RECENT TECHNIQUES OF PHARMACEUTICAL SOLVENTLESS COATING: A REVIEW

The coating of solid pharmaceutical dosage forms began in the 9th century B. C., with the Egyptians. Conventional coating techniques are based on solvents or water. Solventless coatings are alternative technique of coating. In solventless coating, the coating material is directly spread on the core and then it is cured by special method to form coat. Solventless coating avoids the use of water or it reduces to very small amounts with respect to the coating material hence it overcomes the limitations of conventional coating such as need for time, energy consuming, drying steps and the most important drug stability issues. A variety of solventless coating approaches are described in this review as powder coating, hot melt coating, supercritical fluid coating, magnetically assisted impaction coating, Plasma enhanced chemical vapor deposition. This review summarizes basic principle and process of the coating techniques.