The aim of this paper is theophylline (THP) inclusion into xanthan–chitosan polyionic complex (Xa–CS) and the study of its in vitro and in vivo kinetic release. Xa–CS hydrogel was obtained by ionic complexation between two oppositely charged polysaccharides. THP was loaded into the Xa–CS matrix by diffusion of the drug solution. The obtained samples were characterized by FTIR spectroscopy, SEM microscopy and study of the swelling behavior. THP in vitro release experiments were carried out in conditions mimicking the gastrointestinal environment. The chosen drug dose for in vivo study was
15 mg THP/Kg body weight of THP powder or an equivalent dose in complex form. THP serum concentrations were determined by an HPLC assay. The THP peak serum concentration (Cmax) was 7.18 lg/ml for free THP and
AUC0–48 was 25.76 lg h/ml, while in the case of Xa–CS–THP, Cmax was of 5.72 lg/ml and AUC0–48 = 45.72 lg h/ml.
The in vivo study regarding the behaviour of the obtained formulation, showed an increase bioavailability