• Metabolism: Minimal metabolism via CYP enzymes Route of Elimination: When a oral dose of 2.5 - 40 mg bepotastine is given, 75%-90% of the dose was excreted unchanged in the urine by 24 hours. Half Life: Elimination half life = 2.5 hours
• Uses/Sources: For the symptomatic treatment of itchy eyes (caused by IgE-induced mast cell degranulation) due to allergic conjunctivitis. Used in the treatment of allergic rhinitis and uriticaria/puritus. [Wikipedia]
• Route of Exposure: Oral, Ophthalmic. Tmax, after single dose, opthalmic = 1.2 hours; Cmax, 1.5%, opthalmic dose = 7.3 ± 1.9 ng/mL; After 24 hours post-installation, levels of bepotastine are below quantifiable limit of 2 ng/mL. Minimal systemic absorption with opthalmic dosage form.

Because of a type 1 hypersensitivity reaction cascade that is triggered by antigen exposure, allergic conjunctivitis occurs. Allergen exposure is followed by conjunctival mast cell degranulation and histamine released as a result of the formation of complementary IgE cross-links on the conjunctiva. Due to the release of histamine, symptoms such as itching can be observed. Bepotastine works to relieve itchy eyes by three primary mechanisms of action. It is a non-sedating, selective antagonist of the histamine 1 (H1) receptor, a mast cell stabilizer, and it suppresses the migration of eosinophils into inflamed tissues to prevent tissue damage and worsening of allergic inflammation of the conjunctiva.