
28. Visitors and non-residents are allowed to import a single course of treatment or a 90 day supply of a prescription drug by mail or courier.
29. All personal importations of prescription drugs must be packaged in the hospital, pharmacy dispensing or retail packaging, or have the original label affixed to it clearly indicating what the product is and what it contains.
30. The CBSA may detain and refer prescription drugs to Health Canada when these conditions are not met.