Coatings are a vital part in the formulation of pharmaceutical dosage form to attain grander aesthetic quality, physical and chemical protection for the drugs in the dosage forms, and modification of drug release characteristics. Most film coatings are pragmatic as aqueous-or organic-based polymer solutions. Both organic and aqueous film coating bring their own shortcomings. Solvent less coating technologies can flabbergasted several of the hindrances associated with the use of solvents in pharmaceutical coating. Dry coating is a coating technology for solid pharmaceutical dosage forms plagiaristic from powder coating of metals. In this technology, powdered coating materials are directly coated onto solid dosage forms without using any solvent and then heated and cured to form a coat. As a result, this technology can flabbergasted such drawbacks caused by solvents in conventional liquid coating as serious air pollution, high time and energy consumption and expensive operation cost encountered by liquid coating. Solventless coating eludes the use of water or it lessens to very trivial amounts with respect to the coating material hence it incapacitates the precincts of orthodox coating such as need for time, energy consuming, drying steps and the most important drug stability issues. In addition, it can ominously shrink the processing time because there is no drying step. These environment-friendly processes are performed without any heat in most cases and thus can deliver an unconventional technology to coat temperature-sensitive drugs. This review converses and associates different solventless coating methods compression coating, hot-melt coating, supercritical fluid spray coating, electrostatic coating, dry powder coating, and photo curable coating that can be used to coat the pharmaceutical dosage forms.
Keywords: Solventless coating technology, Plasticizer-dry-coating, Photocurable coating