Enhanced In Situ Availability of Aphanizomenon Flos-Aquae Constituents Entrapped in Buccal Films for the Treatment of Oxidative Stress-Related Oral Diseases: Biomechanical Characterization and In Vitro/Ex Vivo Evaluation

In recent years, the key role of oxidative stress in pathogenesis of oral diseases has beenemphasized and the use of antioxidant agents has been encouraged. Aphanizomenon flos-aquae (AFA) isa unicellular blue-green alga with antioxidant and anti-inflammatory properties. The aim of this studywas the formulation and characterization of mucoadhesive thin layer films loaded with AFA, finalizedto the treatment of oxidative stress (OS)-related oral diseases. First, to enhance the bioavailabilityof AFA constituents, the raw food grade material was appropriately treated by a high frequencyhomogenization able to disrupt cell walls. Thus, Eudragit® E100-based buccal films were producedby the solvent casting method, containing 7% and 18% of AFA. The films, characterized by uniformityin thickness, weight, and drug content, showed low swelling degree, good muco-adhesiveness andcontrolled drug release. The mechanical tests showed elastic moduli of films of almost 5 MPa that iswell-suitable for human buccal applications without discomfort, besides biaxial tests highlighted amarked material isotropy. Permeation studies through porcine mucosae demonstrated the ability offilms to promote AFA penetration in the tissues, and when sublingually administered, they produceda drug flux up to six-fold higher than an AFA solution. The new formulations represent an interestingalternative for the development of cosmetics and nutraceuticals with a functional appeal containingplant extracts.