Canon has patented the design on some of their toner cartridges. As a result, compatible cartridges may be unavailable. In this case, remanufactured toner cartridges and toner refill kits provide an economic alternative to new OEM Canon toner cartridges.
Canon offers a wide range of cartridges for their printers. The link above provides a list of top suppliers for Canon toner cartridges and other printer supplies. Check with the suppliers to see if they have your toner cartridge available.