FORM - 2
THE PATENTS ACT, 1970
PROVISIONAL
Specification
SECTION -10


DRY POWDER INHALER
SUN PHARMACEUTICAL INDUSTRIES LTD.
of Acme Plaza, Andheri-Kurla Road, Andheri (E),
Mumbai 400 058, Maharashtra, India, an Indian Company

THE FOLLOWING SPECIFICATION DESCRIBES THE NATURE OF THIS INVENTION:-


The present invention relates to a dry powder inhaler.
BACKGROUND OF THE INVENTION
Dry powder inhales are known and successfully marketed. Some of the marketed single dose dry powder inhalers include Spin haler, Rotahaler and others whereas some of the multidose dry powder inhalers include Turbuhaler and Diskhaler among the many others.
The present invention relates to a dry powder inhaler for delivery of a medicament in solid, finely divided form to a patient by oral inhalation. The dry powder inhaler of the present invention also provides for multiple dosing.
United States Patent Nos. 4811731 and 5035237 (Glaxo Group Ltd.) [no Indian equivalent] relate to a dry powder inhaler for administering medicaments in solid finely divided form to patients wherein the dry powder inhaler consists of a housing, a carrier mounted in the housing which is movable relative to the housing, a rotatable support disk provided on the carrier and adapted to receive a carrier or blister pack provided with the medicament. A plunger is operable to penetrate a container in the blister pack registered therewith to open the container to a pathway leading to an inhalation mouthpiece. The movement of the carrier from its first to its second position causes the support to bring a blister container into registration with the plunger. When the lid is raised,

the plunger pieces the blister. In the dry powder inhaler disclosed in the said US patents , the rotatable support base and the blister pack are in a locked and fixed position and there are no indication means such as arrow marks on the blister pack and the mouthpiece to ensure complete registration with the dosing chamber for maximizing the total percent of dose emitted from the dry powder inhaler upon inhalation by the patient. Also there is a significant degree of play between the blister pack and the support disk resulting in the off center puncturing of the blister pack.
One amongst other objectives of this invention is to provide a dry powder inhaler with improved delivery of medicaments contained in the blister pack.
It has been found that by proper alignment and also by preventing movement of the blister pack in relation to the support disk such that the blister pack is ruptured in the center, an improvement in the percent of dose emitted from the inhaler can be achieved.
According to the present invention there is provided a dry powder inhaler for administering medicaments in solid finely divided form to patients, comprising a housing; a carrier mounted in the housing; a rotatable support disk provided on the carrier and adapted to receive, in use, a blister pack; and a plunger, to penetrate a blister container registered therewith.

The invention will now be described with reference to the accompanying drawings, in which
Figure 1 is the outer casing of the dry powder inhaler in accordance with
this invention;
Figure 2 is the assembly drawing sectional view of the inhaler of figure
1;
Figure 3 is the end sectional view of the inhaler of figure 1;
Figure 4 is the plan view of the wheel for the carrier for the dry powder
inhaler of figure 1;
Figure 5is the side elevation of the wheel of figure 4;
Figure 6 is the enlarged view of the engraving seen as part 46 in figure 4;
Figure 7 is the detailed view of the part 32 seen in figure 5;
Figure 8 is the plan view of the mouth piece and its position with respect
to the carrier wheel for the inhaler of figure 1;
Figure 8a shows the enlarged detail of part 47 and 48 in figure 8,
Figure 8b is the enlarged view of part 48 in figure 8a,
Figure 9 is a detailed view of the mouth piece and tray of the inhaler of
of figure 1; and
Figure 10 is a detailed view of the body of the inhaler of figure 1 with
enlarged view of certain portions marked in the figure 9.
The drawings of the embodiment and the description relating there to are provided for illustrative purposes only and do not in any way limit the nature and the scope of this invention.

Referring to the drawings, a preferred embodiment of the dry powder inhaler In accordance with the present invention is shown in the accompanying drawings which consists of four principal elements, namely a housing 1, a wheel carrier 2, a rotatable support 3 and a cover 4. The support 3 is designed to receive a blister pack [not shown].
The housing 1 consists of a base element 10 and a lid 11 hinged thereto by pivots 12. The base element 10 has a base wall 13 , upstanding side and rear walls 14 and 15 and a top wall 16 which spans the forward portion of the base element to form a kind of bridge. The top wall has an aperture 17 which also acts as an air inlet into the dry powder inhaler. A plunger is formed or provided which typically may be curved to pierce the exact centre of the blister container.
The carrier 2 as particularly seen in figures 4 to 6 defines a shallow chamber 20 for receiving the rotatable support 3. In the center of the chamber 20 is an upright lug 21 see figure 9 on which the support 3 is mounted for rotation. The carrier 2 can be moved in the housing between an inward position and an outward position. Further outward movement beyond a predetermined outward position is normally prevented by a lug 23 which is formed on the end of an arm 22 and which engages behind an inwardly directed protrusion on one of the side walls 14 of the housing 1. The arm 22 is secured to the rest of the carrier only at its forward end and is substantially separated from the rest of the carrier by a slot 24. The arm 22 is resilient, and when it is desired to remove the carrier completely from the housing this can be achieved by pressing the arm 22 inwardly

and then withdrawing the carrier. Withdrawal is assisted by the provision of a thumb grip 33, in the form of ribs, on both sides of the carrier. The carrier also has a tongue 25 which can depressed downwardly, and which has an open slot 26. Extending from the front of the carrier 2 is a mouthpiece 27. It is through this mouthpiece that medicament leaves the dry powder inhaler in the course of inhaling by a patient.
A rotatable disc 3 is provided in which is formed a circle of openings 30, typically circular. These openings receive the bhster containers of the blister pack. A central opening 31 enables the carrier to be mounted rotationally on the lug 21. Four elevations or projections 32 are present on thee upper side of the support 3. A bhster pack[not shown] is provided with four holes or depression such that the elevations or projections of the support associate with corresponding holes or depressions in the circular blister pack. The bhster pack is mounted on the rotatable support such that the elevations or projections of the support are interlocked in the corresponding holes or depressions of the bhster pack. This arrangement restricts any possible movement of the blister pack. There is also an indication means such as an arrow on the mouthpiece 45 and on the carrier 46 which align with and arrow on the circular blister pack 46 [not shown]. The arrows 45 and 46 permit the patient to ensure that the support disk with the bhster pack in a locked position are placed such that the arrows 45 and 46 coincide with the arrow on the blister pack. This ensures that the ruptured opening in the blister pack is always in the center of the blister pack 5 which also carries a series of numbers, arranged in a circle, corresponding to the number of blisters in the pack. The top wall 16 of the

housing 1 has a aperture 34 through which a respective one of the numbers is visible to indicate the number of the blister then aligned with the aperture 17, and hence to indicate how many blisters are left for use, or alternatively how many blisters have been used.
In use, the cover 4 is removed and the carrier with the support 3 mounted thereon, is then removed completely from the housing 1 after 22 has been depressed. A blister pack 5 is then mounted on the support 3 with one blister container extending into each of the openings 30. The carrier, support and blister pack are then inserted together into housing. The cover 4 is then replaced. When a patient desires to inhale medicament he removes the cover and raised the lid 11 so as to cause the plunger 18 to pass through the aperture 17 and puncture a respective blister located immediately below the aperture 17. the lid is then lowered to withdraw the plunger from the bhster, leaving a hole therein, and the patient inhales the medicament through the mouthpiece 27. Either before replacing the cover, or on the next occasion when the patient desires to use the dry powder inhaler, the support 3 is rotated to bring the next blister beneath the aperture 17. This is achieved by the movement of the carrier. The carrier 2 is withdrawn to its outward position and then pushed back to its inward position. During the latter movement an arm which extends forwardly in the casing land is secured to the base wall 13 thereof engages one of the ribs on the underside of the support 3. This causes the support to rotate in a clockwise direction by an amount sufficient to bring the next blister container beneath the aperture 17. During this rotational movement another of the ribs bears against, and progressively depresses, the tongue 25 until that rib engages in the slot 26 which retains the support in its desired position and prevents further rotation.

Several factors that are considered in preparation of preferred embodiments of the dry powder inhaler. Generally the size of the dry powder inhaler is a factor that determines the size of the bhster pack, the number, size and design of cavities in the support disk and the bhster pack used in thee inhaler and consequently the design of the air flow path for the particles. Thus the inhaler may be suitably designed so that it may be used for different products having a range of doses. The size of the inhaler also determines the ease of handling of the inhaler by the patient. The amount or percentage of the drug emitted from the inhalation devices and thus also the percentage reaching these sites, which may be located in the peripheral airways, is one of the major factors for the design of a successful dry powder formulation. The two-stage liquid impinger is used specifically to assess the delivery of drugs from the inhalers. This apparatus is official in the British Pharmacopoeia and its use for determining fine particle dose and fine particle size distribution of aerosol of inhalers is well known in the art. The inhaler of the present invention was compared with the marketed preparation using this apparatus.
Comparative data of fine particle fraction studies between salbutamol sulphate inhaler of the present invention and marketed preparation (Ventolin Diskhaler) is given below in Table 1.
TABLE 1 Flow Rate : 60 L / mm

Dry powder inhaler TED* as % ofLC**
Inhaler of the invention 65.71
Marketed inhaler [ventolin] 56.74

* TED is the total emitted dose. It signifies the amount of drag available from the dry powder inhaler to the patient after inhalation. ** LC is he label claim. This is the amount of drug present in each blister container of the blister pack.
It was observed that the total emitted dose was higher for the improved inhaler of the present invention.
Several modifications of the invention can be envisaged without departing from the nature and the scope of the invention as described in the description herein above. For instance the elements can be made of inert metal or reinforced plastics and synthetic polymeric material. The present invention now aims at increasing the stability of a dry powder inhaler of the kind mentioned and includes an adjusting and fine tuning which permits optimum availability of the dry powder to the patient.
Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.

Dated this 9th day of October 2002
Mohan Dewan OfRKDewan&Co Applicant's Patent Attorneys