Relevance of production method on the physical stability and in vitro biopharmaceutical performances of olanzapine orodispersible film

This study assessed the relevance of the preparation process, namely solvent casting and hot-melt ram printing, on the biopharmaceutical performances of olanzapine orodispersible films (ODF) made of maltodextrin. Beside the clinical rationale, olanzapine was selected since it is subjected to polymorphism which impacts on its bioavailability. All ODF disintegrated in less than 3 min and showed content uniformity within the acceptable values. Dissolution testing in 3 mL of artificial saliva at pH=6.8 evidenced that cast and printed ODF released after 5 min about 2% and 100%, respectively; at higher volume, a yellow precipitate was formed after disintegration of the cast ODF. At pH=1.2, the t85% for cast ODF was reached after about 20 min and only the 90% olanzapine was dissolved increasing the pH to 6.8. These differences were explained by DSC, TGA and X-ray diffraction data which demonstrated that the casting method, which included the preparation of an aqueous slurry, favours the conversion from Form I to a hydrated one. Since extruded ODF resulted physically stable after 30 months, this suggests the potentiality of this technique to load in ODF drugs undergoing solid-state modification after exposure to aqueous media.