Chemical imaging with sufficient spatial resolution to resolve microparticles in tablets is essential to ensure high quality and efficacy in controlled release. The existing modalities have the following disadvantages: they are time-consuming or have poor spatial resolution or low chemical specificity. Here, we demonstrate an epi-detected mid-infrared photothermal (epi-MIP) microscope at a spatial resolution of 0.65 μm. Providing identical spectral profiles as conventional infrared spectroscopy, our epi-MIP microscope enabled mapping of both active pharmaceutical ingredients and excipients of a drug tablet.