Particle size is an important parameter in any pharmaceutical product. This is primarily because the particle size and distribution are directly related to the dissolution rate of the active pharmaceutical ingredient (API). The particle size of the API and excipients present in suspension-based products may also affect physical characteristics such as the product's viscosity, and therefore mouth feel, and its stability over time.
This application note describes the characterization of two indigestion treatments, both of which are suspension-based formulations. One product claims to be fast acting, the other long lasting whilst both have the same composition (Table 1). The study aims to link the particle size of the ingredients to the product's solubility (and hence bioavailability) and the rheology of suspensions.