A new composition of analgesic bioadhesive healing microspheres in which each microsphere comprises at least:a.—a layer of a polyanion, where the polyanion may be an alginate.b.—a core coated with a polyanion consisting of a triblock copolymer non-ionic surfactant； poloxamer 188 or a mixture of them； and a volatile halogenated by-product anesthetic ether agent of methyl-isopropyl-ether in contact with the internal part of the polyanion layer, which may be sevoflurane.c.—a coating of a polycation in contact with the external part of the polyanion layer, which may be chitosan.
