DESC:Field of the invention
The present invention relates to a novel drug delivery device for delivering a drug to the human body.

Background of the invention
In some therapy areas the tendency of a patient to remain to the prescribed therapy is mainly dependent on the ease of the specific treatment procedure. For instance, people suffering from diabetes are often needed to take multiple daily injections. Such people are less prone to accept a treatment that intervenes too much with their normal life and do not like to be reminded of their disease constantly. Such patient groups look forward to delivery devices that are easily operable and in addition provide accurate dosing.
Over the years, various types of injection devices have been described. However, pen-type injection devices have attracted special attention above all other types of injection devices. Mainly two different types of pen systems are available, namely with replaceable cartridges and with a non-replaceable cartridge.
There are many parameters involved with an efficient injection pen. One such parameter is the setting of a dose. It must be easy to set a dose and easy to read the set dose. It must be possible to cancel or change a wrongly set dose with a minimum of trouble and the dose setting must return to zero after injecting the dose. Another parameter is limiting the set dose. When a drug is injected into the human body, it may have serious or even lethal consequences if the injected dose exceeds the set dose. So, it is important that the syringe devices comprises means for limiting release to the set dose.

Certain drug delivery devices are available in prior art. For instance, US8608709 discloses an injection device for dispensing set doses of a drug from a reservoir to a subject. The injection device comprises a dose setting member which is screwed out from the housing to set a dose and pushed axially back to the housing in order to expel the set dose. A scale drum is axially and coupled to the dose setting member and is immovable, such that the scale drum is rotated up a thread when the dose setting member is rotated to set a dose. When the dose setting member is pushed axially back to its initial position to inject the set dose, the scale drum is released from its non-rotatable connection in order to allow the scale drum to rotate down the thread and back to its zero position.
EP2047878 discloses an injection pen for delivering a drug to the human body preferably in a subcutaneous manner and especially to a user energized injection pen having a rotatable scale drum.

US2009/0137964 discloses an injection device with an End-of-Content mechanism which comprises a track and a track follower each coupled directly or indirectly to the housing and the dose setting member.

However, there are certain disadvantages associated with various devices in the prior art in terms of accuracy of dosing or compatibility of the user and therefore, there is a need of a new device with convenient dose setting mechanism for the user. In addition there are also certain complications in the manufacture of said devices which due to the number of change parts also call for extensive tooling and controls.

OBJECT OF THE INVENTION
An object of the invention is to provide a novel drug delivery device.

BRIEF DESCRIPTION OF DRAWINGS
Figure 1 depicts the perspective view of the drug delivery device of the present invention depicted as (5000) and in continuation (8000);
Figure 2 is a schematic representation of an overcap (100) and a cartridge holder (200), a narrow end (210), a broader end (220), windows (230), (240) and (250);
Figure 3 is a schematic representation of a flange (300) and a cartridge lock (400), a threaded rod (500) and a click sleeve (600);
Figure 4 is a schematic representation of a housing (700), a window (710) and a housing insert (800);
Figure 5 is a schematic representation of a dose sleeve (900) and a dose lock nut (1000), a dose lock sleeve (1100), a finger grip (1110).
Figure 6 is a schematic representation of a click ring (1200) and a dose bottom (1300).
Figure 7 is a schematic representation of the dose sleeve (900), a stopper or projection (910) and the dose lock nut (1000).
Figure 8 depicts the housing insert (800), dose sleeve (900) and the stopper or projection (910) on dose sleeve (900) the dose lock nut (1000).
Figure 9 depicts the position of stopper or projection (910) in screwing position of the dose sleeve (900) on to housing insert (800).
Figure 10 depicts the dose sleeve (900) and stopper or projection (910) at ready to use position.
Figure 11 depicts the dose sleeve (900) ready for use at next door cycle.

BRIEF DESCRIPTION OF THE INVENTION
The device in the Figure 1 comprises mainly of two parts disclosed herein at the accompanying figures (5000) and (8000). The device consists of an over cap (100) (Fig. 2), a cartridge holder (200) (Fig. 2) comprises of a narrow end (210) and a broader end (220) with three windows 230, 240 and 250, the flange (300) (Fig.3), a cartridge lock (400) (Fig. 3), a threaded rod (500) (Fig. 3), a click sleeve (600) (Fig. 3), housing (700) (Fig. 4), a window (710) (Fig. 4), housing insert (800) (Fig. 4), a dose sleeve (900) (Fig. 5), a projection or stopper (910) (Fig. 7), a dose lock nut (1000) (Fig. 5), a dose lock sleeve (1100) (Fig. 5), a finger grip (1110) (Fig. 5), a click ring (1200) (Fig. 6), a dose bottom (1300) (fig. 6).

From Figures, the perspective view of the device (5000) shows the over cap (100), which is placed over the cartridge holder (200). The cartridge holder (200) comprises of a narrow end (210) and a broader end (220). The narrow end (210) is set with threaded flutings, which are capable of being connected to the cartridge comprising the drug or any other devices comprising the drug. The cartridge holder comprises of three windows (230), (240) and (250), which may be used by the user to examine the amount of the dose remaining in the cartridge. The device also has a housing (700) within which is the housing insert (800). The housing (700) with a window (710) has a threaded rod (500) which in turn is placed inside a click sleeve (600) and is attached distally to a flange (300) and to a cartridge lock (400). The threaded rod (500) placed inside the click sleeve (600), is further set within the dose sleeve (900). The rotation of the dose sleeve (900) is facilitated by a cam module to the dose lock nut (1000) and dose lock sleeve (1100), which comprises of a finger grip (1110), which engages with the dose lock nut (1100). The dose sleeve (900) is proximally attached to a click ring (1200) and a dose bottom (1300). The dose sleeve (900) further comprises a projection or stopper (910) (Fig. 9), the projection is such that when the user sets the dose, the projection is locked with the housing insert (800) further aided by the dose lock nut (1000).

DETAILED DESCRIPTION OF THE INVENTION
The device in the Figure 1 comprises mainly of two parts disclosed herein at the accompanying figures (5000) and (8000).

The device consists of an over cap (100) (Fig. 2), a cartridge holder (200) (Fig. 2) comprises of a narrow end (210) and a broader end (220) with three windows (230), (240) and (250), the flange (300) (Fig.3), a cartridge lock (400) (Fig. 3), a threaded rod (500) (Fig. 3), a click sleeve (600) (Fig. 3), housing (700) (Fig. 4), a window (710) (Fig. 4), housing insert (800) (Fig. 4), a dose sleeve (900) (Fig. 5), a projection or stopper (910) (Fig. 7), a dose lock nut (1000) (Fig. 5), a dose lock sleeve (1100) (Fig. 5), a finger grip (1110) (Fig. 5),, a click ring (1200) (Fig. 6), a dose bottom (1300) (fig. 6).

From Figures, the perspective view of the device (5000) shows the over cap (100), which is placed over the cartridge holder (200). The cartridge holder (200) comprises of a narrow end (210) and a broader end (220). The narrow end (210) is set with threaded flutings, which are capable of being connected to the cartridge ((111), not depicted in figures) comprising the drug or any other devices comprising the drug. The cartridge holder comprises of three windows (230), (240) and (250), which may be used by the user to examine the amount of the dose remaining in the cartridge. The device also has a housing (700) within which is the housing insert (800). The housing (700) with a window (710) has a threaded rod (500) which in turn is placed inside a click sleeve (600) and is attached distally to a flange (300) and to a cartridge lock (400). The threaded rod (500) placed inside the click sleeve (600), is further set within the dose sleeve (900). The rotation of the dose sleeve (900) is facilitated by a cam module to the dose lock nut (1000) and dose lock sleeve (1100), which comprises of a finger grip (1110), which engages with the dose lock nut (1000). The dose sleeve (900) is proximally attached to a click ring (1200) and a dose bottom (1300). The dose sleeve (900) further comprises a projection or stopper (910) (Fig. 9), the projection is such that when the user sets the dose, the projection is locked with the housing insert (800) further aided by the dose lock nut (1000).

The device present invention is such that it does not allow for a dose to be set, which is higher than the medicament contained in the cartridge. Further the present invention is advantageous in that it does not allow the user to change the dose, when a dose is already set without removing the cartridge.

The device of the present invention is such that dose sleeve (900) is designed in a specific manner that it comprises of several flutings, the distance between the flutings calibrated in such a manner such that it is designed to provide a specific dose to the user in a calibrated manner. In addition and most critically for this device to work the dose sleeve is incorporated with projection that enables the locking of dose at a specified pre-defined dose. This projection (910) works closely with the housing insert (800), the dose lock sleeve (1100) and the dose lock nut (1000) to ensure that the dosing is delivered in an accurate manner and also prevents the administration of the dosage if the dose is less than that of administrable dose; and any change in dose, once the dose is pre-set.

The dose is regulated by a threaded rod (500) placed inside the click sleeve (600). The dose sleeve (900) is capable of rotation in a clockwise manner to set the dose and in an anti-clockwise manner to change the already set dose. Once the dose is set, the dose may be administered by pressing the dose bottom (1300) in a longitudinal manner parallel to the axis of the injection. Accidental delivery of over dose is prevented by the specially designed flexible projection and its opposition with the housing insert (800). Once the drug cartridge is placed inside the cartridge holder (200) the housing insert is slid into its home position over the dose sleeve (900). This slide is made possible by the unidirectional flexion of the projection (910) on the dose sleeve. Once the housing insert (800) is kept at the home position proximally towards the dose bottom (1300) and the click ring (1200), the pen is “active” for delivery of the drug product in the cartridge and an overdose is prevented by the opposition of the projection (910) and the housing insert (800). In others words the dose sleeve cannot move beyond the set dose. Further, the flange (300) and the cartridge lock (400) ensures that once the dose is set, it can be changed only by anti-clockwise rotation of the dose sleeve (900) and remains constant during delivery.

An over dose by the device of the present invention may be prevented by the specially designed flexible projection and its opposition with the housing insert (800) and wherein flange (300) and the cartridge lock (400) prevents clockwise rotation of the dose sleeve (900).

The novel device of the present invention is characterized in the fact that the present invention does not comprise of a gear box but the dosing is regulated by use of the dose sleeve (900) specifically designed with a unique projection that greatly simplifies the delivery a predefined dose in conjunction with the housing insert (800), the dose lock nut (1000) and dose lock sleeve (1100).

In addition this dose sleeve is unique in that it may be constructed with thermochromic materials in order to make the dose sleeve temperature and light sensitive. The thermochromic materials in the dose sleeve enable a change in the colour of the dose sleeve if the store temperature of the device moves beyond the recommended store temperature. This change in color will serve as warning for the consumer before the use of the product housed inside the cartridge. While thermochromic materials have been used before with such products the use of such materials in the dose sleeve is critical because temperature studies have shown that the pen device part that closely depicts the store temperature of the product is the dose sleeve. While ideally if thermochromic material could be incorporated into the drug cartridge, it would present the closest temperature range data that the drug product is subjected to. However the presence of the thermochromics materials in the cartridge might present certain drug interaction challenges the next best alternative for the incorporation of such materials would be the dose sleeve. This is the part that remains enclosed as the drug product in the protective housing and hence presents more relevant information for the user. Additionally since the dose sleeve is to be used prior to the use of the product this will also serve as a visual indication for acceptable use of the product.

In addition to the use of the thermochromic materials in the dose sleeve this dose sleeve is also further incorporated with a fluorescence dye that indicates the dose marking. This fluorescence dye provides the user a better visual indicator indication of the dose in especially in low light conditions thus improving further accuracy and safety to the user.

This incorporation of two very different chemical materials for widely different properties- one for thermochromism that provides a visual indication of the temperature range and the other a fluorescence dye for the visual indication in low light conditions requires the dose sleeve to be injection moulded with the precision that the object of this patent also covers.
The syringe in Figure 1, comprises of an over cap (100), to cover the delivery portion. The housing insert (800), comprises the housing (700), the housing houses the cartridge holder (200) and is designed to fit into housing insert (800). The housing insert (800) and the cartridge holder (200) are amenable for mounting the cartridge comprising the medicament of choice. The dose may be set by using the dose sleeve (900). The dose sleeve (900) is provided with flutings, which is attached to a dose lock nut (1100), which comprises of a finger grip (1110), which engages with the dose lock nut (1100). The dose sleeve (900) comprises of the dose lock nut (1000) at one end, which is attached to a click ring (1200) and the dose bottom (1300). The click ring (1200) prevents any rotational movement of the dosing device and the dose bottom (1300) is amenable for compression along the longitudinal axis to deliver the desired dose by the user. The dosing assembly includes the dose sleeve (900), the dose lock nut (1000), the click ring (1200), the dose bottom (1300), the threaded rod (500) and the click sleeve (600). The dosing assembly serves to set the dose, deliver the set dose, prevent the change in the set dose during administration and prevents setting of a dose which is greater than the amount of the drug present in the device.

Figure 2 depicts a over cap (100), which may be placed over the device when the user is not using the device, which prevents needle prick injuries and also prevents the device from any external infections. The cartridge holder (200) comprises of a narrow end (210) and a broader end (220). The narrow end (210) is set with threaded flutings, which are capable of being connected to the cartridge comprising the drug or any other devices comprising the drug. The cartridge holder comprises of three windows 230, 240 and 250, which may be used by the user to examine the amount of the dose remaining in the cartridge. The broad end of the cartridge holder (220) is amenable to being placed in the housing insert (800). The housing insert (800) is designed to receive the cartridge holder (200) at the end (220). The hosing insert (800) and the cartridge holder may be connected by male and female connectors or by any other locking mechanism. As seen in Figure 1 (8000), the threaded rod (500) comprise in the click sleeve (600) is placed in the housing (700) in a parallel axis to the dose sleeve (900). The threaded rod (500) is calibrated to the dose, which may be seen in the dose setting window. The dose setting window is provided with an arrow corresponding to the set dose.

Figure 3 disclose the flange (300), which connects the housing insert (800), connected to the cartridge holder (200) at one end to the cartridge lock (400) at the other end. The cartridge lock (400) is connected to the threaded rod (500) placed in the click sleeve (600). The threaded rod is a dose setting member, which is cylindrical in nature and on its walls contains helical trackings. The helical tracking is designed to cooperate with the helical inner ridge in the click sleeve (600) (not shown in the figure 3) so that when the dose setting member is screwed clockwise the dose sleeve (900) moves out of the device and the set dose is shown to the window of the housing (700) corresponding to an arrow so that the user can determine the said dose during dose setting rotation made clockwise the dose setting member is free to rotate. After setting the dose, the dose lock nut (1000) and the dose lock sleeve (1100) prevents the change in the dose unless the user rotates the member in an anti-clockwise manner. However, longitudinal movement along the axis is freely allowed along the click sleeve (600) in order to deliver already set dose. The housing (700) disclosed at Figure 4 is set to hold the dosing assembly, the housing assembly (700) comprises of a window (710), which enables the user to see the markings and set the dose. The dose may be set by matching the markings with the arrow in the housing insert (800) holds the housing in position and attaches the housing to the cartridge lock (400) through the flange (300). The cartridge lock (400) on pressing inward by the user is capable of moving the complete dosing assembly in the longitudinal axis and delivering the dose.

To set a dose, the finger grip (1110) of the dose sleeve (900) is gripped and the dose assembly comprising of the dose sleeve (900) and the dose lock nut (1100) is rotated clockwise until the arrow point set the desired dose on the scale. This rotation will make the parts of the dose setting element and the dose lock nut (1100) ride over each other. If the dose lock sleeve (1100) is rotated in the clockwise direction to set the dose, the dose lock sleeve (1100) will cause the clock sleeve (600) comprising the threaded rod (500) to increase the dose by setting a torque in the said direction. The torque generated prevents the change of the said dose unless the dose sleeve (900) is rotated in the anti-clockwise manner. However, the movement in the longitudinal axis is unimpeded and allows the dose to be delivered when the dose bottom ring (1300) and the click ring (1200) is pressed.

The dose sleeve (900) is provided with flutings in such a manner to allow the dose lock sleeve (1300) and the dosing assembly to rotate in both directions (clockwise and anti-clockwise) by which the threaded rod (500) contained in the click sleeve (600) may be advanced or retracted in the cartridge holder (200). The dose sleeve (900) is set in such a manner that it does not have any gear box or gear wheel assembly in contrast to the prior art devices.

The present invention discloses a novel system of dose setting in contrast to the prior art devices. The present invention uses a simple and an economic design to ensure accurate setting of the dose and 100% delivery of the preset dose. This is achieved by the use of a novel design of the dose sleeve (900) disclosed at Figure 7 of the invention. The dose sleeve (900) comprises a projection or stopper (910), the projection is such that when the user sets the dose, the projection is locked with the housing insert (800) (Fig. 8) further aided by the dose lock nut (1000). The locking ensures that once the dose is set, it cannot be changed unless a torque is set in the opposite direction. However, enables the delivery of the dose. The dose sleeve (900) in conjunction with the housing insert (800), dose lock nut (1000) through the projection or stopper (910) is depicted at Figure 8. However, the flutings are placed in such a manner that the device is capable of delivering accurate dose to the user without complicated mechanisms.

Without being limited by theory, it is submitted that the design and the mechanism of the device is simplistic, accurate, economical and capable of providing a long life to the user.

It may be understood by a person skilled in the art that the present invention is accompanied by figures. The figures form a part of the invention. The figures encompass the embodiment as illustrated in each figure. It is understood by a person skilled in the art that other variations of the device and combinations thereof are envisaged within the scope of the invention. The method of performing the invention using the device is also envisaged within the scope of the said invention.
In another embodiment, the device of the present invention comprises of a dose setting mechanism wherein the dose may be set according to the present invention and an injection mechanism, wherein the set dose may be delivered in accordance with the present invention.
The present invention discloses an injection device as disclosed hereinabove along with the accompanying drawings having a housing (700) accommodating a cartridge containing medicine sufficient for a number of dosed injections, whereby doses are injected by advancing a rod forward inside the cartridge, the injection device comprising:
i. a dose setting and injection mechanism,
ii. a dose setting member coupled to the dose setting and injection mechanism for setting up a dose to be injected,
iii. an injection button coupled to the dose setting and injecting mechanism and by which the dose setting and injection mechanism can be activated for advancing the rod forward in order to press out the set dose through a conduit connected to the cartridge, and
iv. an arrangement for preventing the dose setting member to be set to a dose larger than the medicament remaining in the cartridge.

Example: Evaluation of the device of the present invention
A study was conducted following to evaluate the device of the present invention, wherein 15 pharmacists were provided with 250mcg of device, for a total of eight devices per pharmacist. The pharmacists were assessed in their ability to select a correct dose (dose setting) and locking the same on the plunger. Results showed that six pharmacists failed to select a correct dose collar on ten devices. Three pharmacists failed to distinguish the color coding of the locking units, which correspond to a common length. Five pharmacists succeeded in locking the collar on the plunger but with a difficulty. One pharmacist left three syringes unlocked.

The results obtained from the use of device of the present invention, with 15 pharmacists each given the device of the present invention comprising a medicament of 250mcg strength for a total of 8 devices per pharmacist, and the results are presented at Table 1.

Table 1: Evaluation of the device of the present invention
S.No Parameter Success Success with difficulty
1 Fixing the dose setting mechanism/nut 13 2
2 Selecting the right dose 14 1 pharmacists
Misreading of the desired dose through lens in one or more devices

From the results observed in Table 1, it is evident that the devices of the present invention provide surprisingly better results than the prior art devices. The pharmacist were able to fix the locking nut (dose setting mechanism) to the cartridge and set the appropriate dosage more consistently. Thus, the device of the present invention are found to be superior to the prior art devices. ,CLAIMS:1. A novel drug delivery device comprising the parts of;
an over cap (100), a cartridge holder (200) having a narrow end (210) and a broad end (220), with three windows (230), (240) and (250), a flange (300), a cartridge lock (400), a threaded rod (500), a click sleeve (600), housing (700), a window (710), housing insert (800), a dose sleeve (900), a projection or stopper (910), a dose lock nut (1000), a dose lock sleeve (1100), a finger grip (1110), a click ring (1200), a dose bottom (1300); wherein, the dose sleeve (900) further comprises a projection or stopper (910), the projection is such that when the user sets the dose, the projection is locked with the housing insert (800) further aided by the dose lock nut (1000).

2. A device as claimed in claim 1, wherein, the over cap (100), is placed over the cartridge holder (200), comprising a narrow end (210) with threaded flutings, a broader end (220), capable of being connected to the cartridge comprising the drug or any other devices comprising the drug, and comprising three windows (230), (240) and (250), used to examine the amount of the dose remaining in the cartridge.

3. A device as claimed in claim 1, wherein, the housing (700), is placed within the housing insert (800), comprises a window (710), a threaded rod (500), placed inside a click sleeve (600), attached distally to a flange (300) and to a cartridge lock (400) is further set within the dose sleeve (900).

4. A device as claimed in claim 1, wherein, the rotation of dose sleeve (900) is facilitated by a cam module to the dose lock nut (1000) and dose lock sleeve (1100), which engages with the dose lock nut (1000), and the dose sleeve (900) is proximally attached to a click ring (1200) and a dose bottom (1300).

5. A device as claimed in claim 1, wherein, the dose sleeve (900) further comprises a projection or stopper (910), wherein, the projection is such that when the user sets the dose, the projection is locked with the housing insert (800) further aided by the dose lock nut (1000).

6. A device as claimed in claim 1, wherein, the dose sleeve (900) comprises several flutings, and wherein the distance between the flutings calibrated to provide a specific dose and wherein, dose is regulated by a threaded rod (500) placed inside the click sleeve (600).

7. A device as claimed in claim 1, wherein, the dose sleeve (900) is rotated in a clockwise manner to set the dose and in an anti-clockwise manner to change the already set dose and dose is administered by pressing the dose bottom (1300) in a longitudinal manner parallel to the axis of the injection.

8. A device as claimed in claim 1, wherein, over dose is prevented by the specially designed flexible projection and its opposition with the housing insert (800) and wherein flange (300) and the cartridge lock (400) prevents clockwise rotation of the dose sleeve (900).

9. A device as claimed in claim 1, comprising, a
i. a dose setting and injection mechanism,
ii. a dose setting member coupled to the dose setting and injection mechanism for setting up a dose to be injected,
iii. an injection button coupled to the dose setting and injecting mechanism and by which the dose setting and injection mechanism can be activated for advancing the rod forward in order to press out the set dose through a conduit connected to the cartridge, and
iv. an arrangement for preventing the dose setting member to be set to a dose larger than the medicament remaining in the cartridge,

10. A device as claimed in claim 1, wherein, the dose sleeve is constructed with thermochromic materials.

11. A device as claimed in claim along with accompanied drawings.