Quality by design: discussing and assessing the solid dispersions risk.

The poor water solubility tops the list of undesirable physicochemical properties in the drug discovery and Solid Dispersions (SDs) has been frequently used to enhance dissolution of such compounds. Although, some challenges limit the studies of SD commercial application. During recent years, the Quality by Design (QbD) approach has begun to change drug development, and focus on pharmaceutical production, which shifted from an univariate empirical understanding for a systematic multivariate process. In this review, some possible variables during the development process, formulation and production of SDs were defined, introducing and applying the QbD concept. The proposed work presented important definitions as well as its application in the pharmaceutical product and process design, especially the challenges encountered during the development of formulations of poorly soluble drugs. In this aspect, the SD technique was deeply discussed, in which some important parameters during SD design and production were mentioned as method of production, polymers commonly used, methods for characterization and stability evaluation, in addition of biopharmaceutical considerations. Finally, a specific risk assessment for the design and production of SD and critical points were discussed, which was a positive evolution and may lead to better understanding of SD for a rational formulation.