Topical semi-solid dosage forms are normally presented in the form of creams, gels, ointments or pastes. In addition to API, they may also contain emulsifiers, viscosity-increasing agents, antioxidants or stabilizing agents, depending on the desired therapeutic effect and the site of action or administration.

Topical formulations present many challenges related to bioavailability and stability. Control of critical material attributes such as particle size and viscosity are important to ensure formulation’s target profile is achieved. Malvern has an array of technologies to help characterize these attributes. For example, Malvern’s Morphologi G3-ID can help bioequivalence characterization through unambiguous particle size distribution measurement of the API in complex topical formulation matrices.