A prefilled glass syringe comprising an aqueous botulinum toxin formulation, the glass syringe comprising: (a) a syringe barrel made of glass including a proximal end and a distal end, and a generally cylindrical wall extending therebetween and defining a barrel lumen, the syringe barrel having a distally projecting tip with a fluid passage extending therethrough and communicating with the barrel lumen, wherein the generally cylindrical wall has an interior surface coated with a barrier layer, (b) a capping device having an outlet engaging portion sealingly engaging and closing the distal open outlet end of the syringe, (c) a plunger rod assembly which extends into the proximal end of the syringe barrel and includes a plunger stopper in sliding fluid-tight engagement with the cylindrical wall of the barrel lumen, wherein the plunger stopper has a coating on at least a portion of the plunger stopper that contacts the aqueous botulinum toxin formulation during storage and/or injection, characterized in that the barrier layer is a silicone layer, the outlet engaging portion is made of an elastomeric material selected from halogenated butyl rubber, styrene-butadiene rubber, and a mixture of isoprene rubber and halogenated butyl rubber, the plunger stopper is made of an elastomeric material selected from halogenated butyl rubber, styrene-butadiene rubber, and a mixture of isoprene rubber and halogenated butyl rubber, the coating on at least a portion of the plunger stopper is a fluoropolymer coating, the aqueous botulinum toxin formulation comprises water, botulinum toxin of serotype A, sodium chloride, sucrose, and human serum albumin, the aqueous botulinum toxin formulation has a pH value of between 6.1 and 7.3 during storage, and the activity of the botulinum toxin in the aqueous botulinum toxin formulation is not reduced by more than 25%, relative to the initial toxin activity, after storage of the prefilled syringe for 12 months at 5°C or 12 months at 25°C. (a) a syringe barrel made of glass including a proximal end and a distal end, and a generally cylindrical wall extending therebetween and defining a barrel lumen, the syringe barrel having a distally projecting tip with a fluid passage extending therethrough and communicating with the barrel lumen, wherein the generally cylindrical wall has an interior surface coated with a barrier layer, (b) a capping device having an outlet engaging portion sealingly engaging and closing the distal open outlet end of the syringe, (c) a plunger rod assembly which extends into the proximal end of the syringe barrel and includes a plunger stopper in sliding fluid-tight engagement with the cylindrical wall of the barrel lumen, wherein the plunger stopper has a coating on at least a portion of the plunger stopper that contacts the aqueous botulinum toxin formulation during storage and/or injection, the barrier layer is a silicone layer, the outlet engaging portion is made of an elastomeric material selected from halogenated butyl rubber, styrene-butadiene rubber, and a mixture of isoprene rubber and halogenated butyl rubber, the plunger stopper is made of an elastomeric material selected from halogenated butyl rubber, styrene-butadiene rubber, and a mixture of isoprene rubber and halogenated butyl rubber, the coating on at least a portion of the plunger stopper is a fluoropolymer coating, the aqueous botulinum toxin formulation comprises water, botulinum toxin of serotype A, sodium chloride, sucrose, and human serum albumin, the aqueous botulinum toxin formulation has a pH value of between 6.1 and 7.3 during storage, and the activity of the botulinum toxin in the aqueous botulinum toxin formulation is not reduced by more than 25%, relative to the initial toxin activity, after storage of the prefilled syringe for 12 months at 5°C or 12 months at 25°C.