Suppressing Bitterness in Orally Disintegrating Films by Coating Drug Particles With a pH-Dependent Polymer

Orally disintegrating films (ODFs) disintegrate and dissolve in the mouth, which creates challenges such as bitter taste and particle roughness. One of the most useful methods for suppressing bitterness in solid dosage forms is coating drug particles with a polymer to physically prevent contact between the drug and the taste buds. Because ODFs are extremely thin, the volume available for particle incorporation is limited; therefore, it is necessary to prepare fine coated drug particles with a size smaller than 200 µm, which also helps mitigate particle roughness in the oral cavity. In this study, we designed and prepared ODFs incorporating taste-masked drug particles for easy administration and improved adherence to drug therapy.

We used quinine hydrochloride (QH) as a model bitter active pharmaceutical ingredient (API), polyvinylacetal diethylaminoacetate (AEA), a pH-dependent polymer, as a coating agent, and hydroxypropyl methylcellulose (HPMC) as the film-forming agent. The ODFs containing taste-masked QH granules and the corresponding granules themselves were evaluated using a taste-sensing system. The disintegration, drug dissolution profiles, and physical properties of the ODFs were also evaluated.

We prepared QH granules with the targeted median diameter (d₅₀) and geometric standard deviation (σ_g), and the initial release of QH from these granules was less than 5% within 2 min. We also demonstrated, using the same system, that ODFs containing these granules delayed and suppressed the emergence of QH-induced bitterness. The disintegration time of the ODFs was less than 30 s, and their tensile strength remained above the 2 MPa threshold required for handling.

We successfully prepared ODFs that suppressed the bitterness of QH while maintaining a short disintegration time and practical mechanical strength.