GB2263068A

GB2263068A - Inhalation device

Info

Publication number: GB2263068A
Application number: GB9205089A
Authority: GB
Inventors: David Keith Smith
Original assignee: Minnesota Mining and Manufacturing Co
Current assignee: 3M Co
Priority date: 1991-12-19
Filing date: 1992-03-09
Publication date: 1993-07-14
Anticipated expiration: 2012-03-09
Also published as: GB2263068B; GB9205089D0

Description

1.

is 2263068 INHAnATION DEVICE This invention relates to inhalation devices for the administration of aerosolised medicament to the respiratory system of a patient and in particular to an inhalation device incorporating security means to discourage unauthorised tampering and/or use of the device.

Since the metered dose pressurised inhaler was introduced in the mid 1950s, inhalation has become the most widely used route for delivering bronchodilator drugs and steroids to the airways of asthmatic patients. Compared with oral administration of bronchodilators, inhalation offers a rapid onset of action and a low instance of systemic side effects. More recently, inhalation from a pressurised inhaler has been a route selected for the administration of other drugs, such as, ergotamine, which are not primarily concerned with treatment of a bronchial malady.

The two most widely used and convenient choices of treatment have been the inhalation of medicament from a drug solution or suspension in a metered dose pressurised inhaler or inhalation of a powdered drug, generally admixed with excipient, from a dry powder inhaler. Examples of such inhalation devices aredisclosed in British Patent Nos. 118341, 1268051, 1 p 2 1269554, 1335378, 1392192, 1526303, 2041763, 2061116, 2061735, 2165159 and 2191718; U.S. Patent Nos 2587215, 3187748, 3456644, 3456645, 3456646, 3598294, 3605738, 3636949, 3669113, 3732864, 3789843, 3814297, 3971377, 4046146,4098723, 4137914, 4147166, 4192309, 4240418, 4674491 and 4846168; European Patent No. 237507; International Patent Publication No. WO 90/073351 and German patent No. 3040641.

A problem common to many of these devices, particularly if controlled substances or highly potent or expensive drugs are to be.dispensed, is the potential for the patient to misuse the device by exceeding the prescribed dose regimen. This problem would be particularly acute when dealing with controlled drug substances, such as narcotic analgesics which are often prescribed for patients in severe pain, e.g., the terminally ill, or for persons with a drug habit. In such cases, the desire to relieve the pain or to satisfy their addiction may be so great that the patient could, on exceeding the prescribed dose frequency, overdose with potentially very serious consequences.

Although some devices currently used -for delivery of controlled drugs-incorporate means to control the number of doses of medicament dispensed overa given time interval, unless the patient is continuously monitored by the nursing staff, there is- still a risk that..he or she - cl p 3 will attempt to bypass any control facilities by removing the medicament container from the device and inserting it in another device where the dosage regimen is not so strictly controlled.

Therefore the present invention seeks to provide inhalation devices having security means to discourage unauthorised tampering and/or use thereof.

According to the present invention there is provided an inhalation device for the ad-ministration of aerosolised tedicament to the respiratory system of a patient, the device comprising a reusable housing accommodating a replaceable reservoir of medicament and a patient port adapted for insertion into the mouth or nasal passage of the patient, the device being arranged such that patient inhalation at the patient port generates an airstream through the device which entrains medicament from the reservoir for inhalation by the patient, and in which the device comprises one or more security means selected from:

(1) means to disable or otherwise render the device unusable upon unauthorised removal and subsequent replacement of the medicament reservoir; (2) means to disable or otherwise render the medicament reservoir unusable upon its unauthorised removal, and (3) means to indicate th at the reservoir has been so removed and replaced.

The inhalation devices of the invention are I. p 4 preferably of the reusable type in which the medicament reservoir can be replenished once exhausted and/or used with different types of medicament, although any format of device where, in the interests of patient safety, the device must be capable of being controlled or otherwise adjusted depending on the type of medicament to be administered, can be used.

The device may be of the dry powder type, pressurised aerosol type or contain other aerosol generators, e.g., atomizers. Thus, the medicament reservoir may take a wide variety of formats including a conventional pressurised aerosol canister equipped with a metering valve or a container holding dry powder or a solution or suspension of medicament. The container may be incorporated into a refill cartridge which is mounted on or inserted into the body of the device. The container may be arranged so as to be replenishable with additional medicament once exhausted or, alternatively, the exhausted container (or cartridge) may simply be discarded and replaced.

In one embodiment of the invention, the medicament reservoir may be in the form of a cartridge containing an elongate carrier bearing powdered medicament as disclosed in our copending International Patent Application No. PCT/US90/02412.

The inhalation devices of the invention are arranged such that the removal or separation-by an unauthorised person of-the medicamentreservoir from the c c main body of the device renders one or both units inoperable. "Unauthorised" as used herein generally refers to anyone other than a physician, pharmacist or nurse and would ordinarily include the patient. For example, if the device is breath-actuated, the removal/separation of the medicament reservoir may disable the breath-actuation mechanism. Alternatively, the two units may be arranged such that they cannot be rejoined once separated or, the reservoir may be locked to the body of the device such that only an authorised person in possession of the appropriate 'key' can separate the two units.

The nature of the disabling feature may be either permanent or temporary.

The device may also include means to indicate to an authorised person the fact that the two units have been separated and rejoined. The indicator means may be visual, e.g., a lamp, LED, LCD or security tab, and/or aural, e.g., a tone generator.

In a preferred embodiment of the invention, the device comprises an inhalation device of the type disclosed in our copending British Patent Application No. 9126988.6 filed 19th December 1991 in which the device reads information from the medicament reservoir and uses that in2ormation to control the dispensing of,the medicament.

The means of detecting the information on the reservoir of medicament may take a variety of forms, 6 including:

1. Coded electrical contacts, in the form of wipers, spring loaded contacts or pins/sockets on the medicament container (or its holder) which mate with appropriate equivalent contacts on the body of the inhalation device. Such an arrangement is comparable to DX-coding in cameras which is disclosed, for example, in U.S. Patents Nos, 4,655,568 and 4,799,075.

2. Coded reflective strips on the medicament container (or its holder) which reflect light from phototransmitters on the body of the inhalation device to photodetectors thereon. Such strips would be comparable to barcoding.

3. A magnetic strip on the medicament container (or its holder) which holds recorded information which can be read by a magnetic reader when the container is inserted into the inhalation device.

4. A coded pattern of pieces of magnetic material on the medicament container (or its holder) which interact with a series of reed switches on the body of the inhalation device.

5. A coded series of projections on the medicament container (or its holder) which interact with a series of switches on the body of the inhalation dev--.ce. These switches may be of any suitable form, for example, they may be of push-button rocker paddle or slide type or of any combination of types. They may be of the momentary action type (each. reverting to its own 4.0 7 known default state when the reservoir is removed), or they may be of a sustained action type, for example, rocker switches set to the required positions by insertion of each reservoir, but not its subsequent removal. In the case of the sustained action type of switches, it may be preferable that the coded projections are on the holder and that said container and holder are permanently joined i.e. cannot be separated without rendering the container unusable, and that the device body is so configured that a drug container cannot properly be inserted without a holder. Thus an uncoded medicament container (for example, a standard pressurised aerosol container) could not be used in an inhaler body already programmed by the previous reservoir. such permanent joining of the holder to the medicament container would prevent the insertion of the latter into some other uncontrolled inhaler or adaptor in order to bypass any control facilities (e.g. dosage frequency control).

The information detected by the sensing means normally relates to the contents of the medicament container and may include one or more of the following 1. Label claim number of doses in container; 2. Type of drug, e.g., bronchodilator, steroid anti-allergic; 3. Strength of formulation; 4. Maximum number of doses permitted at one time; 5. Maximum dosage frequency; t.0 8 6. Recommended dosage regimen, and 7. Manufacturer's expiry date.

The inhalation device may be programmed to display the information sensed, e.g., on a liquid crystal display, and/or to use the information to control the manner in which the medicament is dispensed.

Claims

The inhalation device may also incorporate means to transfer information to the medicament reservoir. For example, the 'medicament container may be provided with a magnetic strip and the body of the inhaler with a magnetic head which records information onto or erases it from the strip. This information may include, for example, the number of doses dispensed from and/or the number of doses remaining in the container up to the Label Claim number of doses. Alternatively, the medicament container may be provided with a non-volatile memory chip. In this manner, the partially full medicament container from a device used by a patient who has completed his or her course of treatment may be retained for reuse at a later date, but only if the number of doses remaining in the container before the Label Claim number of doses is reached can be recorded. Suchre-use may involve the programming of an inhalation device of the present invention with a code by some authorised person. This invention will now be described by way of example with reference to the accompanying drawings, in which: C..41 is 9 Figure 1 illustrates an inhalation device in accordance with the invention; Figure 2a illustrates the body unit of the device of Figure 1; Figure 2b illustrates the demountable reservoir of the device of Figure 1; Figure 3a is an end view of the reservoir, and Figure 3b is an end view of the body unit. The drawings illustrate a reusable, portable, pocket-sized inhalation device of the type disclosed in our copending British Patent Application No. 9126988.6 filed 19th December 1991 for administering doses of medicament from a conventional pressurised aerosol canister equipped with a metering value. Referring specifically to Figure 1, the device (2) comprises a body unit (4) containing electronic sensing means, an electronic control circuit and a breathactuation mechanism, and a demountable medicament reservoir (6) which includes an adaptor (8) for the aerosol canister and a patient port in the form of a mouthpiece (10). In the embodiment shown, the mouthpiece (10) is separable from the adaptor (8). The body unit (4) also contains electromechanical means for priming/actuating the device (2) to dispense medicament in response to patient inhalation at the mouthpiece (10), e.g., as disclosed in our copending International Patent Application No. PCT/GB91/01116 filed Sth July 1991.The 1 1 1 jr, - r electronics of the device (2) are powered by a battery (not shown) mounted within the body unit (4). Referring to Figures 2 and 3, the reservoir (6) is coupled to the body unit (4) by means of interengaging connector portions (12 and 14). In the embodiment shown, coded electrical contacts (20) on the reservoir (6), which may take the form of wipers, spring-loaded contacts or pins/sockets, mate with the appropriate contacts (22) on the body unit (4) to allow it to read the information necessary to control the dispensing of the medicament and/or the display of that information via liquid crystal display (LCD) (24). Such information may include, for example, the nominal (Label Claim) number of doses contained in the aerosol canister, the type and strength of the medicament, the maximum number of doses permitted at any one time, the dosage frequency, the recommended dosage regimen, 'use beforel date and so on. The contacts (20) on the reservoir (6) may also take the form of a bar code which reflects light from a phototransmitter on the body unit(4) to a photodetector thereon or, alternatively, a magnetic strip which can be read by a magnetic reader. The reservoir contacts may also be provided on the aerosol canister rather than the reservoir. In either case, the provision of such contacts makes it impossible to use a reservoir/aerosol canister which does not have the appropriate contacts for a given bodyunit. Moreover, they facilitate.means to render a partially used reservoir unusable on its A; 11 separation from the body unit or, where the contacts are provided on the aerosol canister, by removal of the canister from the adaptor, e.g., by erasing or defacing the magnetic/bar code. The body unit (4) is provided with a plurality of air inlets (28) and a breath sensor port (30) which communicates with air inlets (32) provided in the housing of the reservoir (6). The patient operates the device (2) by pressing an ONIOFF button (not shown) on the body unit (4), thereby powering up and optionally priming the device (2) for use, and inhaling through the mouthpiece (10). The primed status of the device may beIndicated via a lamp, e.g., an LED (not shown) or the LCD (24). When the patient inhales through the mouthpiece (10) of the device (2), an airflow is quickly established through the body unit (4), the breath sensor port (30) and the reservoir (6) via the air inlets (28 and 32). A breath sensor (not shown) detects the developing airstream, whereupon electronic control means actuates the valve actuation plunger (34) to depress the body (36) of the aerosol canister (38) relative to the stem (40) of the metering valve (not shown). A dose of medicament is released through the support block assembly (42) into the mouthpiece (10) where it is entrained by the patient's inspiratory efforts into his or her lungs. The inhalation device (2) is ordinarily prescribed for use by a patient by his or her physician, with the pharmacy staff selecting the appropriate aerosol canister a ' &I is 12 according to the physician's instructions. To assemble the device (2), the pharmacist inserts the relevant aerosol canister (38) into the adaptor (8), attaches the mouthpiece (10) and then couples the completed reservoir (6) to the body unit (4). The contacts (20 and 22) mate on coupling to enable the electronic control circuit to detect at least (i) the number of doses contained in the canister (38) and optionally (ii) the maximum number of doses permitted at any one time and (iii) the maximum dose frequency. Some or all of this information may then be displayed by the LCD (24). When the patient inhales a dose of medicament from the device (2), the displayed contents indication numeral is reduced by one. The patient may then be allowed a short period of time in which to take a further dose or doses up to the Label Claim number of doses permitted at any one time. When the maximum number of doses has been dispensed, the device (2) may deactivate such that the number of available doses can be precisely controlled, as well as preventing the dose size tailing off. When the aerosol canister (38) has dispensed the maximum number of doses of medicament or the course of treatment is finished, then the device (2) is returned to the pharmacy for sterilisation prior to its reuse. The device (2) may comrrise means for completely sealing the body unit (4) to allow for its immersion in a disinfectant solution. The sealing means may take the form of sliding seals (not shown).over the air inlets 0 ' a 13 (28) and the breath sensor port (30) and a flexible membrane (35) around the valve-actuation plunger (34) to prote ct the electronics of the body unit (4) against the ingress of the disinfectant solution. In the embodiment shown, the reservoir (6) is uncoupled from the body unit (4) and the mouthpiece (10) separated from the adaptor (8) and hygienically disposed of by the pharmacy staff. The aerosol canister (38) is then removed from the adaptor (8) and safely disposed of. Once the adaptor (8) and body unit (4) have been sterilised, they can be returned to the pharmacy to await their reuse at a later date. The inhalation device (2) is provided with means to prevent an unauthorised person, including the patient, from tampering with the device (2) and bypassing any control facilities, e.g., the dosage control frequency, by removing the aerosol canister (38) and inserting it in some other device where the dosage regimen is not so controlled. For example, the connector portions (14 and 12) of the reservoir and body unit (6 and 4) may be capable of being locked together such that only an authorised person in possession of the appropriate key or code can uncouple them. Such a locking mechanism may take a wide variety of formats including by ways of example, a simple combination lock which may be operated electronically or mechanically by input of a code. While an unauthorised person can force the body unit and reservoir (4 and 6) apart, the device (2) is 1.

1 0 is 14 preferably constructed such that either one or both units are disabled thereby, for example, by preventing their rejoining after forcible separation. The connector portion (14) of the reservoir (6) may comprise one or more frangible tabs which break on forced separation to prevent it from being reattached to the body unit (4). The LCD (24) may also register the fact that the two units (4 and 8) have been so separated to provide a visual indication to the pharmacy staff that the device has been tampered with, for example, a switch or pushbutton (26) may be provided on the body unit (4) which is released on separation and depressed on recoupling of the reservoir (6) and which signals the control unit to illuminate a lamp (not shown) or the LCD (24).

The mouthpiece (10) and adaptor (8) may also comprise a frangible connection therebetween, such that removal of the mouthpiece (10) prevents its later reattachment.

The reservoir (6) may be provided with means to secure the aerosol canister (38) into the adaptor (8) such that it cannot be readily removed from the unit without damaging the adaptor (8) and/or the canister (38). For example, in the embodiment shown, the inner walls of the adaptor (8) are provided with a plurality of lugs (44) which engage the periphery of the ferrule (46) of the canister (38) to prevent its withdrawal therefrom. Preferably, the forcible removal-of.the aerosol canister 0 f t is is (38) from the adaptor (8) has the effect of rendering the valve mechanism inoperable. For example, the support block assembly (42) may include means to lock the stem (40) of the valve into the socket (48) of the support block (50).

The advantages of a device having means for enhancing the security of its contents in accordance with the invention are as follows:

a) Locking together the medicament reservoir and the body unit of the inhalation device-will minimise the risk of either component being tampered with.

b) Provision of means for permanently retaining the aerosol canister in the adaptor of the reservoir will make it substantially more difficult for an unauthorised user to transfer the aerosol canister to another, uncontrolled inhalation device/adaptor. In conjunction with the facility for removal and disposal of the mouthpiece this will enable a part used reservoir to be effectively rendered unusable.

Additionally:

provision of the facility for sealing the body unit will facilitate disinfection of its outer surfaces after use.

provision bf a removable mouthpiece will facilitate hygienic disposal of this component.

I- 1 16 CLAIMS:

An inhalation device for the administration of aerosolised medicament to the respiratory system of a patient, the device comprising a reusable housing accommodating a replaceable reservoir of medicament and a patient port, the device being arranged such that patient inhalation at the patient port generates an airstream through the device which entrains medicament from the reservoir for inhalation by the patient, characterised in that-the device further comprises one or more security means selected from:

(1) means to disable or otherwise render the device unusable upon unauthorised removal and subsequent replacement of the medicament reservoir; (2) means to disable or otherwise render the medicament reservoir unusable upon its unauthorised removal, and (3) means to indicate that the medicament reservoir has been so removed and replaced.

2. An inhalation device as claimed in claim 1 in.

which the reservoir comprises a pressurised aerosol canister equipped with a dispensing valve comprising a valve stem movable between a closed and a dispensing position.

3. An inhalation device as claimed in Claim 2 in which the medicament reservoir further comprises a housing supporting the aerosol canister and a support.

block having a socket adapted to-receive the stem of. the W 17 dispensing valve and a through-orifice communicating with the socket and patient port, the aerosol canister and support block being reciprocally movable relative to each other to cause the stem to move to its discharge position.

4. An inhalation device as claimed in any preceding Claim further comprising means to secure the"medicament reservoir to the device such that it can only be removed by an authorised person.

5. An inhalation device as claimed in any preceding Claim in which the removal of the medicament reservoir involves the breaking of a frangible joint which prevents its subsequent refitting.

6. An inhalation device as claimed in any preceding Claim further comprising means to secure the aerosol canister into the medicament reservoir to prevent its removal therefrom.

7. An inhalation device as claimed in Claim 6 in which the medicament reservoir is provided with one or more projecting lugs which engage and secure the aerosol canister in position in the medicament reservoir.

8. An inhalation device as claimed in Claim 6 in which the support block of the medicament reservoir includes means to secure the stem of the dispensing valve in position.

9 A device as claimed in any preceding Claim further comprising means for controlling the dose regimen.

0 '1 5 18 10. An inhalation device as claimed in any preceding Claim in which the medicament reservoir comprises information relating to the medicament contained therein and the device includes sensing means capable of detecting the information and means to display and/or use the information so detected. 11. An inhalation device as claimed in Claim 10 in which said information is encoded on the housing of the medicament reservoir. 12. An inhalation device as claimed in claim 10 in which said information is encoded on the aerosol canister. 13. An inhalation device as claimed in any one of Claims 10 to 12 in which the sensing means comprises electrical contacts on the device which mate with coded electrical contacts in the form of wipers, spring-loaded contacts or pins/sockets on the medicament reservoir. 14. An inhalation device as claimed in any one of Claims 10 to 12 in which the sensing means comprisps photodetectors which detect light emanating from phatotransmitters on the device and reflected from coded reflective strips on the medicament reservoir. 15. An inhalation device as claimed in any one of Claims 10 to 12 in which the sensing means comprises a magnetic reader which reads information stored on a strip of magnetic recording material on the medicament reservoir.

v 19 16. An inhalation device as claimed in any one of Claims 10 to 15 in which said information comprises one or more of the following:

(a) number of dose contained in the medicament reservoir; (b) type of medicament in reservoir; (c) strength of formulation; (d) maximum number of doses permitted at one time; (e) maximum dosage frequency; (f) lock-out interval after dosing; (g) recommended dosage regimen, and (h) 'use before'/expiry date. 17. An.inhalation device as claimed in any one of Claims 10 to 16 in which at least a portion of the information is destroyed or erased by removal of the medicament reservoir or aerosol canister. 18. An inhalation device as claimed in any preceding Claim further comprising means to detect patient inspiration at the patient port and means to dispense medicament in response to said inspiration. 19. An inhalation device as claimed in Claim 18 in which the separation of the medicament reservoir and/or removal of the aerosol canister therefrom disables the breath-actuation mechanism. 20. An inhalation device as claimed in any preceding Claim in which the patient port is demountable from the device.

q.. fa f 21. An inhalation device as claimed in claim 19 in which the removal of the patient port involves the breaking of a frangible joint which prevents its subsequent refitting. 22. An inhalation device as claimed in any preceding Claim in which the medicament is a controlled substance. 23. An inhalation device as claimed in Claim 1 substantially as herein described with reference to the accompanying drawings.

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