Does film coating always require a solvent or heat?

The assertion that film coating always requires a solvent or heat is accurate. Film coating processes typically involve the use of a polymer-based coating solution that necessitates a solvent for proper application. This solvent helps dissolve the coating material, allowing the coating to form a uniform layer on the tablet or particle surface once applied.

Additionally, heat may be used during some film coating processes to help evaporate the solvent quickly and ensure the coating solidifies properly on the substrate. While there are alternative methods or technologies being researched that could potentially minimize or even eliminate the need for solvents or heat, these are not standard practice in conventional film coating. As such, under the traditional definitions and practices relating to film coating, the statement holds true.