Interrelation between Disintegration, Dissolution and Permeation of Orodispersible Films (ODFs) Containing Ketoprofen

Sodium hydroxide solution as solvent transferred ketoprofen from the poorly soluble acidic form to the freely soluble sodium salt. Faster disintegration (500 µm: 9.67 s) and dissolution (release after 180 s: 500 µm: 47.45%) were detected compared to films made from organic solvents or suspensions, which fits well to the good solubility of ketoprofen sodium. As expected, the slowest permeation (4.28*10-6cm/s) was detected for ketoprofen films based on sodium hydroxide. In films based on organic solvents or a suspension a much slower disintegration (500 µm 2-propanol: 87 s; suspension: 34 s) and dissolution (500 µm 2-propanol: 5.9%; suspension: 6.5%) was observed, as ketoprofen was present in its acidic form. Despite the reduced amount of dissolved ketoprofen, a higher permeation (500 µm 2-propanol: 1.1*10-5cm/s; suspension: 8.1*10-6cm/s) was observed. This is due to the higher lipophilicity of the acidic form. Compared to the organic solvent films, a faster dissolution and disintegration occurred for the suspension films. The higher amount of dissolved ketoprofen did not result, in a faster permeation. The opposite turned out to be the case for the 500 µm films. No difference regarding the permeation was detected for the 300 µm films. Conclusion A fast disintegration or fast dissolution of ODFs does not necessarily lead to a fast permeation. The opposite trend was observed in this work.