Multi Dose Cartridge For Homogeneous Liquid Medicament Solution
Field of the invention
This invention relates container or cartridge made up of glass for liquid medicament solution, especially for any kind of homogeneous liquid varieties that is to say. The volume of such container or cartridge is sufficient for holding 10ml to 25ml formulation of said medicament comfortably within the liquid filled interior of cartridge body. Such container for homogeneous liquid medicament solution with sealing piston suited for use as multi dose cartridges for any kind of drug delivery system having piston operating mechanism.
Back ground of the invention
It is known to provide various available medicament suspension cartridges or ampoule formed from a barrel, suitably a glass able to hold 3ml to 5 ml within the hollow interior glass tube, sealed at one end by a piston and terminating at the other end by round or rectangular hub like structure sealed by a cap. In use the cartridge is placed in pen like devices provided with a mechanical drive member assembly which advances distally in the forward direction by doing some mechanical operation on the system to cause administration of pre selected dose to be ejected through the hyperdermic needle which is attached at the cap end so as to pierce the cap and establish communication with the cartridge interior. Such medicament suspension cartridges with one or more mixing elements is described in EP- 0235691.
In the marketed versions, containing insulin crystal suspensions, include one or more glass or metal spheres which, when the cartridge is shaken or inverted several times, are free to move and roll within the cartridge, thereby facilitating the mixing of the suspension. The drawbacks in the case of disperse systems such as medicament suspensions is that mechanical problem exists during suspension due to crystal settling and also incorrect dosage is cause to be administered due to such crystal settling. Such incorrect dosages are particularly critical when the medicament is a highly active medicament of narrow therapeutic range, such as for example insulin.
Hence need exists for the more economical and less medical waste multi dose cartridge of very long term use i.e. is of sufficient high volume and of homogeneous liquid form instead of medicament suspensions. The present invention fullfills all the requirement and over comes all aforesaid drawbacks and provides multi dose glass cartridge of having 10ml to 25ml volume for liquid medicaments, aspecially homogeneous solution so that no mixing element is required for mixing suspension and thereby aforesaid critical or dangerous consequences are prevented. Such cartridge can be used for long term as it has been constructed to hold liquid up to 25ml formulation. As the glass cartridge can able to hold 25ml of drug contents minimum 12 doses can be charged; this is the thing which makes it different from other existing cartridge.
Various conventional cartridges or ampoules available in the market use 22 grams of glass for 20 ml formulation but present multi dose glass cartridge of sufficient high volume upto 25 ml. (For example the glass cartridge of sufficient high volume upto 20 ml uses only 8 gm). And thereby provides direct 175 % saving of glass materials than the conventional cartridges or ampoules.
Object of the invention
The main object of the invention is to provide multi dose cartridge of sufficient high volume which can enable very long term usage of cartridge and on the other hand comfortably to fit inside the multi dose pen like drug delivery system. This invention also object to provide use of homogeneous liquid medicament solution of 100% sterile instead of liquid medicament suspensions and which is filled inside the liquid hollow interior of glass cartridge which does not react with the outer glass materials during long term use.
Summary of the invention
The present invention discloses construction of long multi dose glass cartridge for homogeneous liquid medicament solution which is closed by tubular hub at one end and sealed with sealing piston at the interior surface of the other proximal end of the container. Such sealing piston or stopper forms fluid tight mechanism with the liquid filled interior of the glass cartridge to advance distally to push the medicament to eject the later through hyperdermic needle. Pushing mechanism of the sealing piston is engaged by pushing the piston operating mechanism of the multi dose drug delivery device in which the cartridge has been loaded for administration of preset dose that has been selected by the preset mechanical drive assembly device. On the other hand the cartridge of this volume are designed first time to fit comfortably inside the pen like drug delivery system with a different purpose of reducing cost as well as medical waste. Detail Description of the Invention
Perspective longitudinal cross sectional view of cylindrical cartridge constructed in accordance with the present invention is diagrammatically shown in fig.l, as foregoing description can be technically and mechanically understood with the help of it.
A liquid holding container or cartridge (7) is formed of three parts such as tubular hub (1) at the distal end, proximally open ended cylindrical cartridge body (3) being the main part of the container and reduced diameter neck region (2). The whole container or cartridge (8) is made up of glass materials. Homogeneous liquid medicament is filled inside the hollow interior glass barrel of cartridge body (3).
The long cylindrical cartridge body (3) distally follows reduced diameter neck region (2) which further distally follows tubular hub (1) at the distal end of the container (7). Such hub is formed by covering apertured alluminum cap (4) and synthetic rubber membrane or septum (5) inside the covering. When the container (7) is loaded into one of the commercially available drug delivery device or pen and the hyperdermic needle is mounted at the distal end of the hub (1), needle pierces into the said apertured cap and thereby communicates with the liquid filled interior of glass barrel of cartridge body (3). Hence the whole length and volume of the container is such that it can hold upto 25ml of liquid formulation comfortably within the liquid filled interior of glass barrel of cylindrical cartridge body (3).
At the proximal open end of the cartridge body unidirectional rubber piston (6) or stopper of suitable shape is sealed at the inner surface of the cartridge. Such stopper forms fluid tight engagement with the inner liquid filled interior of glass barrel of cartridge body (3) and which is free to move in the axial distal direction inside the inner surface of the glass barrel. In use when such cartridge with sealing piston (6) is loaded in the drug delivery system or device, during piston operating mechanism of the device the piston assembly of device pushes the sealing piston or stopper (6) of fluid tight engagement with the glass barrel in the distal or forward direction to administer or eject the desired amount of preset dose that has been selected by the preset dose mechanism of the device. As the present cartridge holds large volume (25 ml) of medicament several doses can be preset and subsequently administered for long term with 100% sterility.