Differin is a potent photosensitizer (=increases your skin sensitivity to the sun). Thus, it should not be applied in the morning. If you like to use both products, you can use them on alternate nights: one night, the MDacne night cream, and the other night, the differin.
Best Retinol 0.5% + Niacinamide 4% (Amazon).
Best Retinol 0.25% + Niacinamide 2% (Amazon).
To find the right acne treatments for your unique skin, take the free skin assessment by clicking here.