There are topical formulations that have been designed specifically to treat oral mucosal diseases. Local drug delivery may provide a more targeted and efficient option than systemic delivery (such as pills) for diseases of the oral mucosa. Oral mucosal delivery has the potential to treat many different conditions and diseases, such as oral cancer, mucositis, lichen planus, herpes simplex, candidiasis, recurrent aphthous stomatitis, vesiculo-bullous diseases, neuropathic pain and salivary dysfunction. (Sheikh et al, 2013)

Why to deliver a medication through the oral mucosa?

  1. To avoid the stomach and first-pass elimination
  2. To avoid the influence of the presence of food
  3. Direct access to a lesion or condition
  4. Quick absorption

Intraoral Permeability

The oral mucosa is not a uniformly, highly permeable tissue like the gut, but shows regional variation. The keratinized areas (thicker), such as gingiva and hard palate, are least permeable and nonkeratinized lining areas (such as the tissue under the tongue) are most permeable. (Squier 1991)

Holding medication in place!

One of the major limitations associated with buccal delivery is low permeation of therapeutic agents across the mucosa. Various substances have been explored as permeation enhancers to increase the flux/absorption of drugs through the mucosa, but irritation, membrane damage, and toxicity are always associated with them and limit their use. (Sohi et al, 2010)

Technological advances in mucoadhesive, sustained drug release, permeability enhancers and drug delivery vectors are increasing the efficient delivery of drugs to treat oral and systemic diseases.  (Hearnden  et al, 2011)

It is possible to use a tissue coverage with an appliance similar to a bleaching tray. These oral appliances, whether used alone as a physical barrier or as a vehicle to deliver topical anesthetic, represent a safe and effective modality for the management of neuropathic orofacial pain disorders. (Bavarian  et al, 2022)

References

Sheikh S, Gupta D, Pallagatti S, Singla I, Gupta R, Goel V. Role of topical drugs in treatment of oral mucosal diseases. A literature review. N Y State Dent J. 2013 Nov;79(6):58-64. PMID: 24600767.

Squier CA. The permeability of oral mucosa. Crit Rev Oral Biol Med. 1991;2(1):13-32. doi: 10.1177/10454411910020010301. PMID: 1912142.

Kurosaki Y, Kimura T. Regional variation in oral mucosal drug permeability. Critical reviews in therapeutic drug carrier systems. 2000;17(5):467-508.

Sohi H, Ahuja A, Ahmad FJ, Khar RK. Critical evaluation of permeation enhancers for oral mucosal drug delivery. Drug Dev Ind Pharm. 2010 Mar;36(3):254-82. doi: 10.1080/03639040903117348. PMID: 19663558.

Hearnden V, Sankar V, Hull K, Juras DV, Greenberg M, Kerr AR, Lockhart PB, Patton LL, Porter S, Thornhill MH. New developments and opportunities in oral mucosal drug delivery for local and systemic disease. Adv Drug Deliv Rev. 2012 Jan;64(1):16-28. doi: 10.1016/j.addr.2011.02.008. Epub 2011 Mar 1. PMID: 21371513.

Bavarian R, Khawaja SN, Treister NS. Oral appliances in the management of neuropathic orofacial pain: A retrospective case series. Oral Dis. 2022 Apr;28(3):805-812. doi: 10.1111/odi.13824. Epub 2021 Mar 9. PMID: 33650141.