Adhesion between pharmaceutical particles, including excipients and active pharmaceutical ingredients, and solid surfaces is a key factor in the processing of solid dosage forms. The surface forces causing adhesion of particles to substrates are studied here at the micro- and nano-scale. Specifically, the study has developed a detailed understanding of particle adhesion, and has quantified experimentally and theoretically the relative importance of the geometry, surface roughness and medium properties on the adhesion of approaching bodies as their sizes are scaled over these length scales. In addition, a simulator developed in this study predicts the adhesion of particles to chemically heterogeneous surfaces (e.g. substrates having nanoscale features of different materials imprinted on the surface), including the effects of the discontinuity in the interfacial composition. This facilitates prediction of the dynamics of particle motion as particles approach nanopatterned surfaces. Finally, the modeling and simulation protocols developed describe the adhesion behavior of particles towards ultra-thin films as a function of coated film thickness and composition.