Review of Crystallization in Nanoconfinement Created by Emulsions and Microemulsions for Pharmaceutical Applications

In the creation of solid dosage forms in the pharmaceutical industry, crystallization has a large impact on the properties of the payloads and matrix, such as melting point, polymorphic form, and crystallinity. Control of the crystallization of the drugs and the material in the matrix using a process of crystallization under confinement to achieve desirable properties is challenging. Emulsions allow the encapsulation of drugs for use in pharmaceutical applications. The limited volume available for crystallization under confinement in emulsions has a significant effect on the crystallization of the payloads and matrices. We discuss here advances in improving the characteristics of pharmaceutical products through the use of crystallization under confinement created by an emulsion. We also review the methods for preparing emulsions, in which the droplets act as a template for the crystallization under confinement. In addition, the influences of crystallization in emulsions on solubility, release profile of payloads, permeability, and polymorphism are reviewed.