Background/Objectives: Films in the mouth offer a promising alternative drug delivery system for oral administration, with several advantages over traditional oral formulations. Furthermore, their non-invasive nature and easy administration make them conducive to increasing patient compliance. The use of active agents in these films can further improve their drug delivery properties, making them an even more useful drug delivery system. Methods: In this research, carrageenan was used as a polymer, while glycerine was added as a plasticizer, furthermore, lidocaine hydrochloride and diclofenac sodium were used as the active agents. The prepared films were characterized by analytical techniques. Results: The results showed that glycerine reduced the mucoadhesivity and breaking hardness of the films and increasing the temperature made the films brittle. These results are also confirmed by the statistical analysis. Based on the FTIR results, glycerine can be used in films without structural changes. Conclusions: Based on the findings, films prepared from a solution with a concentration of 1.5% carrageenan and 1.5% glycerine at 70 °C are suitable as a drug delivery system for use on the buccal mucosa when combined with active agents. Carrageenan was successfully used as a carrier for two different types of active agents.