Lubricant coating and medical injection device comprising such a coating
The invention relates to a lubricant coating ( 5 ) for a medical injection device ( 1 ), comprising successively: —a bottom layer ( 50 ) in contact with the medical device surface ( 21 ) of the container to be lubricated, comprising a mixture of cross-linked and non-cross-linked poly-(dimethylsiloxane), —an intermediate layer ( 51 ) consisting essentially of oxidized poly-(dimethylsiloxane) and having a thickness comprised between 10 and 30 nm and, —a top layer ( 52 ) consisting essentially of non-cross-linked poly-(dimethylsiloxane) and having a thickness of at most 2 nm. The invention also relates to a medical injection device comprising such a lubricant coating, and a manufacturing process for said coating.
1. A medical injection device, comprising:
a barrel comprising a proximal end, a distal end, a sidewall therebetween defining a reservoir, and a stopper in gliding engagement within the barrel, the sidewall having an inner surface facing the reservoir and at least partially covered by a lubricant-coating,
wherein the lubricant coating comprises:
a bottom layer in contact with the inner surface of the sidewall of the barrel, comprising a mixture of cross-linked and non-cross-linked poly-(dimethylsiloxane);
an intermediate layer consisting essentially of oxidized poly-(dimethylsiloxane); and
a top layer consisting essentially of non-cross-linked poly-(dimethylsiloxane),
wherein the intermediate layer is porous, thereby allowing communication between the bottom layer and the top layer.
2. The medical injection device according to claim 1 , wherein the barrel is made of plastic.
3. The medical injection device according to claim 1 , wherein the barrel is made of glass.
4. The medical injection device according to claim 1 , wherein a particle level generated inside the device when filled with a solution of a mixture of 10 g/L of Phosphate Buffered Saline and 2.13 mg/L of Polysorbate 80 in Water filtered with a 0.22 microns filter, is less than 2.11 particles per mm 2 of coating when measured by light obscuration and/or less than 10.56 particles per mm 2 of coating when measured by flow microscopy.
5. The medical injection device according to claim 1 , wherein the lubricant coating has a thickness in a range of 90 nm to 400 nm.
6. The medical injection device according to claim 1 , wherein the bottom layer is a gel.
7. The medical injection device according to claim 1 , wherein the thickness of the bottom layer is in a range of 58 nm to 388 nm.
8. The medical injection device according to claim 1 , wherein the top layer has a thickness of at most 2 nm.
9. The medical injection device according to claim 1 , wherein the distal end of the barrel comprises a luer connection or a needle.
10. The medical injection device according to claim 1 , wherein the barrel has an internal volume of 1 ml and a diameter of 6.35 mm.
11. The medical injection device according to claim 10 , wherein a weight of the lubricant coating is in a range of 0.1 mg to 0.4 mg.
12. The medical injection device according to claim 1 , wherein the thickness of the intermediate layer is in a range of 10 nm to 30 nm.
13. The medical injection device according to claim 12 , wherein the thickness of the intermediate layer is in a range of 15 nm to 25 nm.
14. The medical injection device according to claim 1 , wherein a gliding force of the stopper within the barrel is in a range of 1 N to 8 N.
15. The medical injection device according to claim 14 , wherein the gliding force of the stopper within the barrel is in the range of 3 N to 6 N.
16. The medical injection device according to claim 1 , wherein a chemical formula of the oxidized poly-(dimethylsiloxane) of the intermediate layer is:
[SiO(CH 3 ) 2-x (OH) x ] n ,
where x ranges from 0.2 to 1.5 and n is an integer.
17. The medical injection device according to claim 16 , wherein x ranges from 0.6 to 1.
18. The medical injection device according to claim 16 , wherein n ranges from 70 to 100.
19. A process for manufacturing a medical injection device comprising a barrel comprising a proximal end, a distal end, a sidewall therebetween defining a reservoir, and a stopper in gliding engagement within the barrel, the sidewall having an inner surface facing the reservoir, the method comprising:
depositing a layer of poly-(dimethylsiloxane) on the inner surface of the sidewall of the barrel, the thickness of said layer being in a range of 90 nm to 400 nm; and
exposing said layer to an oxidizing plasma under vacuum and in an atmosphere comprising oxygen and argon, so as to form a lubricant coating by oxidizing and cross-linking at least part of the poly-(dimethylsiloxane),
wherein the lubricant coating comprises:
a bottom layer in contact with the inner surface of the sidewall of the barrel, comprising a mixture of cross-linked and non-cross-linked poly-(dimethylsiloxane);
an intermediate layer consisting essentially of oxidized poly-(dimethylsiloxane); and
a top layer consisting essentially of non-cross-linked poly-(dimethylsiloxane)
wherein the intermediate layer is porous, thereby allowing communication between the bottom layer and the top layer.
20. The process according to claim 19 , wherein the vacuum ranges from 10 mTorr to 100 mTorr.