Particles, compositions, and methods that aid particle transport in mucus are provided. The compositions and methods may include, in some embodiments, modifying the surface coatings of particles including pharmaceutical agents that have a low water/aqueous solubility. In some embodiments, a surface coating includes a synthetic polymer having pendant hydroxyl groups on the backbone of the polymer, such as poly(vinyl alcohol) (PVA). Such compositions and methods can be used to achieve efficient transport of particles of pharmaceutical agents though mucus barriers in the body for a wide spectrum of applications, including drug delivery, imaging, and diagnostic applications. In certain embodiments, a pharmaceutical composition including such particles is well-suited for administration routes involving the particles passing through a mucosal barrier.