ABSTRACT:
There are many ways to coat tablets. Coatings are a very important part in the formulation of pharmaceutical dosage form to achieve excellent formulation quality. Coating is also providing superior physical and chemical protection for the drugs in the dosage forms, and modification of drug release characteristics. Almost all types of film coatings are applied as aqueous- or organic-based polymer solutions. Both film coating techniques have some disadvantages. Solventless coating technologies can overcome many of the disadvantages associated with the use of solvents (e.g., solvent exposure, solvent disposal, and residual solvent in product) in pharmaceutical coating. Solventless processing reduces the overall cost by eliminating the tedious and expensive processes of solvent disposal/treatment. In addition, it can significantly reduce the processing time because there is no drying/evaporation step. This environment-friendly performance without any heat in most cases (except hot-melt coating) and thus can provide an alternative technology to coat temperature-sensitive drugs. In this review discusses about 6 different types of solventless coating methods. Solventless coating techniques are compression coating, hot-melt coating, supercritical fluid spray coating, electrostatic coating, dry powder coating, and photocurable coating. All these techniques that can be used to coat the pharmaceutical dosage forms with excellent quality within less consuming time.