The dermal anesthetic market is dominated by one single preparation, called EMLA(R) (Astra) and consisting of a mixture of lidocaine base (2.5%) and prilocaine base (2.5%). The major problem with EMLA is a very long onset time for dermal anesthesia, up to two hours. The annual worldwide sale of EMLA is only in the range of US $60M, which reflects the drawback with the long onset time. After preliminary studies, we have determined that ester-type local anesthetics (ex. tetracaine, oxybutynin) cause too much tissue irritation to be useful as dermal anesthetics and amide-type local anesthetics (ex. lidocaine, bupivacaine) do not have the penetration properties needed for dermal anesthesia. We have identified and synthesized members of a new, structurally different series of non-ester, non-amide local anesthetic compounds. Results from ongoing studies indicate that the new compounds offer dermal anesthesia of short onset and long duration. During Phase I of the proposed project we intend to synthesize additional compounds and perform pharmacological testing and select a drug candidate compound according to the criteria outlined in this proposal. After the conclusion of the Phase I studies, we intend to apply for Phase II funding to perform the additional testing and preclinical development needed to bring a selected drug candidate compound to the IND stage.
New and effective dermal anesthetics without the long onset time of EMLA will have the potential to dominate and significantly expand the present market for dermal anesthetics. Drugs emerging from this work will have excellent potential for commercial development.
