Claims:
1. A disposable insulin administration device for accurate administration of the pre-set dose of insulin, wherein the disposable insulin administration device comprises of unidirectional coupling consisting of ratchet and pawl mechanism configured for producing click sound while setting of the dose, wherein the disposable insulin administration device of comprises of:

a. a bottom barrel provided with internal threads which are engaged with a drive tube;
b. a drive tube provided with indicia deployed along helical path, for indicating the set dose and produces a clicking sound while setting the dose;
c. a press knob disposed at the top end of drive tube, wherein, when pressure is applied the press knob, the device injects the dose;
d. a ratchet abutting the press knob, wherein ratchet produces a clicking sound while setting the dose;
e. a sleeve engaged with the ratchet on the top end, wherein the sleeve is configured for arresting rotation of the piston holder and activating its linear motion and produces a clicking sound while setting the dose;
f. a piston holder at least partially encased in the sleeve;
g. a piston which is intermeshed with the piston holder, wherein the piston is designed to achieve rotary and linear motion while injecting insulin;
h. a cartridge holder cap engaging with the bottom end of piston, and
i. a dosing knob abutting the cartridge holder cap and is engaged with the piston, wherein said dosing knob is configured to transfer the pressure applied on piston to the liquid present inside an insulin cartridge for expressing the liquid out of the cartridge,

wherein, the drive tube is configured to automatically return to zero position after administration of pre-set dose.

2. The disposable insulin administration device of claim 1, wherein the disposable insulin administration device further comprises of:
a. an insulin cartridge, wherein the cartridge is irremovably fitted in the insulin administration device of the invention, and
b. a disposable hypodermic needle.

3. Method of operation of disposable insulin administration device of Claim 1, wherein the method for arming the device comprisesof:
a) removing the top cap from the syringe section of the insulin administration device;
b) screwing in or pushing a new disposable needle, such that the back end of the needle passes through a thin rubber stopper on the tip of the syringe section, entering the cartridge holderholding the insulin cartridge;
c) Setting the desired dose by turning the drive tube clockwise, and
d) Pressing the press knob to deliver the dose set.
, Description:Field of Invention:
The invention as disclosed herein relates to an insulin administration device. More particularly, the invention relates to a disposable insulin administration device which delivers an accurate dose of insulin.

Background of Invention:
Diabetes is fast gaining the status of a potential epidemic in India, with more than 62 million individuals currently diagnosed with the disease. The treatment currently available for diabetes includes diet control and administration of insulin, a peptide responsible for controlling blood sugar. Insulin administration could be carried out by traditional syringes or by using modern insulin administration devices.

Insulin administration devices, such as insulin pen devices, have several advantages over the traditional vial-and-syringe method of insulin delivery, including improved patient satisfaction and adherence, greater ease of use, superior accuracy for delivering small doses of insulin, greater social acceptability, and less reported injection pain.

Two types of insulin pens are available in market, disposable insulin pens and reusable insulin pens. The disposable insulin pens come prefilled with insulin cartridge, while, the reusable insulin pens require an external cartridge which can be replaced once the cartridge runs out of insulin.

Some examples of these pens are disclosed in US5611783, US4592745, US4498904, US6004297 and US6663602. Various mechanisms for insulin pens have been described therein.

One problem withthe reusable pens, is that, there is a chance that cartridge may get contaminated or may not fit properly, which may lead to either inaccurate dose administration or administration of a contaminated dose which may lead to certain other threats.
With view of ameliorating this problem the current inventors propose a novel insulin pen which is a disposable insulin pen and can be used for accurate metered dosing of Human Insulin drug.

Summary of Invention:
The present invention discloses an insulin administration device which minimizes chances of contamination and wrong dosing due to human error during dosing with reusable pen device.

Brief Description of Drawings:
Fig. 1A illustrates the front view of insulin administration device (10) of the invention.

Fig. 1B illustrates the side of the insulin administration device (10) of the invention.

Fig. 2 depicts the internal placement of components of the insulin administration device (10), namely, hypodermic needle (211) and the insulin cartridge (212) in an administration mechanism (21) in syringe section (11).

Fig. 3 illustrates the exploded view of the insulin administration device (10) of the invention, in details.

Fig. 4 illustrates the exploded view of the dosingmechanism (22)of the insulin administration device (10) of the invention.

Detailed Description of Drawings:
Figs. 1A and 1B illustrate the external front view and external side view, respectively, of the multiple-use, disposableinsulin administration device (10) of the invention. The insulin administration device (10) comprises of a syringe section(11) and a body (12).The syringe section (11) comprises of a top cap (111) covering an administration mechanism (21) (shown in Fig. 2) and the body (12) comprises of a bottom barrel (121) covering a dosing mechanism (22) (shown in Fig. 2),an indicator window (122), cut out of the bottom barrel (121),which facilitates easy viewing of the set dose. The syringe section (11) and the body (12) are not detachable.

The drive tube (124) is moulded with copolymer acetyl resin having good mechanical strength. The setting dose numbers are printed on drive tube (124). The setting dose scale numbers are calibrated as per the maximum dosing capacity of device. The other parts such as a ratchet (221), a press knob (123), a sleeve (222) and a piston holder (223) are assembled in drivetube (124).

With reference to Figs. 2 and 3, the topcap (111) acts as a protective covering for administration mechanism (21) which comprises of a disposable needle (211) and a non-disposable insulin glass cartridge (212). The bottom barrel (121) covers dosing mechanism (22).

The disposable needle (211) is screwed or pressed on, using outer sheath as a thimble. The back end of the needle passes through a thin rubber stopper (214) at the tip of the administration mechanism (21), entering the chamber formed by cartridge holder (213), thereby piercing through the insulin cartridge (212) contained therein. The outer needle sheath (not shown) is then removed, followed by the inner sheath (not shown).

The disposable needle (211) could be any suitable syringe needle including the types having a common ISO standard screw thread attachment and those that can be pushed on the ISO thread fitting on the pen, provided the needle is less than 12.7 mm.

In an embodiment, the needle could be selected from, but not limited to, Micro-Fine 29G, Micro-Fine 30G or Micro-Fine 31G manufactured by BD Microfine (UK); PenFine 30G manufactured by Ypsomed (Switzerland); Model 29G or Model 30G manufactured by Shanghai HBM Healthcares, Inc. (China) andUnifinePentips 31G (4, 6, 8, 10, 12mm) needles manufactured by Owen Mumford, Inc. (UK).

The insulin cartridge (212), preferably, is a 3ml glass cartridge which could fit into cartridge holder (213) containing any pen administrable insulin product. The 3ml insulin cartridge (212) approximately contains about 300IUs of insulin.

In an embodiment, the dosing mechanism (22) comprises of the bottom barrel (121), the press knob (123), the drive tube (124), the ratchet (221), the sleeve (222), the piston holder (223), a cartridge holder cap (224), and a piston (225).

The bottom barrel (121) is provided with internal threads (not shown). Said internal threads are engaged with drive tube (124). The typical accuracy of threading of both parts is maintained to achieve correct insulin dose setting.

The dosing mechanism (22) further comprises of a ratchet (221). The ratchet (221) is moulded with copolymer acetyl resin having good mechanical strength. Ratchet (221) helps in creating clicking sound while setting dose. It also confirms the correct dose setting by audio for the patient having impaired vision.

The dosing mechanism (22) further comprises of the press knob (123). When pressure is applied on the press knob (123), the device injects the dose. After pressing the press knob (123), the drive tube (124) rotates and moves forward. The drive tube (124) in turn rotatesthe piston holder (223), engaged in drive tube (124) and creates audio signal by producing clicking sound to recognize proper dosing of insulin.

The sleeve (222) arrests rotation of the piston holder (223) and activates its linear motion. It also helps in creating clicking sound while setting dose. The sleeve (222) is assembled in drive tube (124) and engaged with piston holder(223). The piston holder (223) guides a piston (225).
The piston (225) is the most important part of Insulin Administration Device (10). The piston (225) is plastic injection moulded component of copolymer Acetyl Resin material having good mechanical strength. The dosing accuracy completely depends on the manufacturing accuracy of Piston (225). The piston threading (not shown) is designed to achieve accurate dosing of insulin. The piston (225) is assembled in drive tube (124) and engaged with piston holder (223) to achieve rotary and linear motion while injecting insulin. The piston (225) is also engaged with a cartridge holder cap (224) having internal trading of piston (225).

In an embodiment, the syringe comprises an axially movable or operable plunger which in turn drives the piston (225) of the syringe to express a dose of fluid. Accordingly, the glass insulin cartridge (212) is inserted in cartridge holder (213).The dosing knob (226) is placed on the glass cartridge (212). The cartridge holder cap (224) is fixed above glass cartridge (212) and gets locked in cartridge holder (213). The piston (225) is engaged in cartridge holder cap (224) and rests on dosing knob (226). The entire cartridge holder assembly is assembled with dosing mechanism (22). The top cap (111) is fixed and locked on the cartridge holder assembly.

The movable or operable plunger essentially comprises of the press knob (123) and the drive tube (124).The drive tube (124) is provided with indicia, for indicating the set dose.The indicia are deployed along a helical path on the drive tube (124) of the plunger. As the drive tube (124) moves helically, the markings pass successively under the window (122) cut in the bottom barrel (121) in the body (12).Simultaneously, as the drive tube moves helically, it pushes the piston (225) into the administration mechanism cavity (21).

There is a fiducially mark (1221) on the edge of the window (122) against which the marks are read. The marks correspond to setting increments of 1 (one) international unit (IU) of the insulin solution. The even numbered marks (and the mark for “1”) are labelled.The maximum rotation of the movable or operating plunger is three turns, which corresponds to 60 units (which will mean the delivery of 0.6 ml of solution). Thus when it reaches the end of its travel, the mark “60”will be in the window (122), aligned with the fiducially (1221).The drive tube (124) abutting the press knob (123) is used for setting the dose.

As the drive tube (124) is rotated longitudinally the piston (225) emerges from the bottom barrel (121) to a proportional distance.On full rotation, that is, when “60” appears in the window (122), the drive tube (123) has emerged approximately 1.25” from the housing compared to its “closed” position.

In an embodiment, the required insulin dose is set by rotating the drive tube (124) in clockwise direction. The required dose setting is shown at bottom barrel window (122). Open the top cap (111) from cartridge holder (213). The needle (211) is fixed at the end of the cartridge holder (213) covered by the top cap (111).

After setting the dose, the press knob (123) needs to be pressed to induce injection of insulin. After pressing the press knob (123), the drive tube (124) rotates in anticlockwise direction with respect to bottom barrel (121) along with the drive tube (124).The piston holder (223) rotates with respect to sleeve (222) and achieves linear movement of sleeve (222). The piston (225) engaged in the piston holder (223) and cartridge holder cap (224) also rotates along with piston holder. The piston (225) moves to linear direction renders the pressure to dosing knob (226) which injects the insulin through needle.

After delivery of total dose the drive tube (124) returns to its zero position. The Piston (225) stops at injecting position. When the piston (225) approaches the bottom of cartridge (212), the whole mechanism gets locked and cannot be reused for another insulin cartridge. The device shall need to be disposedoff after complete usage of insulin cartridge (213).

Detailed Description of Invention:
Described herein is a disposable insulin administration device which minimizes chances of contamination and wrong dosing due to human error.

In an embodiment, the insulin administration device (10) is an insulin pen.

In an embodiment, the insulin administration device (10) comprises of a unidirectional coupling. Said unidirectional coupling comprises of a ratchet and pawl mechanism. Accordingly, the press knob (123) coupled to the drive tube (124), the ratchet forming a unidirectional coupling which during the rotation of the button in one direction to set a dose rides or clicks over the teeth of the ratchet.

The cylindrical side of the drive tube (124) carries numbers which shows the amount of the set dose in a window when the button is screwed outward. When the press knob (123) is screwed back the unidirectional coupling will transmit the rotation to the piston holder (223) which has a nut (not shown) co-operating with a threaded piston rod (225) which is placed in the piston holder (223). This thread connection has a pitch which makes the nut self-locking on the piston rod.

In an embodiment, the drive tube (124) which is printed with dose number rotates in the bottom barrel (121). The bottom barrel (121) is the stationary part and the drive tube (124) moves up /down while rotating to clockwise or anticlockwise direction. The required dose setting shall be done by selecting the dose. The piston engaged in cartridge holder cap rotates along with dial barrel (124). The dose is administered by pressing the press knob (123). On delivery of dose the drive tube (124) rotates to home position, the piston (225) is pushed forward to dispense required dose and stops after complete administration of dose.

In an embodiment, the invention further provides a method for operation of the insulin administration device of the invention. To take a shot, the user first removes the top cap (111) from the syringe section (11) of the insulin administration device (10) of the invention. A new fully-sheathed disposable needle (211) is screwed (or for some types, pressed) on, using the outer sheath as a thimble. The back end of the needle passes through a thin rubber stopper (214) on the tip of the syringe section, entering the cartridge holder (213) holding the insulin cartridge (212). The outer needle sheath is then removed, followed by the inner sheath.The user then sets and arms the insulin administration device (10) for the desired dose by turning the drive tube (124) clockwise. As the drive tube (124) is turned, the piston (225) advances longitudinally, screwing itself out of the housing. As the drive tube (124) moves helically, the markings pass successively under the window (122) in the bottom barrel (121). There is a fiducially mark (1221) on the edge of the window (122) against which the marks are read. The marks correspond to setting increments of one international unit (IU) of the insulin solution. The even numbered marks (and the mark for “1”) are labelled.

While setting the required insulin dose, drive tube (124) rotates in clockwise direction from Zero position. The dose setting is done as per number shown in bottom barrel window (122).

The maximum rotation of the plunger is three turns, which corresponds to 60 units (which will mean the delivery of 0.6 ml of solution). Thus when it reaches the end of its travel, the mark “60”will be in the window, aligned with the fiducially. At this point, the piston (225) has emerged approximately 1.25” from the housing as compared to its “closed” position.

The user then inserts the needle at the injection site. Holding the pen body with the fingers of one hand, the thumb of that hand (typically) is used to press the press knob (123) on the setting knob in order to drive the operating plunger back into the pen body.

In an embodiment, the insulin administration device can be used with replaceable needles, including the types having a common ISO standard screw thread attachment and those that can be “pushed on” the ISO thread fitting on the pen.

The dose is induced by pressing the press knob (123) which helps in rotating of drive tube (124) in anticlockwise direction and axial movement of the piston (225) to inject the required dose through syringe. The drive tube (124) returns to its Zero position after complete injection of set dose.

The initial pressure on the press knob (123) shifts the mechanism from the armed mode to the delivery mode. As the operating plunger spirals back into the pen housing, the mechanism moves the piston (225) by a much shorter, accurately scaled distance. This delivers the dose through the needle when the operating plunger returns to zero position (showing “0”on the scale), the dose delivery is complete. Accordingly, the rotational movement of the drive tube (124) is induced by the axial movement of the injection button so that the scale is returned to its zero position.

The user withdraws the needle from the injection site, replaces the outer sheath on the needle, and using it as a thimble, unscrews the needle from the pen and discards it. The cap is replaced on the pen. With the cap off, the syringe piston (225) is visible through the transparent cartridge holder (213), which is provided with a scale showing approximately the amount of insulin solution still available for delivery. The mechanism keeps precise track of the amount of insulin solution remaining available for delivery, and does not allow the user to set a dose greater than that. If there is no insulin solution available for delivery, the drive tube (124) cannot be turned at all.

In an embodiment, the device is dispensed pre-filled with 3 ml cartridge of insulin solution or suspension, corresponding to 300 international units (IU) of insulin, which may be used for numerous “shots”. For each shot, the user attaches the disposable needle (211) and sets the desired dose by rotating the drive tube (124). Then, after insertion of the disposable needle (211) at the tip of injection site, the user presses the press knob (123), leading to accurate deliveryof the pre-set dose.Once the pre-filled cartridge delivers its entire contents the device is discarded. It cannot be refilled in the field.

In an advantageous embodiment, the device (10) of the invention improves patient compliance and is more economical.

In an advantageous embodiment, the insulin administration device (10) delivers accurate dose of the insulin.

In an advantageous embodiment, the insulin administration device (10) of the invention facilitates easy and accurate administration of metered dose.

In another advantageous embodiment, the insulin administration device (10) minimises chances of the contamination and wrong dosing dueto human error during dosing with reusable pen device.

It may be noted that, eventhough, the present invention has been discussed with reference to administration of insulin, the same device may be used for administration of other injectable peptide as well.