@BazM, From what I can tell the Aficio SP C200n toner will suite the Ricoh MP C4501, the letters and numbers are just different models’, but the chips might be a different matter, so might the cart dimensions.
Your best bet to is to request an answer from the dealer when you first purchase the 4 carts. specifying whether the SP C200 carts will fit into the MP C4500 machine...