Review Charts a New Generation of Local Drug Delivery for Oral Cancer

A new review led by Professor Nurhasni Hasan of the Faculty of Pharmacy at Hasanuddin University in Indonesia, with researchers from Indonesia, Japan and China, examines local drug-delivery systems for oral squamous cell carcinoma (OSCC), one of the most common cancers of the mouth, head and neck. Published in the European Journal of Pharmaceutics and Biopharmaceutics on August 1, 2026, it surveys mucoadhesive films and patches, oral sprays, in situ gels and injectable hydrogels, formats that deliver medicine straight to the tumor, raising drug exposure there while limiting exposure elsewhere.

But the mouth works against this constantly: saliva dilutes and washes medicine away, while chewing, speaking, tongue movement and enzymes can degrade or dislodge delivery systems, what the review calls "hard constraints" any local treatment must overcome. No single format is a universal fix, the researchers argue; the best choice depends on the drug and the tumor.

Flat, accessible lesions suit mucoadhesive films that stay attached to the mucosa; irregular or infiltrative lesions may need gels or injectable hydrogels that conform to complex tissue and reach deeper layers; sprays are convenient but clear quickly with saliva. "There is a tendency to think of drug delivery as a problem that can be solved by developing a better formulation," Hasan said. Radiotherapy and chemotherapy often cause dry mouth and mucosal damage that can affect drug release and adhesion, so formulations tested in simplified laboratory conditions may not behave the same way in patients.

None of these systems is yet an established OSCC treatment. Mucoadhesive films and patches show stronger near-term potential because similar buccal formats already have regulatory and manufacturing precedents, while injectable hydrogels remain promising for irregular lesions but face added challenges in manufacturing and long-term biocompatibility. "The goal should be to make local treatment more predictable," Hasan said. "We need delivery systems that researchers can evaluate consistently and clinicians can realistically use."