Recent insights, challenges and emerging trends in sublingual drug delivery system

An oral solid dosage form (OSDF) refers to pharmaceutical formulations that are orally administered in a solid form, including tablets, capsules, or powders. These dosage forms are intended to be swallowed and dissolved in the gastrointestinal tract, facilitating the systemic delivery of the active pharmaceutical ingredient to the body. The oral or buccal cavity is a desirable rout for drug delivery due to its simplicity and ease of administration. This route enables the administration of medications with both systemic and local effects through mucosal and transmucosal delivery. In the transmucosal route, drug absorption via the mucosal barrier reaches the systemic circulation, whereas in the mucosa scenario, it aims to achieve a site-specific release of the medication on the mucosa. The sublingual area of the buccal cavity is the most favourable site for drug absorption. Greater bioavailability and improved patient compliance result from the drug's fraction that is absorbed by the sublingual blood vessels avoiding the hepatic first-pass metabolism. Various dosage forms are examined in detail, such as sublingual tablets including fast dissolving and bio adhesive formulations—films, sprays, wafers, and emerging vaccine delivery systems. The sublingual dosage form is primarily utilized in managing conditions such as migraines, cardiovascular diseases (e.g., angina), schizophrenia, anxiety, allergies, and for the management of pain. The article illustrates marketed products and current clinical applications, offers insights into future prospects for sublingual delivery, and serves as a valuable resource for pharmaceutical scientists and clinicians seeking to understand and improve sublingual drug delivery technologies.