The invention relates to a new composite based on hydroxypropyl-ß-cyclodextrin, sucralose, a pharmaceutically active ingredient (API) complexed in said hydroxypropyl-ß-cyclodextrin, and optionally an aqueous vehicle. The composite is obtainable by a complexation process of the API in hydroxypropyl-ß-cyclodextrin, carried out in the presence of sucralose. The composite ensures a surprisingly high API bioavailability through buccal route of absorption, due to a high absorption rate through the oral membrane. The composite is therefore suitable for the preparation of oromucosal pharmaceutical compositions, e.g. buccal or sublingual tablets, orodispersible film, etc., having high bioavailability.