**4. Film formation polymers**

The FFS is built on a foundation of polymers, and a range of polymers are available for this purpose. These polymers can be employed alone or in conjunction with other film-forming polymers to get the necessary film characteristics at skin temperature, these polymers should produce a clear flexible film. The **Table 1** shows a list of polymers, along with their molecular weights and properties [15].



**Table 1.** *Film formation polymers.*
