The present invention relates to an injection device suitable for intraepidermal and/or intradermally and/or subcutaneously comprising a sterile and injectable composition, said composition being prepared by a method comprising at least the steps of:a) providing at least one gel of a hyaluronic acid or a salt thereof, said hyaluronic acid being selected from a crosslinked hyaluronic acid form, a non-crosslinked hyaluronic acid form or a mixture thereof；b) adding to said gel of hyaluronic acid at least mepivacaine hydrochloride as anesthetic agent； andc) sterilizing the mixture obtained in step b).
