Solid dispersions: revival with greater possibilities and applications in oral drug delivery

Improvement of oral bioavailability of poorly water-soluble drugs remains one of the most challenging aspects of drug development. Solid dispersions seem to be a viable technique for overcoming this problem. However, the practical applicability of these systems has remained limited because of difficulties in conventional methods of preparation, poor reproducibility of physicochemical properties, difficulties in dosage form development, and lack of feasibility for scale-up of manufacturing processes. This review addresses various aspects of solid dispersions and compiles some of the recent technology transfers from various fields such as the chemical, food, and polymer industries for the preparation of solid dispersions that can lead to highly efficient and controlled large-scale manufacturing. Some of the practical aspects to be considered for the preparation of solid dispersions, such as selection of carrier and methods of physicochemical characterization, along with an insight into the release mechanism of drugs are also discussed. Finally, an in-depth rationale for limited commercialization of solid dispersions and recent revival has been considered.