Botulinum toxin prefilled syringe system

1. A botulinum toxin prefilled syringe system comprising:

a syringe barrel of glass, the syringe barrel including an inner surface defining a chamber containing a liquid botulinum toxin formulation, having a proximal end and a distal end, and having a label attached to an outside surface of the syringe barrel;

a plunger stopper slidably positioned inside the syringe barrel and providing a fluid-tight seal of the proximal end of the syringe barrel;

a closure device attached to the distal end of the syringe barrel, the closure device having an outlet engaging portion sealingly engaging and closing a distal open outlet end of the syringe system to prevent leakage of the liquid botulinum toxin formulation;

wherein the plunger stopper has a plurality of annular ribs providing multiple discrete contact areas to engage with the inner surface of the syringe barrel, wherein the plurality of annular ribs of the plunger stopper is three to five annular ribs, and

wherein the botulinum toxin prefilled syringe system has a normalized maximum gliding force of 15 N or less, as measured at a temperature of 20° C. and using a 32 G×½″ needle and a displacement speed of 100 mm/min, wherein the normalized maximum gliding force is defined as follows:

GF max =GF measured ×( d barrel ) 2 /( D barrel ) 2

wherein:

GF max is the normalized maximal gliding force in N,

GF measured is the measured highest gliding force in N before the plunger stopper finishes its course at the distal end of the syringe barrel,

d barrel is the barrel inner diameter of a reference syringe and is 6.35 mm, and

D barrel is the inner barrel diameter in mm of the prefilled syringe system, and

the botulinum toxin prefilled syringe system has a normalized break loose force of 8 N or less, as measured at a temperature of 20° C. using a 32 G×½″ needle and a displacement speed of 100 mm/min, wherein the normalized break loose force is defined as follows:

BLF norm =BLF measured ×( d barrel ) 2 /( D barrel ) 2

wherein:

BLF norm is the normalized break loose force in N,

BLF measured is the measured break loose force in N and is defined as the highest force between 0 and 2 mm plunger displacement distance,

d barrel is the barrel inner diameter of a reference syringe and is 6.35 mm, and

D barrel is the inner barrel diameter in mm of the prefilled syringe system, wherein the multiple discrete contact areas each provide an independent seal with the inner surface of the syringe barrel,

wherein the annular ribs extend outward radially from an axis of the plunger stopper,

wherein the annular rib located adjacent to the distal end of the plunger stopper has a greater Full Width at Half Maximum (FWHM) than the other annular ribs of the plunger stopper, wherein the FWHM is the width in an axial direction of the plunger stopper between two points on the surface of an annular rib, wherein the two points are located at half the maximum height of the annular rib in a perpendicular direction to the axis of the plunger stopper, and

wherein the distance between any two proximal adjacent annular ribs, except the most distal annular rib, in the axial direction of the plunger stopper is more than two times the sum of the full width at half maximum (FWHM) of the two proximal adjacent annular ribs.

2. The botulinum toxin prefilled syringe system of claim 1 , wherein a normalized break loose force is 6 N or less, as measured at a temperature of 20° C. using a 32 G×½″ needle and a displacement speed of 100 mm/min.

3. The botulinum toxin prefilled syringe system of claim 1 , wherein a normalized dynamic gliding force is 15 N or less, as measured at a temperature of 20° C. using a 32 G×½″ needle and a displacement speed of 100 mm/min, wherein the normalized dynamic gliding force is defined as follows:

DGF norm =DGF measured ×( d barrel ) 2 /( D barrel ) 2

wherein:

DGF norm is the normalized dynamic gliding force in N,

DGF measured is the mean gliding force calculated from the measured gliding forces at ⅓ and ⅔ of the total plunger displacement distance in N,

d barrel is the barrel inner diameter of a reference syringe and is 6.35 mm, and

D barrel is the inner barrel diameter in mm of the prefilled syringe system.

4. The botulinum toxin prefilled syringe system of claim 3 , wherein the normalized dynamic gliding force is 15 N or less after storage of the botulinum toxin prefilled syringe system for 12 to 24 months at 2 to 8° C. or for 12 to 24 months at 25° C., as measured at a temperature of 20° C. using a 32 G×½″ needle and a displacement speed of 100 mm/min.

5. The botulinum toxin prefilled syringe system of claim 1 , wherein

(i) the plunger stopper has a normalized total contact area with the inner surface of the syringe barrel of 70 mm 2 or less, wherein the normalized total contact area is calculated as follows:

TCA norm =TCA calc ×( d barrel ) 2 /( D barrel ) 2

wherein:

TCA norm is the normalized total contact area in mm 2 ,

TCA calc is the calculated total contact area in mm 2 and is defined as the sum of the contact surfaces (CT rib ) of each annular rib in mm 2 , wherein CT rib =2πrh, with r being the greatest distance perpendicular to the axis of the plunger stopper between a point on the surface of the annular rib and the axis of the plunger stopper in mm, and h being the full width at half maximum (FWHM) of the annular rib in mm, the FWHM being defined as the width in the axial direction of the plunger stopper between those two points on the surface of the annular rib which are half the maximum height of the annular rib in perpendicular direction to the axis of the plunger stopper,

d barrel is the barrel inner diameter of a reference syringe and is 6.35 mm, and

D barrel is the inner barrel diameter in mm of the prefilled syringe system, and/or

(ii) the percentage of the calculated total contact area of the plunger stopper with the inner surface of the syringe barrel relative to the total side face area of the plunger stopper is 50% or less, wherein the calculated total contact area (TCA calc ) is defined as in (i) and the total side face area of the plunger stopper is defined as follows:

TSFA=2π r max H

wherein:

TSFA is the total side face area of the plunger stopper in mm 2 ,

r max is the greatest distance perpendicular to the axis of the plunger stopper between a point on the surface of any annular rib and the axis of the plunger stopper in mm, and

H is the total length of the plunger stopper in axial direction in mm.

6. The botulinum toxin prefilled syringe system of claim 1 , wherein the inner surface of the syringe barrel is siliconized.

7. The botulinum toxin prefilled syringe system of claim 1 , wherein the plunger stopper is of an elastomeric material.

8. The botulinum toxin prefilled syringe system of claim 7 , wherein

(i) the elastomeric material is a synthetic rubber selected from the group consisting of isoprene rubber, neoprene rubber, butadiene rubber, butyl rubber, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polysulfide elastomers, urethane rubbers, and ethylene-propylene elastomers, or

(ii) the plunger stopper further has a coating on at least a portion of the plunger stopper such that the liquid botulinum toxin formulation contacts only said coating during storage and/or injection, and the coating on at least a portion of the plunger stopper is a fluoropolymer coating, a crosslinked silicone coating, or a coating consisting of an outer crosslinked silicone coating layered on a fluoropolymer coating, or

(iii) the elastomeric material is defined as in (i) and the coating is defined as in (ii).

9. The botulinum toxin prefilled syringe system of claim 7 , wherein the elastomeric material is a halogenated butyl rubber.

10. The botulinum toxin prefilled syringe system of claim 1 , wherein the outlet engaging portion of the closure device is of an elastomeric material.

11. The botulinum toxin prefilled syringe system of claim 10 , wherein

(i) the elastomeric material is a synthetic rubber selected from the group consisting of isoprene rubber, neoprene rubber, butadiene rubber, butyl rubber, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polysulfide elastomers, urethane rubbers, and ethylene-propylene elastomers, or

(ii) the outlet engaging portion of the closure device further has a coating on an outer surface thereof such that the liquid botulinum toxin formulation contacts only said coating during storage and/or injection, and the coating is a fluoropolymer coating, a crosslinked silicone coating, or a coating consisting of an outer crosslinked silicone coating layered on a fluoropolymer coating, or

(iii) the elastomeric material is defined as in (i) and the coating is defined as in (ii).

12. The botulinum toxin prefilled syringe system of claim 10 , wherein the elastomeric material is a styrene-butadiene copolymer, a butyl rubber, a halogenated butyl rubber, or a butyl rubber-isoprene rubber blend.

13. The botulinum toxin prefilled syringe system of claim 1 , wherein botulinum toxin activity is not reduced by more than 25%, relative to an initial botulinum toxin activity, upon storage of the botulinum toxin prefilled syringe system for 12 months at 5° C. or 25° C.

14. A kit comprising the botulinum toxin prefilled syringe system according to claim 1 .

15. The botulinum toxin prefilled syringe system of claim 1 , wherein the plurality of annular ribs of the plunger stopper is three to four.

16. The botulinum toxin prefilled syringe system of claim 1 , wherein the inner surface of the syringe barrel is spray-siliconized or baked-on siliconized.

17. The botulinum toxin prefilled syringe system of claim 1 , wherein the normalized maximum gliding force is 12 N or less, as measured at a temperature of 20° C. using a 32 G×½″ needle and a displacement speed of 100 mm/min.

18. The botulinum toxin prefilled syringe system of claim 1 , wherein the normalized maximum gliding force is 8 N or less, as measured at a temperature of 20° C. using a 32 G×½″ needle and a displacement speed of 100 mm/min.

19. The botulinum toxin prefilled syringe system of claim 1 , wherein the normalized break loose force is 5 N or less, as measured at a temperature of 20° C. using a 32 G×½″ needle and a displacement speed of 100 mm/min.

20. The botulinum toxin prefilled syringe system of claim 1 , wherein

the normalized maximum gliding force is 15 N or less after storage of the botulinum toxin prefilled syringe system for 12 to 24 months at 2 to 8° C. or for 12 to 24 months at 25° C., as measured at a temperature of 20° C. using a 32 G×½″ needle and a displacement speed of 100 mm/min, and

the normalized break loose force is 8 N or less after storage of the botulinum toxin prefilled syringe system for 12 to 24 months at 2 to 8° C. or for 12 to 24 months at 25° C., as measured at a temperature of 20° C. using a 32 G×½″ needle and a displacement speed of 100 mm/min.