Best LA agent for intranasal instillation:
It is formulated in a pre-filled, single-use nasal sprayer: 6 mg tetracaine HCl and 0.1 mg oxymetazoline HCl (equivalent to 5.27 mg tetracaine and 0.088 mg oxymetazoline) in each 0.2 mL spray. It is intended for intranasal use only, and administration should be on the same side as the maxillary tooth being treated. It is recommended to wait 10 minutes after administration and then determine anesthesia effectiveness.
Topical tetracaine has been safely and effectively used intranasally by the ear-nose-throat (ENT) medical community for ENT procedures. Patients noticed that their upper teeth felt numb, which led to interest in the application of this type of anesthesia for dentistry. The oxymetazoline (the active ingredient in Afrin and other nasal decongestant sprays) was added to Kovanaze to slow systemic absorption of the tetracaine and improve the duration of action.
https://www.rdhmag.com/patient-care/article/16409318/needleless-intranasal-spray-kovanaze-product-for-local-anesthesia-makes-its-debut
Articaine
Tetracaine
Lignocaine
Bupivacaine