WO2016180975A1 - Kit for performing a bronchial challenge test with methacholine and device containing methacholine - Google Patents

Kit for performing a bronchial challenge test with methacholine and device containing methacholine Download PDF

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Publication number
WO2016180975A1
WO2016180975A1 PCT/EP2016/060901 EP2016060901W WO2016180975A1 WO 2016180975 A1 WO2016180975 A1 WO 2016180975A1 EP 2016060901 W EP2016060901 W EP 2016060901W WO 2016180975 A1 WO2016180975 A1 WO 2016180975A1
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WIPO (PCT)
Prior art keywords
fluid
chamber
methacholine
piston
atomizing
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PCT/EP2016/060901
Other languages
French (fr)
Inventor
Pietro Longo
Original Assignee
Medical Graphics Italia S.R.L.
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Publication of WO2016180975A1 publication Critical patent/WO2016180975A1/en

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    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M11/00Sprayers or atomisers specially adapted for therapeutic purposes
    • A61M11/001Particle size control
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M15/00Inhalators
    • A61M15/0065Inhalators with dosage or measuring devices
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05BSPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B1/00Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means
    • B05B1/26Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means with means for mechanically breaking-up or deflecting the jet after discharge, e.g. with fixed deflectors; Breaking-up the discharged liquid or other fluent material by impinging jets
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05BSPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B11/00Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use
    • B05B11/01Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use characterised by the means producing the flow
    • B05B11/10Pump arrangements for transferring the contents from the container to a pump chamber by a sucking effect and forcing the contents out through the dispensing nozzle
    • B05B11/1001Piston pumps
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05BSPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B11/00Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use
    • B05B11/01Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use characterised by the means producing the flow
    • B05B11/10Pump arrangements for transferring the contents from the container to a pump chamber by a sucking effect and forcing the contents out through the dispensing nozzle
    • B05B11/1042Components or details
    • B05B11/1073Springs
    • B05B11/1074Springs located outside pump chambers
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05BSPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B11/00Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use
    • B05B11/01Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use characterised by the means producing the flow
    • B05B11/10Pump arrangements for transferring the contents from the container to a pump chamber by a sucking effect and forcing the contents out through the dispensing nozzle
    • B05B11/109Pump arrangements for transferring the contents from the container to a pump chamber by a sucking effect and forcing the contents out through the dispensing nozzle the dispensing stroke being affected by the stored energy of a spring
    • B05B11/1091Pump arrangements for transferring the contents from the container to a pump chamber by a sucking effect and forcing the contents out through the dispensing nozzle the dispensing stroke being affected by the stored energy of a spring being first hold in a loaded state by locking means or the like, then released
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01FMEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F11/00Apparatus requiring external operation adapted at each repeated and identical operation to measure and separate a predetermined volume of fluid or fluent solid material from a supply or container, without regard to weight, and to deliver it
    • G01F11/02Apparatus requiring external operation adapted at each repeated and identical operation to measure and separate a predetermined volume of fluid or fluent solid material from a supply or container, without regard to weight, and to deliver it with measuring chambers which expand or contract during measurement
    • G01F11/021Apparatus requiring external operation adapted at each repeated and identical operation to measure and separate a predetermined volume of fluid or fluent solid material from a supply or container, without regard to weight, and to deliver it with measuring chambers which expand or contract during measurement of the piston type
    • G01F11/025Apparatus requiring external operation adapted at each repeated and identical operation to measure and separate a predetermined volume of fluid or fluent solid material from a supply or container, without regard to weight, and to deliver it with measuring chambers which expand or contract during measurement of the piston type with manually operated pistons
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M2209/00Ancillary equipment
    • A61M2209/06Packaging for specific medical equipment
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05BSPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B1/00Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means
    • B05B1/26Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means with means for mechanically breaking-up or deflecting the jet after discharge, e.g. with fixed deflectors; Breaking-up the discharged liquid or other fluent material by impinging jets
    • B05B1/262Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means with means for mechanically breaking-up or deflecting the jet after discharge, e.g. with fixed deflectors; Breaking-up the discharged liquid or other fluent material by impinging jets with fixed deflectors
    • B05B1/265Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means with means for mechanically breaking-up or deflecting the jet after discharge, e.g. with fixed deflectors; Breaking-up the discharged liquid or other fluent material by impinging jets with fixed deflectors the liquid or other fluent material being symmetrically deflected about the axis of the nozzle
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05BSPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B11/00Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use
    • B05B11/01Single-unit hand-held apparatus in which flow of contents is produced by the muscular force of the operator at the moment of use characterised by the means producing the flow
    • B05B11/02Membranes or pistons acting on the contents inside the container, e.g. follower pistons
    • B05B11/026Membranes separating the content remaining in the container from the atmospheric air to compensate underpressure inside the container
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05BSPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B15/00Details of spraying plant or spraying apparatus not otherwise provided for; Accessories
    • B05B15/40Filters located upstream of the spraying outlets
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05BSPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B9/00Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour
    • B05B9/03Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour characterised by means for supplying liquid or other fluent material
    • B05B9/04Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour characterised by means for supplying liquid or other fluent material with pressurised or compressible container; with pump
    • B05B9/08Apparatus to be carried on or by a person, e.g. of knapsack type
    • B05B9/085Apparatus to be carried on or by a person, e.g. of knapsack type with a liquid pump
    • B05B9/0877Apparatus to be carried on or by a person, e.g. of knapsack type with a liquid pump the pump being of pressure-accumulation type or being connected to a pressure accumulation chamber
    • B05B9/0883Apparatus to be carried on or by a person, e.g. of knapsack type with a liquid pump the pump being of pressure-accumulation type or being connected to a pressure accumulation chamber having a discharge device fixed to the container

Definitions

  • the present invention relates to a kit for performing a bronchial challenge test with methacholine comprising a device for delivering a metered amount of an atomized fluid and a methacholine solution or suspension.
  • Asthma is a chronic lung disease caused by inflammation of the airways (with local accumulation of eosinophils) that causes shortness of breath or difficulty in breathing, cough, wheezing or whistling and tightness in the chest. Asthma is particularly widespread among the population, given that it affects on average around 5% of Italians and almost 10% of infants. Moreover, cases in which the subject has the disease without knowing it should be added to these data. In fact, the symptoms of asthma can be misinterpreted or underestimated by the patient, so that a certain percentage of the population tends to ignore the typical symptoms of the disease without giving much importance to the alarm signals sent by the body.
  • the bronchial challenge test is the test that offers the greatest diagnostic accuracy, although with the disadvantage of a high risk of adverse reactions, at times even serious, and high costs in terms of time. For this reason, the bronchial challenge test is performed in closely monitored conditions, with healthcare professionals equipped with drugs such as cortisones, antihistamines and adrenaline; moreover, it is never performed if the patient has suffered from anaphylactic shock or a serious allergic reaction.
  • the challenge test is third level allergy testing, i.e. when an allergy is suspected the patient is first given skin tests (prick tests, patch tests) and, only if the result is inconclusive, goes on to second level testing, based on IGE serum level testing (Prist tests, Rast tests) and then, if necessary, third level testing (bronchial challenge test).
  • the test consists of direct administration of the suspected allergen (specific challenge test) or of other substances (nonspecific challenge test with methacholine or histamine). If, for example, a food allergy is suspected, the allergen (for example egg or peanut protein) is administered orally in dry or freeze-dried form, generally in capsules. If asthma is suspected the allergen is administered by inhalation.
  • specific challenge test for example egg or peanut protein
  • the patient is then kept under observation for a few hours, recording any symptoms objectively, such as size and number of welts, spirometry; in the presence of an allergic reaction some of the most common symptoms are itching, urticaria/angioedema, nausea, vomiting, abdominal pain, diarrhea, dyspnea, cough, rhinorrhea, sneezing, lacrimation, headache, irritability, tension and fatigue.
  • Oral challenge tests can be performed to diagnose allergic reactions to foods or to drugs taken orally.
  • the allergen is administered to the patient starting with a very low dose, which will probably not cause symptoms. At regular intervals of around 30 minutes increasing amounts of allergen are administered until a positive reaction is observed or until a standard amount is reached.
  • the oral challenge test should be performed under double blind conditions; this means that the potential allergen should be flanked by a non-allergenic control substance, known as placebo.
  • the double-blind placebo- controlled food challenge (or DBPCFC) is currently considered the test of reference, or gold standard, for diagnosing food allergies.
  • oral challenge tests Although they are extremely sensitive and specific, oral challenge tests also have some limits. Firstly, they are difficult to perform and can only be conducted in a few specialized centres. The greatest conceptual limit is represented by the fact that they are not always able to reproduce the conditions that occur in the patient's everyday life. A clear example of this concept is food-dependent and exercise-induced anaphylaxis in which patients affected by this form of anaphylaxis have a positive skin test and high IgE levels, but the anaphylactic reaction only occurs if ingestion of the food is followed by physical exercise in a time limit ranging from a few minutes to 3 hours. In similar circumstances, an oral challenge test would give a false negative.
  • the nasal challenge test is used to evaluate allergic conditions such as rhinitis or allergies to airborne substances such as pollens and mites. After administration of the allergen by inhalation (spray) the number of sneezes is counted and the general clinical picture is evaluated. Moreover, sophisticated instruments called rhinomanometers are used to measure the air flow that passes through the nostrils and the resistance to the passage of air. The nasal challenge test is considered positive if a decrease in conductance of at least 20% is recorded. This test is particularly difficult to perform, both due to the equipment used and to the level of participation by the patient in order for the test to be conducted correctly.
  • the bronchial challenge test can be non-specific, i.e. conducted with allergy-causing substances such as histamine or methacholine, or specific, i.e. conducted directly with the allergen.
  • Methacholine is a pharmacological substance capable of causing a slight bronchial obstruction in asthmatic subjects. This substance is instead completely harmless for the rest of the population.
  • the bronchial challenge test with methacholine makes use of this characteristic and consists of performing a series of forced spirometry tests after having inhaled increasing doses of the substance via an atomizer.
  • the methacholine bronchial challenge test is a widely used test in pulmonology, where it is used to study bronchial hyperreactivity.
  • This condition typical in asthmatic subjects, consists of an abnormal bronchoconstrictive response to various stimuli, both internal (moods, emotions) and external to the body (allergens, cold and damp air, physical exertion, viral infections).
  • stimuli both internal (moods, emotions) and external to the body (allergens, cold and damp air, physical exertion, viral infections).
  • bronchial reactivity can also be recorded in obese subjects and in the last months of pregnancy. Besides bronchial asthma, hyperreactivity is also characteristic of other diseases such as COPD (chronic obstructive pulmonary disease), bronchiectasis, atopic dermatitis, allergic and non-allergic rhinitis, cystic fibrosis, cardiac insufficiency and viral infections of the airways.
  • COPD chronic obstructive pulmonary disease
  • bronchiectasis atopic dermatitis
  • allergic and non-allergic rhinitis cystic fibrosis
  • cardiac insufficiency adenobstructive pulmonary disease
  • the methacholine test is a test used mainly to exclude a diagnosis of bronchial asthma rather than to confirm a previously established diagnosis.
  • the negative predictive value of the test is greater than the positive predictive value. In this sense, it is particularly useful when the symptoms, the spirometry and the reversibility test do not confirm or exclude the diagnosis. If asthma is already known, the methacholine test helps to assess the severity of the asthma attack.
  • Methacholine is a synthetic muscarinic agonist of acetylcholine that, at the doses employed in this test, is capable of triggering a small post-inhalation asthma attack in subjects with bronchial hyperresponsiveness. After onset of the attack it can be effectively controlled and resolved by administering a bronchodilator drug by inhalation (spray or aerosol).
  • inhalation spray or aerosol
  • the test provides for the administration by aerosol of increasing doses of methacholine, followed, after each single inhalation, by a spirometry.
  • the results of the spirometry are compared to those of the basal spirometry, performed before starting the test, in order to evaluate any pre-existing bronchial obstruction.
  • a dose-response curve that expresses the degree of bronchial responsiveness of the subject is obtained.
  • the test is interrupted when the dose of methacholine administered causes slight bronchial obstruction (marked by a reduction of 20% or more of the initial FEV1 - spirometry parameter), or after inhalation of the maximum established dose. If considerable bronchial obstruction occurs, the physician administers a bronchodilator (spray or aerosol).
  • Bronchial hyperreactivity indicates an exaggerated response of the airways to broncho- obstructive stimuli of various types and is the basis of all forms of bronchial asthma, regardless of their etiopathogenesis. Therefore, it is a characteristic of bronchial asthma and is closely linked to the mechanisms that cause the disease.
  • COPD chronic obstructive pulmonary disease
  • the Methacholine is appropriately diluted with a buffer solution.
  • the patient is first given a baseline spirometry and subsequently inhales some doses of the buffer (without methacholine), measuring the FEV1 two minutes after inhalation: the value obtained will form the value of reference.
  • the patient is given known doses of methacholine solution, in general around 10 microliters, with a delivery time for each inhalation that varies from 0.6 and 1 second.
  • the inhalations take place every two minutes and the FEV1 is measured 2 minutes after each inhalation.
  • the test is conducted until there is a decrease in FEV1 of over 20 % of the reference value, obtaining the PD20 FEV1.
  • the results can be expressed as provocative concentration (or dose) (PC20FEV1 or PD20FEV1) in mg/ml (or meg) of methacholine.
  • concentration or dose
  • PD20FEV1 PD20FEV1
  • the value is obtained from the dose response curve drawn indicating on the abscissa the concentrations of methacholine and on the ordinate the decreases in FEV1 percentages compared to the reference value.
  • the bronchial challenge test with methacholine is not generally accompanied by important side effects. Due to the mechanism of action of methacholine, in subjects with high hyperreactivity, asthmatic symptoms such as dry cough, breathlessness, chest tightness, sweating and slight tachycardia can occur. In any case, the serial spirometries conducted during the test permit the respiratory parameters to be closely monitored and therefore if the functional monitoring or the symptoms of the patient become significant, the test is suspended immediately and the appropriate asthma treatment is given.
  • the test is considered negative when the PC20FEV1 exceeds 8 mg/ml (or 800-1,000 meg in the case of the PD20FEV1).
  • Bronchial hyperreactivity is present in the majority of asthmatic patients, so that if the bronchial challenge test with methacholine is negative a diagnosis of bronchial asthma is highly unlikely. In fact, some studies have shown that the negative predictive value of the bronchial challenge test is very high (85-95%). On the contrary, the positive predictive value varies from 60% to 82%. This is due to the fact that bronchial hyperreactivity is not only present in asthmatic patients, but can also be caused by other diseases, such as viral infections of the upper airways, cystic fibrosis, gastroesophageal reflux disease and chronic obstructive pulmonary disease.
  • the methacholine test has high sensitivity, as it has very few "false negatives".
  • the validity of the bronchial challenge test with methacholine is influenced by the accuracy of the drug delivery systems and by the accuracy with which the responses are measured.
  • the experience of healthcare professionals, application of the products and correct functioning of the equipment are the main factors that must be checked to obtain standardization of the measurement; moreover, a very relevant factor is represented by the cooperation provided by the patient in order for the test to be conducted correctly.
  • the chemical-physical properties of the methacholine also play a fundamental role in the success of the test, both in terms of its reproducibility and its accuracy.
  • the time recommended for administration of methacholine after preparation of the solutions at increased concentration is around 20 min (duration of the action of the methacholine).
  • the methacholine salt is obtained as a hygroscopic crystalline powder.
  • the powder can be stored at room temperature for over 3 years.
  • High concentration solutions are very stable and can be stored refrigerated at a temperature between 2° and 8°C for over 90 days. Low concentration solutions must be used within a few days or even within 24 hours.
  • Methacholine is mainly marketed in powder form to be reconstituted before use, with which the solutions of increased concentration required to conduct the challenge test can be prepared.
  • the main method used to conduct the challenge test with methacholine is the five breath dosimeter method.
  • 5 solutions of methacholine at different concentrations are prepared in advance in sterile vials and stored in a refrigerator. Before use, the vials must be kept at room temperature for 30 minutes in order to reduce the effects linked to the low temperature of the solution.
  • the means used to perform the inhalations is the aerosol generated by atomizers provided with dosimeter.
  • the doses, of around 10 ⁇ , are administered with a delivery time that varies from 0.3 to 1 second.
  • Control of the FEV1 is recorded via spirometry 60 seconds after administration.
  • the number of deliveries depends on the concentration of methacholine used, on the output of the ampoule and on the inhalation times set.
  • the equipment normally used to perform the challenge test with methacholine i.e. dosimeters and atomizers, can have a negative influence on the test result, in particular due to their structural characteristics, such as atomizer output, aerosol particle dimensions, type and dimensions of the path between atomizer and the patient's mouth, inspiratory flow rate and the apnea time.
  • this equipment must undergo periodic pressure checks and be checked and replaced in order to minimize errors caused by wear.
  • the ampoule of the dosimeter must be replaced frequently with a new calibrated ampoule (after around 40 tests).
  • errors in the test can also be caused by assembly of the equipment and operations for filling with the methacholine solution by healthcare professionals.
  • the administration methods can also influence the results; in fact, due to their bronchoconstrictive effect on asthma sufferers, deep breaths best discriminate these subjects from atopic subjects and rhinitic subjects.
  • Scientific works published have shown that challenge tests with deeper breathing obtained fewer positive tests, higher PD20Fevl and more marked hyperresponsiveness. On the contrary, challenge tests without deep breathing obtained more positive tests, lower PD20Fevl, lower hyperresponsiveness with positive results also in borderline cases.
  • An object of the present invention is therefore to provide a kit for the challenge test with methacholine that can be easily used both by the patient and by healthcare professionals, at the same time reducing any problems linked to the accuracy of administration and handling of methacholine.
  • Another object of the present invention is to provide a kit for the challenge test with methacholine that is ready to use, i.e. that does not require further handling in order to be used correctly and effectively by the patient.
  • Yet another object of the present invention is to provide a device for delivering a metered amount of methacholine in which the doses delivered are easily repeatable and allow a reduction of the dose of substance to be inhaled.
  • Kit comprising:
  • a device for delivering a metered amount of an atomized fluid obtained by delivering an amount of pressurized liquid through atomizing means wherein the device comprises: a chamber for containing a metered amount of a fluid; a replaceable or collapsible fluid reservoir from which said chamber can be charged with fluid; a spring for retaining a predetermined amount of energy and applying it via a piston to the metered amount of fluid in the chamber so as to subject a metered amount of fluid to a predetermined increase in pressure from a lower pressure to a higher pressure of 5 x 10 6 Pa (50 bar) or more, preferably of 10 7 Pa (100 bar) or more, so as to permit delivery of said metered amount of fluid from said chamber at said higher pressure; and atomizing means for atomizing the fluid delivered from said chamber;
  • the atomizing means of the device contained in the kit comprise an outlet aperture having a hydraulic diameter from 1 to 100 ⁇ , preferably from 1 to 50 ⁇ .
  • the concentration of the methacholine solution or suspension is from 0.01 mg/ml to 200 ml/mg, even more preferably from 0.02 to lOOml/mg.
  • the application of said predetermined amount of energy to the fluid in the device contained in the kit starts the discharge of the fluid from said chamber.
  • the device contained in the kit is provided with means to retain said spring in a state retaining said predetermined amount of energy, and actuation means for releasing said predetermined amount of energy from said spring.
  • the piston acted on by said spring of the device contained in the kit according to the present description is part of a pump mechanism and said chamber is provided as the cylinder space in the pump mechanism beyond the pump piston.
  • the pump mechanism of the device contained in the kit is provided with a mechanism whereby the pump can be held in the cocked state prior to release of the energy from the spring.
  • the piston of the device is hollow and provides a channel for fluid to enter the chamber. Moreover, the channel is provided with non-return inlet valve means for the chamber.
  • the chamber of the device according to the present description is a variable volume chamber with non-return inlet valve means and non-return outlet valve means to permit repeated charge of fluid into said chamber and discharge of fluid from said chamber.
  • the atomizing means of the device contained in the kit comprise an outlet aperture arranged to form a jet of the fluid and an impingement body which is located in the line of trajectory of the jet of fluid and which is arranged to cause breakup of the jet of fluid into a spray of droplets.
  • a further aspect of the invention is represented by a device for delivering a metered amount of an atomized fluid obtained by delivering an amount of pressurized liquid through atomizing means.
  • the device comprises: a chamber for containing a metered amount of a fluid; a replaceable or collapsible fluid reservoir from which said chamber can be charged with fluid; a spring for retaining a predetermined amount of energy and applying it via a piston to the metered amount of fluid in the chamber so as to subject a metered amount of fluid to a predetermined increase in pressure from a lower pressure to a higher pressure of 5 x 10 6 Pa (50 bar) or more, so as to permit delivery of said metered amount of fluid from said chamber at said higher pressure and atomizing means for atomizing the fluid delivered from said chamber, characterized in that said reservoir contains a methacholine solution or suspension in a concentration from 0.01 mg/ml to 200 mg/ml.
  • Fig. 1 is a sectional view of an inhalation device of metered doses according to the present description, with the methacholine solution to be distributed contained in a collapsible bag removably mounted in the device.
  • Fig. 2 is a sectional view of part of an alternative inhalation device of metered doses, wherein a product to be distributed is contained in a collapsible tube with a nozzle that acts as piston.
  • Fig. 3 is an enlarged detailed view of an example of an atomizer orifice assembly.
  • Fig. 4 schematically illustrates an alternative atomizer device.
  • Fig. 5 schematically illustrates another alternative atomizer device.
  • the kit for performing the challenge test with methacholine comprises an aqueous solution or suspension of methacholine in a concentration from O.Olmg/ml to 200 mg/ml, preferably from 0.01 mg/ml to 100 mg/ml and even more preferably from 0.02 mg/ml to 80mg/ml.
  • the methacholine solution or suspension is prepared in advance and made up so as to obtain different solutions to perform the various reactivity tests as described above.
  • the kit also comprises a device for delivering a metered amount of methacholine solution or suspension, which will be illustrated below.
  • the device comprises a body in which a cylinder 2 with a circular section is defined, in which a piston 3 is mounted to perform a back-and-forth motion.
  • the cylinder 2 communicates with a metering chamber 4 having a reduced section.
  • the piston 3 has a part with reduced diameter 5 that engages in a fluid-tight manner inside the metering chamber 4, by means of a cap or seal ring made of plastic material (such as PTFE or nylon) fitted to the part of the piston 5.
  • the seal means or gasket can be formed in one piece with the part with reduced diameter 5 of the piston, for example in the form of cap, rib or enlarged rim.
  • a precharged compression spring 6 is located in the cylinder 2, between the enlarged head of the piston 3 and a wall of the opposite end of the cylinder 2.
  • An actuation rod 31 is connected to the piston 3, passes through the spring 6 and through a passage 34 in the body 1, to exit from the body 1.
  • a handle 32 is provided to move the rod 31 and the piston 3.
  • the end of the rod 31 can be connected to a mechanism, such as a lever mechanism, so that the user can easily actuate the device in opposition to the compression force of the spring 6.
  • a bolt device 33 provided on the body engages with the rod 31 to block the rod 31 in a charged position, according to the illustration in Fig. 1.
  • An actuation or release button 35 is provided to release the bolt device 33.
  • a cavity 15 is defined inside the body 1 in which a collapsible bag 10 or a replaceable reservoir containing the methacholine solution or suspension is located.
  • a door 16 on the side of the body 1 can be opened to change the collapsible bag 10 or the reservoir.
  • the inside of the bag 10 communicates with an inlet passage, which in turn communicates with the chamber 4 via a non-return valve 13.
  • the chamber 4 is connected to an outlet passage 21 that extends from the chamber 4 to an atomizing head 22, via a non-return valve 23 and a pressure release valve 25.
  • the body 1 can be provided with a mouthpiece 40, which creates an atomizing chamber around the atomizing head 22.
  • the pressure of the fluid in the chamber 4 develops rapidly so as to exceed the limit value of the pressure release valve 25, and the fluid is then ejected under a high pressure through the outlet passage 21 to the atomizing head 22, through the non-return valve 23.
  • the non-return valve 13 prevents the fluid from returning into the bag 10, through the inlet passage 11.
  • the optional mouthpiece 40 provides an atomizing chamber inside which the fine mist is enclosed, facilitating the inhalation thereof.
  • the rod 31 is drawn back by means of the handle 32 in opposition to the elastic force of the spring 6.
  • the bolt 33 automatically blocks the rod 31 in a locked end position.
  • the fluid is drawn from the collapsible bag 10 into the pressurized chamber 4, through the inlet passage 11 and the non-return valve 13.
  • the non-return valve 23 prevents air from being drawn into the pressurized chamber 4 through the outlet passage 21. Due to blocking of the rod 31, the fluid in the pressurized chamber 4 is maintained at ambient pressure and there is little or no risk of loss of fluid from the chamber.
  • Actuation of the bolt device 33 provides the user with a clear indication of when the piston 3 has completed the desired movement inside the cylinder 2 and the required dose of fluid has been received. If the user does not draw back the rod 31 sufficiently, the bolt device 33 will not engage and the user will detect the elastic force to the spring 6 and will know that the rod 31 must be drawn back further. Consequently, the bolt device 33 provides both means for retaining fluid in the chamber 4 at ambient pressure, and means for warning the user of the incomplete actuation of the device, thereby reducing the risk of variable actuation of the device.
  • the delivery device is once again in a charged position, as illustrated in Fig. 1, ready to be actuated.
  • a metered dose of fluid product is pressurized and atomized in an extremely precise and repeatable way.
  • a metered amount of fluid product will be drawn into the pressurized chamber 4.
  • the piston 3 will be urged forward so as to impart a predetermined amount of energy, and consequently increase its pressure to a predetermined extent. Consequently, as the pressurized fluid is ejected through the atomizing head 22 having predetermined atomizing properties, the fluid will be atomized in a fine mist having a predetermined average size of the droplets, without the use of a propellant or of other liquefied gases.
  • a very high pressure must be applied to the fluid in the chamber 4.
  • the capacity of the chamber 4 can be 20 microliters; and the diameter of the small end 5 of the piston 3 can be 2 mm; the diameter of the cylinder 2 can be 15 mm, the force of the spring 6 can be 100 newtons, and the atomizing head 22 can have an outlet orifice with a diameter from 3 to 15 ⁇ .
  • a pressure of the order of 4 x 10 7 P (400) bar can be generated in the fluid in the chamber 4.
  • the cavity 15 can be in communication with the atmosphere and can be at atmospheric pressure.
  • the cavity 15 can be pressurized to above atmospheric pressure, which contributes to forcing the content of the collapsible bag 10 to enter the chamber 4 without the need to create subatmospheric pressures in the chamber 4. This can contribute to avoiding the formation of gas bubbles in the fluid sucked into the chamber 4.
  • the pressure release valve 25 and the non-return valve 23 can be combined as a single assembly.
  • a practical embodiment can have a different structure; for example, a lever mechanism or other gear mechanism can be used to facilitate charging of the piston 3 in opposition to the spring 6.
  • the delivery device can be provided with a cover, which when opened, automatically charges the piston 3 and blocks the bolt device 33, so that the delivery device is ready to operate.
  • the delivery device could be operated by actuating the button 35, when the cover is opened.
  • the piston 3 can be charged in opposition to the spring 6 and the bolt device 33 can be blocked, while a cover of the delivery device is closed. Consequently, the device is precharged and can be operated immediately after opening of the cover.
  • opening of a cover of the device can automatically charge the piston 3 in opposition with the spring 6, block the bolt device 33, and then automatically release the bolt device 33 at the end of the opening action of the cover, so that blocking is only transitory.
  • the delivery device of Fig. 1 preferably has small dimensions. As, unlike known delivery devices, it does not require to provide a large volume to contain a pressurized liquefied gaseous propellant, it can be easily produced in small dimensions.
  • the container of the product in the form of collapsible bag 10, can contain a much larger amount of drug compared to conventional delivery devices.
  • conventional delivery devices could be limited to 200-400 doses
  • a delivery device constructed according to the lines illustrated in Fig. 1 can easily contain 1000 or more doses, in the collapsible bag 10. It is also understood that the content of the bag 10 is protected from atmospheric pollution and actuation of the device takes place by atomizing the fluid in the chamber 4 without the use of a jet of air, and therefore the device operates as an airless spray device.
  • the bag 10 When the bag 10 is empty, it can simply be removed from the cavity 15 and replaced with a new bag.
  • the bag 10 preferably comprises a gasket to prevent product from escaping from the bag 10, unless the bag 10 is connected to a connector, such as 12.
  • a part of the piston or valve system can be disposable, together with the product receptacle such as the collapsible bag 10. It must be understood that, in use of the delivery device illustrated, there is nothing that stops discharge of the content of the chamber 4 in the form of atomized fluid, once the actuation button 35 has been pressed to disengage the bolt device 33 and consequently to disengage the spring 6.
  • the amount of energy applied by the spring 6 to the metered amount of fluid in the pressurized chamber 4 is determined in an absolute manner, so that the increase in pressure to which the metered amount of fluid is subjected is also predetermined in an absolute manner.
  • Another feature of the delivery device of Fig. 1 is that the metered amount of fluid in the chamber 4 is subjected to an increase in pressure only when the actuation button 35 has been pressed to disengage the bolt device 33 and consequently disengage the spring 6.
  • This offers the advantage that no gasket or other means are required to condition the highly pressurize fluid, before the atomizing stroke.
  • the increase in pressure applied by the spring 6 and by the piston 3 to the metered amount of fluid in the chamber 4 causes the pressurized fluid to pass through the atomizing head 22, to be atomized thereby. This objective is achieved in all the other illustrated embodiments of the invention described below.
  • FIG. 1 Another important advantage of the delivery device of Fig. 1 is that, by pressing the actuation button 35 to disengage the bolt device 33 and the spring 6, the atomizing head 22 does not move inside the body 1, but only the button 35 moves. This makes it easier to direct the atomized fluid precisely, and is in contrast to a conventional vertical axis finger-operated pump system, in which the atomizing nozzle is depressed to trigger atomizing. This would be disadvantageous in an inhaler for medical use, as it would be difficult to direct the atomized fluid precisely.
  • the stroke of the piston 3 is fixed; if desired, means can be provided to vary the stroke of the piston. These means are preferably calibrated, so that the user can adjust the delivery device as required to deliver different amounts of atomized fluid. Once the adjustment means have been set to a specific value, the MDI will then provide a metered dose of mist in a highly repeatable manner, exactly as if the stroke of the piston were fixed.
  • Fig. 1 The device of Fig. 1 has been described in terms of a device in which the cylinder of the pump mechanism is static and the piston moves axially therein. However, it is possible for the cylinder to be carried on the rod 31 and the piston to be fixed.
  • a fluid product 50 is contained in a collapsible tube 51 that is formed in one piece with an extended nozzle 52 that acts as a piston.
  • the nozzle/piston 52 is positioned so as to perform a back-and-forth motion inside a cylinder 53.
  • a simple nonreturn valve 54 is incorporated at the end of the nozzle/piston 52.
  • a metering chamber 55 is defined at the end of the cylinder 53, and communicates via a simple non-return valve 56 with an atomizing head 57.
  • the cylinder 53, the non-return valve 56 and the atomizing head 57 are all contained in a casing 58, which is formed with annular ribs 59, which serve to position the casing 58 in a first part of main body 60.
  • the upper part of the tube 51 is formed with an annular rib 61, which serves to position the tube 51 in a second part of main body 62.
  • An elastic force device is provided to urge the two parts of main body 60 and 62 toward each other.
  • a bolt device is provided to block the two parts of main body 60, 62 at a predetermined distance from each other, in a charged condition, and an actuation device is provided to release the bolt device.
  • the embodiment of Fig. 2 functions as follows.
  • the delivery device is in an uncharged or "ready for use” condition.
  • an appropriate charging mechanism such as a lever mechanism
  • the parts of main body 60 and 62 are moved away from each other so that the nozzle/piston 52 is drawn back with respect to the cylinder 53.
  • the depressurization in the chamber 55 causes the fluid product 50 to be drawn from the tube 51, via the non-return valve 54, to fill the chamber 55.
  • the non-return valve 56 serves to prevent air from entering the chamber 55 from the atomizing assembly 57.
  • the bolt device operates in the sense of keeping the parts of main body 60, 62 at a distance from each other in predetermined relative positions. Releasing the bolt device via the actuation device, due to the force device the nozzle/piston 52 is urged suddenly to enter the cylinder 53 to apply a sudden pressure to the fluid product 50 in the chamber 55, in a generally similar manner to that described in the embodiment of Fig. 1. The pressurized fluid product is then ejected under pressure into the atomizing assembly 57, via the non-return valve 56, and is then atomized by the atomizing assembly 57 to provide a fine mist.
  • Fig. 2 operates in a generally similar manner to that of the embodiment of Fig. 1.
  • the product 50 is provided with the tube 51 which, together with the piston nozzle 52 and with the simple non-return valve 54, can be changed as a complete disposable assembly.
  • the tube 51 for the product and its integral nozzle 52 and the non-return valve 54 can be made easily and relatively inexpensively of plastic materials. The user is protected from contact with the fluid product 50, unless the delivery device is not actuated correctly.
  • one or other of the parts 60, 62 can be fixed in relation to a main body of the delivery device, the other of the parts 60 and 62 thus being movable with respect to the fixed part.
  • both the parts 60 and 62 can be movable with respect to a main body of the delivery device.
  • FIG. 3 shows, in an enlarged detail, an example of an atomizing head assembly 80.
  • An inlet passage 81 formed in a body 82 leads to an inlet chamber 83.
  • a filter 84 is interposed between successive sections of the inlet chamber 83.
  • the final section of the inlet chamber 83 leads to a whirling chamber 85, which in turn leads to a nozzle 86.
  • the object of the filter 84 is to prevent the particles from blocking the final orifice.
  • the filter 84 can be made of stainless steel mesh, having a mesh size ranging from 1 to 10 ⁇ , preferably 3 ⁇ .
  • the diameter of the outlet orifice is preferably less than 100 ⁇ .
  • the diameter of the droplets preferably ranges from 1 to 20 ⁇ , and more preferably from 3 to 10 ⁇ .
  • a jet of fluid 102 can be produced through an outlet orifice 104 by high speed impact on an object such as a metal sphere 106, which can cause atomizing of the fluid.
  • FIG. 8 Another alternative configuration is shown in Fig. 8, where two high speed and high pressure jets of fluid 110 are brought together, so that the fluid is atomized in the point in which they meet.
  • the object of the examples is to characterize with measurable physical parameters the differences between the common dispensers and the dispenser described in the present description from the point of view of emission of the active compound.
  • Effectiveness for permitting inhalation of a sufficient amount of respirable active substance with particles ⁇ 6 ⁇ ; effectiveness must be independent of the airflow generated by the patient.
  • Reproducibility i.e. the capacity to deliver doses always with the same amount and respirable fraction.
  • Stability i.e. the fact that the inhalation composition present inside it remains unchanged over a long period of time.
  • Ease of use i.e. the device must be easy to use even in critical phases, must be pocket sized, light and easy to transport, and also must be multidose, i.e. it must allow the delivery of numerous doses of the composition contained therein.
  • the aforesaid characteristics are a function of the constructional characteristics of the single dispensers. These can differ greatly based on the type of dispenser considered, and can condition, even significantly, the effect of the inhalatory response. In fact, the difficulty and limits encountered by the patient in performing effective inhalation are based on these possible differences in delivery effectiveness.
  • MDI Metal Dose Inhaler
  • devices of the MDI Metal Dose Inhaler
  • MDIs all have some common strengths and weaknesses.
  • the main problems of these dispensers are linked to the fact that they are highly dependent on the cognitive capacity and on the physical ability of the patient, as in order to perform delivery/inhalation, perfect coordination by the patient is required. In fact, the patient must, in sequence, start actuation of the spray from the dispenser and simultaneously breathe deeply to inhale the active substance. The time available between these two actions varies from 290 to 400 msec.
  • the three MDI dispensers used for comparison were three dispensers marketed with the brands Aliflus ® , Flutiformo ® and Ventolin ® .
  • Tables 1 and 2 below illustrate the data relating to the dispenser of to the kit according to the present invention.
  • Tables 3, 4, 5, 6, 7 and 8 illustrate the data of the MDI dispensers for comparison.

Abstract

A kit to perform the bronchial challenge test with methacholine comprising a device for delivering a metered amount of an atomized fluid and a methacholine solution or suspension. The delivery device comprises a chamber (4) for containing the fluid, a replaceable or collapsible reservoir (10), a spring (6) for retaining a predetermined amount of energy and applying it via a piston (3) to the fluid contained in the chamber so as to subject the fluid to an increase in pressure from a lower pressure to a higher pressure so as so as to permit delivery of the fluid from the chamber at high pressure. The device also comprises atomizing means (22) for atomizing the fluid delivered from the chamber.

Description

"KIT FOR PERFORMING A BRONCHIAL CHALLENGE TEST WITH
METHACHOLINE AND DEVICE CONTAINING METHACHOLINE"
DESCRIPTION
The present invention relates to a kit for performing a bronchial challenge test with methacholine comprising a device for delivering a metered amount of an atomized fluid and a methacholine solution or suspension.
Asthma is a chronic lung disease caused by inflammation of the airways (with local accumulation of eosinophils) that causes shortness of breath or difficulty in breathing, cough, wheezing or whistling and tightness in the chest. Asthma is particularly widespread among the population, given that it affects on average around 5% of Italians and almost 10% of infants. Moreover, cases in which the subject has the disease without knowing it should be added to these data. In fact, the symptoms of asthma can be misinterpreted or underestimated by the patient, so that a certain percentage of the population tends to ignore the typical symptoms of the disease without giving much importance to the alarm signals sent by the body.
Although there are several methods of diagnosing asthma, of all the allergy tests, the bronchial challenge test is the test that offers the greatest diagnostic accuracy, although with the disadvantage of a high risk of adverse reactions, at times even serious, and high costs in terms of time. For this reason, the bronchial challenge test is performed in closely monitored conditions, with healthcare professionals equipped with drugs such as cortisones, antihistamines and adrenaline; moreover, it is never performed if the patient has suffered from anaphylactic shock or a serious allergic reaction.
The challenge test is third level allergy testing, i.e. when an allergy is suspected the patient is first given skin tests (prick tests, patch tests) and, only if the result is inconclusive, goes on to second level testing, based on IGE serum level testing (Prist tests, Rast tests) and then, if necessary, third level testing (bronchial challenge test).
The test consists of direct administration of the suspected allergen (specific challenge test) or of other substances (nonspecific challenge test with methacholine or histamine). If, for example, a food allergy is suspected, the allergen (for example egg or peanut protein) is administered orally in dry or freeze-dried form, generally in capsules. If asthma is suspected the allergen is administered by inhalation. The patient is then kept under observation for a few hours, recording any symptoms objectively, such as size and number of welts, spirometry; in the presence of an allergic reaction some of the most common symptoms are itching, urticaria/angioedema, nausea, vomiting, abdominal pain, diarrhea, dyspnea, cough, rhinorrhea, sneezing, lacrimation, headache, irritability, tension and fatigue.
Oral challenge tests can be performed to diagnose allergic reactions to foods or to drugs taken orally. The allergen is administered to the patient starting with a very low dose, which will probably not cause symptoms. At regular intervals of around 30 minutes increasing amounts of allergen are administered until a positive reaction is observed or until a standard amount is reached. In order to obtain maximum diagnostic reliability, the oral challenge test should be performed under double blind conditions; this means that the potential allergen should be flanked by a non-allergenic control substance, known as placebo. The double-blind placebo- controlled food challenge (or DBPCFC) is currently considered the test of reference, or gold standard, for diagnosing food allergies.
Although they are extremely sensitive and specific, oral challenge tests also have some limits. Firstly, they are difficult to perform and can only be conducted in a few specialized centres. The greatest conceptual limit is represented by the fact that they are not always able to reproduce the conditions that occur in the patient's everyday life. A clear example of this concept is food-dependent and exercise-induced anaphylaxis in which patients affected by this form of anaphylaxis have a positive skin test and high IgE levels, but the anaphylactic reaction only occurs if ingestion of the food is followed by physical exercise in a time limit ranging from a few minutes to 3 hours. In similar circumstances, an oral challenge test would give a false negative.
The nasal challenge test is used to evaluate allergic conditions such as rhinitis or allergies to airborne substances such as pollens and mites. After administration of the allergen by inhalation (spray) the number of sneezes is counted and the general clinical picture is evaluated. Moreover, sophisticated instruments called rhinomanometers are used to measure the air flow that passes through the nostrils and the resistance to the passage of air. The nasal challenge test is considered positive if a decrease in conductance of at least 20% is recorded. This test is particularly difficult to perform, both due to the equipment used and to the level of participation by the patient in order for the test to be conducted correctly.
The bronchial challenge test can be non-specific, i.e. conducted with allergy-causing substances such as histamine or methacholine, or specific, i.e. conducted directly with the allergen.
Methacholine is a pharmacological substance capable of causing a slight bronchial obstruction in asthmatic subjects. This substance is instead completely harmless for the rest of the population. The bronchial challenge test with methacholine makes use of this characteristic and consists of performing a series of forced spirometry tests after having inhaled increasing doses of the substance via an atomizer.
The methacholine bronchial challenge test (MBCT) is a widely used test in pulmonology, where it is used to study bronchial hyperreactivity. This condition, typical in asthmatic subjects, consists of an abnormal bronchoconstrictive response to various stimuli, both internal (moods, emotions) and external to the body (allergens, cold and damp air, physical exertion, viral infections). By virtue of this response, the airways tend to close too easily and too much, due to stimuli that, at the same doses, do not cause significant responses in normal subjects.
Excessive bronchial reactivity can also be recorded in obese subjects and in the last months of pregnancy. Besides bronchial asthma, hyperreactivity is also characteristic of other diseases such as COPD (chronic obstructive pulmonary disease), bronchiectasis, atopic dermatitis, allergic and non-allergic rhinitis, cystic fibrosis, cardiac insufficiency and viral infections of the airways.
However, the diagnostic significance of the methacholine test remains prevalently linked to the study of bronchial asthma. Its widespread use in clinical practice is given by the high reproducibility of the results and high level of safety, with low risk of systemic side effects. Moreover, the test has high diagnostic sensitivity. The methacholine test is a test used mainly to exclude a diagnosis of bronchial asthma rather than to confirm a previously established diagnosis.
In fact, the negative predictive value of the test is greater than the positive predictive value. In this sense, it is particularly useful when the symptoms, the spirometry and the reversibility test do not confirm or exclude the diagnosis. If asthma is already known, the methacholine test helps to assess the severity of the asthma attack.
Methacholine is a synthetic muscarinic agonist of acetylcholine that, at the doses employed in this test, is capable of triggering a small post-inhalation asthma attack in subjects with bronchial hyperresponsiveness. After onset of the attack it can be effectively controlled and resolved by administering a bronchodilator drug by inhalation (spray or aerosol). To evaluate and quantify the degree of bronchial reactivity, the test provides for the administration by aerosol of increasing doses of methacholine, followed, after each single inhalation, by a spirometry. The results of the spirometry are compared to those of the basal spirometry, performed before starting the test, in order to evaluate any pre-existing bronchial obstruction. In this way a dose-response curve that expresses the degree of bronchial responsiveness of the subject is obtained. The lower the dose of methacholine capable of causing bronchoconstriction is, the higher the degree of bronchial hyperresponsiveness will be. The test is interrupted when the dose of methacholine administered causes slight bronchial obstruction (marked by a reduction of 20% or more of the initial FEV1 - spirometry parameter), or after inhalation of the maximum established dose. If considerable bronchial obstruction occurs, the physician administers a bronchodilator (spray or aerosol).
Bronchial hyperreactivity indicates an exaggerated response of the airways to broncho- obstructive stimuli of various types and is the basis of all forms of bronchial asthma, regardless of their etiopathogenesis. Therefore, it is a characteristic of bronchial asthma and is closely linked to the mechanisms that cause the disease.
However, it can be encountered in other diseases, in particular in chronic obstructive pulmonary disease (COPD), in the presence of bronchiectasis, in the presence of viral infections of the upper airways, of rhinitis, especially persistent, and in congestive heart failure.
It can also be encountered in pregnancy or obesity, for reasons linked to respiratory dynamics. To show the presence of this bronchial hyperreactivity, the airways must be exposed to a triggering factor: if this hyperreactivity is present, there will be a reduction in the volume of the air exhaled in the first second, called FEV1.
The methods of performing the bronchial challenge test with methacholine are described below.
In the first step of the test, the Methacholine is appropriately diluted with a buffer solution. The patient is first given a baseline spirometry and subsequently inhales some doses of the buffer (without methacholine), measuring the FEV1 two minutes after inhalation: the value obtained will form the value of reference. Subsequently, the patient is given known doses of methacholine solution, in general around 10 microliters, with a delivery time for each inhalation that varies from 0.6 and 1 second. The inhalations take place every two minutes and the FEV1 is measured 2 minutes after each inhalation. The test is conducted until there is a decrease in FEV1 of over 20 % of the reference value, obtaining the PD20 FEV1.
The results can be expressed as provocative concentration (or dose) (PC20FEV1 or PD20FEV1) in mg/ml (or meg) of methacholine. The value is obtained from the dose response curve drawn indicating on the abscissa the concentrations of methacholine and on the ordinate the decreases in FEV1 percentages compared to the reference value.
The bronchial challenge test with methacholine is not generally accompanied by important side effects. Due to the mechanism of action of methacholine, in subjects with high hyperreactivity, asthmatic symptoms such as dry cough, breathlessness, chest tightness, sweating and slight tachycardia can occur. In any case, the serial spirometries conducted during the test permit the respiratory parameters to be closely monitored and therefore if the functional monitoring or the symptoms of the patient become significant, the test is suspended immediately and the appropriate asthma treatment is given.
On rare occasions, severe bronchospasm can occur, as can cardiovascular pharmacological effects (decrease in blood pressure) and gastrointestinal pharmacological effects (increase in gastrointestinal motility with possible diarrhea).
In clinical practice the test is considered negative when the PC20FEV1 exceeds 8 mg/ml (or 800-1,000 meg in the case of the PD20FEV1).
Bronchial hyperreactivity is present in the majority of asthmatic patients, so that if the bronchial challenge test with methacholine is negative a diagnosis of bronchial asthma is highly unlikely. In fact, some studies have shown that the negative predictive value of the bronchial challenge test is very high (85-95%). On the contrary, the positive predictive value varies from 60% to 82%. This is due to the fact that bronchial hyperreactivity is not only present in asthmatic patients, but can also be caused by other diseases, such as viral infections of the upper airways, cystic fibrosis, gastroesophageal reflux disease and chronic obstructive pulmonary disease.
Moreover, it must be stressed that the methacholine test has high sensitivity, as it has very few "false negatives".
The validity of the bronchial challenge test with methacholine is influenced by the accuracy of the drug delivery systems and by the accuracy with which the responses are measured. In fact, the experience of healthcare professionals, application of the products and correct functioning of the equipment are the main factors that must be checked to obtain standardization of the measurement; moreover, a very relevant factor is represented by the cooperation provided by the patient in order for the test to be conducted correctly.
The chemical-physical properties of the methacholine also play a fundamental role in the success of the test, both in terms of its reproducibility and its accuracy. In particular, attention must be given to the storage conditions of the methacholine, which can undergo degradation processes that alter the quality and the concentration of the solution and invalidate the results of the tests conducted. In this regard, the time recommended for administration of methacholine after preparation of the solutions at increased concentration is around 20 min (duration of the action of the methacholine).
The methacholine salt is obtained as a hygroscopic crystalline powder. The powder can be stored at room temperature for over 3 years.
High concentration solutions (pH>6) are very stable and can be stored refrigerated at a temperature between 2° and 8°C for over 90 days. Low concentration solutions must be used within a few days or even within 24 hours.
Methacholine is mainly marketed in powder form to be reconstituted before use, with which the solutions of increased concentration required to conduct the challenge test can be prepared.
The main method used to conduct the challenge test with methacholine is the five breath dosimeter method. With this method, 5 solutions of methacholine at different concentrations are prepared in advance in sterile vials and stored in a refrigerator. Before use, the vials must be kept at room temperature for 30 minutes in order to reduce the effects linked to the low temperature of the solution.
The actual test is preceded by inhalation of a diluent or placebo in order to record the patient's behaviour and "calibrate" the equipment. To obtain a reproducible measurement it is essential not to re-use any solution remaining in the atomizer, as it could have a different concentration due to evaporation.
The means used to perform the inhalations is the aerosol generated by atomizers provided with dosimeter. The doses, of around 10 μΐ, are administered with a delivery time that varies from 0.3 to 1 second. Control of the FEV1 is recorded via spirometry 60 seconds after administration. The number of deliveries depends on the concentration of methacholine used, on the output of the ampoule and on the inhalation times set.
The equipment normally used to perform the challenge test with methacholine, i.e. dosimeters and atomizers, can have a negative influence on the test result, in particular due to their structural characteristics, such as atomizer output, aerosol particle dimensions, type and dimensions of the path between atomizer and the patient's mouth, inspiratory flow rate and the apnea time.
Moreover, this equipment must undergo periodic pressure checks and be checked and replaced in order to minimize errors caused by wear. For example, the ampoule of the dosimeter must be replaced frequently with a new calibrated ampoule (after around 40 tests). Moreover, errors in the test can also be caused by assembly of the equipment and operations for filling with the methacholine solution by healthcare professionals.
Further, the administration methods can also influence the results; in fact, due to their bronchoconstrictive effect on asthma sufferers, deep breaths best discriminate these subjects from atopic subjects and rhinitic subjects. Scientific works published have shown that challenge tests with deeper breathing obtained fewer positive tests, higher PD20Fevl and more marked hyperresponsiveness. On the contrary, challenge tests without deep breathing obtained more positive tests, lower PD20Fevl, lower hyperresponsiveness with positive results also in borderline cases.
Therefore, it would be desirable to provide a kit for performing the challenge test with methacholine capable of overcoming the problems listed above regarding management of the methacholine and management of the equipment.
It would also be desirable to provide a kit for the challenge test with methacholine that allows simple use both by the patient and by the healthcare professional performing the test.
It would also be desirable to provide a kit for the challenge test with methacholine that can be used directly without the need to perform handling and dilutions of the methacholine, thereby avoiding the risk of errors of pollution of the samples or of concentration.
It would also be desirable to provide a device for delivering a metered amount of methacholine that can be easily inhaled by the patient, even when this latter is not particularly cooperative, such as in the case of children or the elderly.
It would also be desirable to provide a device for delivering a metered amount of methacholine to perform the challenge test, which allows the use of a limited amount of substance to be inhaled, reducing possible further adverse effects with respect to the bronchoconstrictive effect of the methacholine itself.
An object of the present invention is therefore to provide a kit for the challenge test with methacholine that can be easily used both by the patient and by healthcare professionals, at the same time reducing any problems linked to the accuracy of administration and handling of methacholine.
Another object of the present invention is to provide a kit for the challenge test with methacholine that is ready to use, i.e. that does not require further handling in order to be used correctly and effectively by the patient.
Yet another object of the present invention is to provide a device for delivering a metered amount of methacholine in which the doses delivered are easily repeatable and allow a reduction of the dose of substance to be inhaled.
The aforesaid and other objects and advantages of the present invention, which will be apparent from the description below, are achieved by means of a Kit comprising:
• a device for delivering a metered amount of an atomized fluid obtained by delivering an amount of pressurized liquid through atomizing means, wherein the device comprises: a chamber for containing a metered amount of a fluid; a replaceable or collapsible fluid reservoir from which said chamber can be charged with fluid; a spring for retaining a predetermined amount of energy and applying it via a piston to the metered amount of fluid in the chamber so as to subject a metered amount of fluid to a predetermined increase in pressure from a lower pressure to a higher pressure of 5 x 106 Pa (50 bar) or more, preferably of 107 Pa (100 bar) or more, so as to permit delivery of said metered amount of fluid from said chamber at said higher pressure; and atomizing means for atomizing the fluid delivered from said chamber;
• a methacholine solution or suspension in a concentration from 0.02mg/ml to 200mg/ml.
Preferably, the atomizing means of the device contained in the kit comprise an outlet aperture having a hydraulic diameter from 1 to 100 μιη, preferably from 1 to 50 μιη.
Preferably, the concentration of the methacholine solution or suspension is from 0.01 mg/ml to 200 ml/mg, even more preferably from 0.02 to lOOml/mg.
Preferably, the application of said predetermined amount of energy to the fluid in the device contained in the kit starts the discharge of the fluid from said chamber.
Preferably, the device contained in the kit is provided with means to retain said spring in a state retaining said predetermined amount of energy, and actuation means for releasing said predetermined amount of energy from said spring.
The piston acted on by said spring of the device contained in the kit according to the present description is part of a pump mechanism and said chamber is provided as the cylinder space in the pump mechanism beyond the pump piston.
Preferably, the pump mechanism of the device contained in the kit is provided with a mechanism whereby the pump can be held in the cocked state prior to release of the energy from the spring.
The piston of the device is hollow and provides a channel for fluid to enter the chamber. Moreover, the channel is provided with non-return inlet valve means for the chamber.
Preferably the chamber of the device according to the present description is a variable volume chamber with non-return inlet valve means and non-return outlet valve means to permit repeated charge of fluid into said chamber and discharge of fluid from said chamber.
According to the present description, the atomizing means of the device contained in the kit comprise an outlet aperture arranged to form a jet of the fluid and an impingement body which is located in the line of trajectory of the jet of fluid and which is arranged to cause breakup of the jet of fluid into a spray of droplets.
A further aspect of the invention is represented by a device for delivering a metered amount of an atomized fluid obtained by delivering an amount of pressurized liquid through atomizing means. The device comprises: a chamber for containing a metered amount of a fluid; a replaceable or collapsible fluid reservoir from which said chamber can be charged with fluid; a spring for retaining a predetermined amount of energy and applying it via a piston to the metered amount of fluid in the chamber so as to subject a metered amount of fluid to a predetermined increase in pressure from a lower pressure to a higher pressure of 5 x 106 Pa (50 bar) or more, so as to permit delivery of said metered amount of fluid from said chamber at said higher pressure and atomizing means for atomizing the fluid delivered from said chamber, characterized in that said reservoir contains a methacholine solution or suspension in a concentration from 0.01 mg/ml to 200 mg/ml.
Further features and advantages of the present invention will be more apparent from the description of preferred embodiments of the delivery device, illustrated by way of non- limiting example in the accompanying figures, wherein:
Fig. 1 is a sectional view of an inhalation device of metered doses according to the present description, with the methacholine solution to be distributed contained in a collapsible bag removably mounted in the device.
Fig. 2 is a sectional view of part of an alternative inhalation device of metered doses, wherein a product to be distributed is contained in a collapsible tube with a nozzle that acts as piston.
Fig. 3 is an enlarged detailed view of an example of an atomizer orifice assembly.
Fig. 4 schematically illustrates an alternative atomizer device.
Fig. 5 schematically illustrates another alternative atomizer device.
According to the present invention, the kit for performing the challenge test with methacholine comprises an aqueous solution or suspension of methacholine in a concentration from O.Olmg/ml to 200 mg/ml, preferably from 0.01 mg/ml to 100 mg/ml and even more preferably from 0.02 mg/ml to 80mg/ml. The methacholine solution or suspension is prepared in advance and made up so as to obtain different solutions to perform the various reactivity tests as described above.
The kit also comprises a device for delivering a metered amount of methacholine solution or suspension, which will be illustrated below.
As illustrated in Fig. 1, the device comprises a body in which a cylinder 2 with a circular section is defined, in which a piston 3 is mounted to perform a back-and-forth motion. The cylinder 2 communicates with a metering chamber 4 having a reduced section. The piston 3 has a part with reduced diameter 5 that engages in a fluid-tight manner inside the metering chamber 4, by means of a cap or seal ring made of plastic material (such as PTFE or nylon) fitted to the part of the piston 5. The seal means or gasket can be formed in one piece with the part with reduced diameter 5 of the piston, for example in the form of cap, rib or enlarged rim. A precharged compression spring 6 is located in the cylinder 2, between the enlarged head of the piston 3 and a wall of the opposite end of the cylinder 2. An actuation rod 31 is connected to the piston 3, passes through the spring 6 and through a passage 34 in the body 1, to exit from the body 1. At one end or close to one end of the rod 31 a handle 32 is provided to move the rod 31 and the piston 3. If desired, the end of the rod 31 can be connected to a mechanism, such as a lever mechanism, so that the user can easily actuate the device in opposition to the compression force of the spring 6. A bolt device 33 provided on the body engages with the rod 31 to block the rod 31 in a charged position, according to the illustration in Fig. 1.
An actuation or release button 35 is provided to release the bolt device 33.
Moreover, a cavity 15 is defined inside the body 1 in which a collapsible bag 10 or a replaceable reservoir containing the methacholine solution or suspension is located. A door 16 on the side of the body 1 can be opened to change the collapsible bag 10 or the reservoir. By means of a connector 12, the inside of the bag 10 communicates with an inlet passage, which in turn communicates with the chamber 4 via a non-return valve 13.
Moreover, the chamber 4 is connected to an outlet passage 21 that extends from the chamber 4 to an atomizing head 22, via a non-return valve 23 and a pressure release valve 25.
If desired, the body 1 can be provided with a mouthpiece 40, which creates an atomizing chamber around the atomizing head 22.
In use of the device of Fig. 1, when the piston 3 is in the charged position as illustrated in Fig. 1, the metering chamber 4 is full of fluid delivered from the bag 10, via the passage 11 and the non-return valve 13. The compression spring 6, as mentioned above, is already precharged when it is mounted in the cylinder 2. Charging of the spring is further increased by pulling back the rod 31 and consequently the piston 3 to the charged position illustrated in Fig. 1. The rod 31 is blocked in its charged position as illustrated in Fig. 1, by the bolt device 33. Pressing the actuation button 35, the bolt device 33 is released, thus allowing the piston 3 to move suddenly forward under the effect of the compression spring 6, to impart a sudden pressure impulse to the fluid in the chamber 4.
Consequently, the pressure of the fluid in the chamber 4 develops rapidly so as to exceed the limit value of the pressure release valve 25, and the fluid is then ejected under a high pressure through the outlet passage 21 to the atomizing head 22, through the non-return valve 23. During the forward stroke of the piston 3, the non-return valve 13 prevents the fluid from returning into the bag 10, through the inlet passage 11. As the fluid is ejected through the atomizing head 22, it is atomized in a fine mist, which can thus be inhaled. The optional mouthpiece 40 provides an atomizing chamber inside which the fine mist is enclosed, facilitating the inhalation thereof.
To recharge the device, the rod 31 is drawn back by means of the handle 32 in opposition to the elastic force of the spring 6. At the end of its stroke, the bolt 33 automatically blocks the rod 31 in a locked end position. During this movement of the piston 3, the fluid is drawn from the collapsible bag 10 into the pressurized chamber 4, through the inlet passage 11 and the non-return valve 13. At this point, the non-return valve 23 prevents air from being drawn into the pressurized chamber 4 through the outlet passage 21. Due to blocking of the rod 31, the fluid in the pressurized chamber 4 is maintained at ambient pressure and there is little or no risk of loss of fluid from the chamber. Actuation of the bolt device 33 provides the user with a clear indication of when the piston 3 has completed the desired movement inside the cylinder 2 and the required dose of fluid has been received. If the user does not draw back the rod 31 sufficiently, the bolt device 33 will not engage and the user will detect the elastic force to the spring 6 and will know that the rod 31 must be drawn back further. Consequently, the bolt device 33 provides both means for retaining fluid in the chamber 4 at ambient pressure, and means for warning the user of the incomplete actuation of the device, thereby reducing the risk of variable actuation of the device.
Consequently, the delivery device is once again in a charged position, as illustrated in Fig. 1, ready to be actuated.
It must be understood that, in the use of the delivery device illustrated in Fig. 1, a metered dose of fluid product is pressurized and atomized in an extremely precise and repeatable way. When the rod 31 and the piston 3 are drawn back into the charged position, a metered amount of fluid product will be drawn into the pressurized chamber 4. Releasing the bolt device 33, the piston 3 will be urged forward so as to impart a predetermined amount of energy, and consequently increase its pressure to a predetermined extent. Consequently, as the pressurized fluid is ejected through the atomizing head 22 having predetermined atomizing properties, the fluid will be atomized in a fine mist having a predetermined average size of the droplets, without the use of a propellant or of other liquefied gases.
To atomize the fluid in a very fine mist, for example having an average size of the droplets from 1 to 12 μιη, a very high pressure must be applied to the fluid in the chamber 4. By way of example, the capacity of the chamber 4 can be 20 microliters; and the diameter of the small end 5 of the piston 3 can be 2 mm; the diameter of the cylinder 2 can be 15 mm, the force of the spring 6 can be 100 newtons, and the atomizing head 22 can have an outlet orifice with a diameter from 3 to 15 μιη. In a similar arrangement, a pressure of the order of 4 x 107 P (400) bar can be generated in the fluid in the chamber 4. The cavity 15 can be in communication with the atmosphere and can be at atmospheric pressure. In an alternative embodiment, the cavity 15 can be pressurized to above atmospheric pressure, which contributes to forcing the content of the collapsible bag 10 to enter the chamber 4 without the need to create subatmospheric pressures in the chamber 4. This can contribute to avoiding the formation of gas bubbles in the fluid sucked into the chamber 4. The pressure release valve 25 and the non-return valve 23 can be combined as a single assembly. A practical embodiment can have a different structure; for example, a lever mechanism or other gear mechanism can be used to facilitate charging of the piston 3 in opposition to the spring 6. In an example, the delivery device can be provided with a cover, which when opened, automatically charges the piston 3 and blocks the bolt device 33, so that the delivery device is ready to operate. The delivery device could be operated by actuating the button 35, when the cover is opened. In an alternative arrangement, the piston 3 can be charged in opposition to the spring 6 and the bolt device 33 can be blocked, while a cover of the delivery device is closed. Consequently, the device is precharged and can be operated immediately after opening of the cover. In another variant, opening of a cover of the device can automatically charge the piston 3 in opposition with the spring 6, block the bolt device 33, and then automatically release the bolt device 33 at the end of the opening action of the cover, so that blocking is only transitory.
The delivery device of Fig. 1 preferably has small dimensions. As, unlike known delivery devices, it does not require to provide a large volume to contain a pressurized liquefied gaseous propellant, it can be easily produced in small dimensions.
Nonetheless, the container of the product, in the form of collapsible bag 10, can contain a much larger amount of drug compared to conventional delivery devices. For example, while conventional delivery devices could be limited to 200-400 doses, a delivery device constructed according to the lines illustrated in Fig. 1 can easily contain 1000 or more doses, in the collapsible bag 10. It is also understood that the content of the bag 10 is protected from atmospheric pollution and actuation of the device takes place by atomizing the fluid in the chamber 4 without the use of a jet of air, and therefore the device operates as an airless spray device.
When the bag 10 is empty, it can simply be removed from the cavity 15 and replaced with a new bag. The bag 10 preferably comprises a gasket to prevent product from escaping from the bag 10, unless the bag 10 is connected to a connector, such as 12. In alternative embodiments, a part of the piston or valve system can be disposable, together with the product receptacle such as the collapsible bag 10. It must be understood that, in use of the delivery device illustrated, there is nothing that stops discharge of the content of the chamber 4 in the form of atomized fluid, once the actuation button 35 has been pressed to disengage the bolt device 33 and consequently to disengage the spring 6. Consequently, the amount of energy applied by the spring 6 to the metered amount of fluid in the pressurized chamber 4 is determined in an absolute manner, so that the increase in pressure to which the metered amount of fluid is subjected is also predetermined in an absolute manner. This objective can be achieved in all the other embodiments described below.
Another feature of the delivery device of Fig. 1 is that the metered amount of fluid in the chamber 4 is subjected to an increase in pressure only when the actuation button 35 has been pressed to disengage the bolt device 33 and consequently disengage the spring 6. This offers the advantage that no gasket or other means are required to condition the highly pressurize fluid, before the atomizing stroke. The increase in pressure applied by the spring 6 and by the piston 3 to the metered amount of fluid in the chamber 4 causes the pressurized fluid to pass through the atomizing head 22, to be atomized thereby. This objective is achieved in all the other illustrated embodiments of the invention described below.
Another important advantage of the delivery device of Fig. 1 is that, by pressing the actuation button 35 to disengage the bolt device 33 and the spring 6, the atomizing head 22 does not move inside the body 1, but only the button 35 moves. This makes it easier to direct the atomized fluid precisely, and is in contrast to a conventional vertical axis finger-operated pump system, in which the atomizing nozzle is depressed to trigger atomizing. This would be disadvantageous in an inhaler for medical use, as it would be difficult to direct the atomized fluid precisely.
In the embodiment of Fig. 1, the stroke of the piston 3 is fixed; if desired, means can be provided to vary the stroke of the piston. These means are preferably calibrated, so that the user can adjust the delivery device as required to deliver different amounts of atomized fluid. Once the adjustment means have been set to a specific value, the MDI will then provide a metered dose of mist in a highly repeatable manner, exactly as if the stroke of the piston were fixed.
The device of Fig. 1 has been described in terms of a device in which the cylinder of the pump mechanism is static and the piston moves axially therein. However, it is possible for the cylinder to be carried on the rod 31 and the piston to be fixed.
In the embodiment illustrated in Fig. 2, a fluid product 50 is contained in a collapsible tube 51 that is formed in one piece with an extended nozzle 52 that acts as a piston. The nozzle/piston 52 is positioned so as to perform a back-and-forth motion inside a cylinder 53. A simple nonreturn valve 54 is incorporated at the end of the nozzle/piston 52. A metering chamber 55 is defined at the end of the cylinder 53, and communicates via a simple non-return valve 56 with an atomizing head 57.
The cylinder 53, the non-return valve 56 and the atomizing head 57 are all contained in a casing 58, which is formed with annular ribs 59, which serve to position the casing 58 in a first part of main body 60.
The upper part of the tube 51 is formed with an annular rib 61, which serves to position the tube 51 in a second part of main body 62. An elastic force device is provided to urge the two parts of main body 60 and 62 toward each other. A bolt device is provided to block the two parts of main body 60, 62 at a predetermined distance from each other, in a charged condition, and an actuation device is provided to release the bolt device.
The embodiment of Fig. 2 functions as follows. The delivery device is in an uncharged or "ready for use" condition. By means of an appropriate charging mechanism, such as a lever mechanism, the parts of main body 60 and 62 are moved away from each other so that the nozzle/piston 52 is drawn back with respect to the cylinder 53. In this way, the depressurization in the chamber 55 causes the fluid product 50 to be drawn from the tube 51, via the non-return valve 54, to fill the chamber 55. During this action, the non-return valve 56 serves to prevent air from entering the chamber 55 from the atomizing assembly 57.
At the end of the charging stroke, the bolt device operates in the sense of keeping the parts of main body 60, 62 at a distance from each other in predetermined relative positions. Releasing the bolt device via the actuation device, due to the force device the nozzle/piston 52 is urged suddenly to enter the cylinder 53 to apply a sudden pressure to the fluid product 50 in the chamber 55, in a generally similar manner to that described in the embodiment of Fig. 1. The pressurized fluid product is then ejected under pressure into the atomizing assembly 57, via the non-return valve 56, and is then atomized by the atomizing assembly 57 to provide a fine mist.
The MDI is then recharged by the charging mechanism to move the two parts of main body 60, 62 away from each other once again in opposition to the force of the elastic force device. It is thus understood that the embodiment of Fig. 2 operates in a generally similar manner to that of the embodiment of Fig. 1. However, in Fig. 2 the product 50 is provided with the tube 51 which, together with the piston nozzle 52 and with the simple non-return valve 54, can be changed as a complete disposable assembly. The tube 51 for the product and its integral nozzle 52 and the non-return valve 54 can be made easily and relatively inexpensively of plastic materials. The user is protected from contact with the fluid product 50, unless the delivery device is not actuated correctly.
Characteristics of the embodiments of Fig. 1, including variants that have been described above, can be provided where appropriate in combination with the characteristics of the embodiment of Fig. 2.
In the embodiment of Fig. 2, one or other of the parts 60, 62 can be fixed in relation to a main body of the delivery device, the other of the parts 60 and 62 thus being movable with respect to the fixed part. Alternatively, both the parts 60 and 62 can be movable with respect to a main body of the delivery device.
Fig. 3 shows, in an enlarged detail, an example of an atomizing head assembly 80. An inlet passage 81 formed in a body 82 leads to an inlet chamber 83. A filter 84 is interposed between successive sections of the inlet chamber 83. The final section of the inlet chamber 83 leads to a whirling chamber 85, which in turn leads to a nozzle 86.
The object of the filter 84 is to prevent the particles from blocking the final orifice. For example, the filter 84 can be made of stainless steel mesh, having a mesh size ranging from 1 to 10 μιη, preferably 3 μιη.
Using a final atomizing orifice of the order of 6 μιη associated with a high pressure applied to the fluid to be atomized (via the store of energy such as that of the compression spring 6), a very effective and uniform average size of the droplets of the final atomized fluid is obtained. Tests with an outlet orifice of the order of the 6 μιη associated with a pressure of the fluid of the order of 3 x 107 P (300 bar), produced a uniform atomized fluid with an average size of the droplets of around 5-8 μιη. The diameter of the outlet orifice is preferably less than 100 μιη.
The diameter of the droplets preferably ranges from 1 to 20 μιη, and more preferably from 3 to 10 μιη.
Although it is preferable to use an orifice with a nozzle of small size to obtain atomizing of the fluid, it is also possible to use alternative atomizing means. For example, as shown in Fig.
4, a jet of fluid 102 can be produced through an outlet orifice 104 by high speed impact on an object such as a metal sphere 106, which can cause atomizing of the fluid.
Another alternative configuration is shown in Fig. 8, where two high speed and high pressure jets of fluid 110 are brought together, so that the fluid is atomized in the point in which they meet.
EXAMPLES
A series of examples aimed at verifying the validity of the delivery device present in the kit according to the invention, for performing the challenge test with methacholine, are illustrated below.
The examples have been conducted comparing the delivery characteristics of the device described previously with the delivery characteristics of common dispensers for inhalation use.
The object of the examples is to characterize with measurable physical parameters the differences between the common dispensers and the dispenser described in the present description from the point of view of emission of the active compound.
The characteristics that contribute to defining the inhalation delivery device as "ideal" are numerous. In particular, the following can be indicated:
Effectiveness, for permitting inhalation of a sufficient amount of respirable active substance with particles < 6 μιη; effectiveness must be independent of the airflow generated by the patient.
Reproducibility, i.e. the capacity to deliver doses always with the same amount and respirable fraction.
Precision, which permits knowing when the drug is about to finish and that inhalation has been effectively implemented.
Stability, i.e. the fact that the inhalation composition present inside it remains unchanged over a long period of time.
Ease of use, i.e. the device must be easy to use even in critical phases, must be pocket sized, light and easy to transport, and also must be multidose, i.e. it must allow the delivery of numerous doses of the composition contained therein.
The aforesaid characteristics are a function of the constructional characteristics of the single dispensers. These can differ greatly based on the type of dispenser considered, and can condition, even significantly, the effect of the inhalatory response. In fact, the difficulty and limits encountered by the patient in performing effective inhalation are based on these possible differences in delivery effectiveness.
Among the delivery systems for inhalation drugs, devices of the MDI (Metered Dose Inhaler) type, of which there are numerous types on the inhaler market, still occupy a leading position. However, regardless of the aesthetic and constructional differences between the individual dispensers, MDIs all have some common strengths and weaknesses. The main problems of these dispensers are linked to the fact that they are highly dependent on the cognitive capacity and on the physical ability of the patient, as in order to perform delivery/inhalation, perfect coordination by the patient is required. In fact, the patient must, in sequence, start actuation of the spray from the dispenser and simultaneously breathe deeply to inhale the active substance. The time available between these two actions varies from 290 to 400 msec. The time available is so limited that, in most cases, it is difficult for the majority of patients (even those in perfect physical and cognitive conditions) to make the best use of it. This critical point leads to poor aerosol performance and high bioavailability of the active substance, with over 80% of the dose delivered being in fact absorbed by the oropharyngeal mucosa and swallowed, resulting in poor response and high frequency of side effects.
All this transforms into reduced lung deposition, and into a substantial variability of the inhaled dose, and therefore into reduced effectiveness and efficiency of the treatment.
Three different types of MDI were used and compared to a dispenser according to the present description.
The three MDI dispensers used for comparison were three dispensers marketed with the brands Aliflus®, Flutiformo® and Ventolin®.
For each type of dispenser, 2 specimens of dispenser coming from two different manufacturing batches were used.
For each dispenser, 2 deliveries in sequence were measured, with the canister full (90% or 100%)). The results set down below are the results obtained for each delivery.
The parameters evaluated were:
Absolute speed (in meters/second) at 5-10-20 cm from the dispenser, from the start of the jet; Materials used:
- High speed video cameras (300 - 1200 frames per second);
- Specific video analysis software capable of detecting: speed, area, distance and turbulence of the jet. (BIOMOVIE Software);
- 'Dark Chamber' controlled environment, with light designed to optimize and maximize the contrast of the jet and with no turbulence caused by convective motion. Pressure: standard at 800 meters above sea level. Temperature: around 18 degrees.
- Electromechanical actuator of the dispenser to ensure uniformity and
comparability in the tests.
Tables 1 and 2 below illustrate the data relating to the dispenser of to the kit according to the present invention.
Tables 3, 4, 5, 6, 7 and 8 illustrate the data of the MDI dispensers for comparison.
Object: Proving the effectiveness of one dispenser compared to others, highlighting effectiveness between the dose delivered and the lung deposition of the substance delivered. Table 1
Figure imgf000020_0001
Table 2
Figure imgf000020_0002
Table 3
Figure imgf000020_0003
Table 4
Figure imgf000021_0001
Table 7
Figure imgf000022_0001
RESULTS
From the analysis performed on the kinetics of the different dispensers tested and from the data obtained shown in the tables, it can be seen how with a dispenser of the kit according to the present invention better results are achieved compared to other inhalers currently on the market. In particular, an amount of drug with particles < 6μιη is inhaled, regardless of the airflow generated by the patient, and doses always with the same amount and respirable fraction are delivered. Moreover, with a kit to perform the bronchial challenge test with methacholine according to the present invention, precise and stable tests are obtained in which it can be observed that the flow remains unchanged over a long period of time. Finally, the kit to perform the bronchial challenge test with methacholine according to the present invention is easy to use, pocket-sized, light and multi-dose.

Claims

Kit comprising:
• a device for delivering a metered amount of an atomized fluid obtained by dispensing an amount of pressurized liquid through atomizing means (22, 57, 80), wherein the device comprises: a chamber (4, 55, 75) for containing the metered amount of a fluid; a replaceable or collapsible fluid reservoir (10; 16; 51) from which said chamber (4, 55) can be charged with fluid; a spring (6) for retaining a predetermined amount of energy and applying it via a piston (3, 52) to the metered amount of fluid in the chamber (4, 55, 75) so as to subject a metered amount of fluid to a predetermined increase in pressure from a lower pressure to a higher pressure of 5 x 106 Pa (50 bar) or more, preferably of 107 Pa (100 bar) so as to permit delivery of said metered amount of fluid from said chamber (4, 55, 75) at said higher pressure; atomizing means (22, 57, 80) for atomizing the fluid delivered from said chamber (4, 55, 75);
• a methacholine solution or suspension in a concentration from 0.01 mg/ml to 200 mg/ml.
Kit according to claim 1, wherein said atomizing means (80) comprises an outlet aperture (90; 104) having a hydraulic diameter from 1 to 100 μιη preferably 1 to 50 μιη. Kit according to one or more of preceding claims, wherein said device is provided with means (33) to retain said spring (6) in a state retaining said predetermined amount of energy, and actuation means (35) for releasing said predetermined amount of energy from said spring (6).
Kit according to one or more of preceding claims, wherein the piston (3, 52) acted on by said spring (6) is part of a pump mechanism (3, 4, 13, 23; 52, 55, 54, 56) and said chamber (4; 55) is provided as the cylinder space in the pump mechanism beyond the pump piston (3; 52).
Kit according to claim 4, wherein the pump mechanism (3, 4, 13, 23) is provided with a mechanism (33) whereby the pump can be held in the cocked state prior to release of the energy from the spring (6).
Kit according to one or more of the preceding claims, wherein the piston (52) is hollow and provides a channel for fluid to enter the chamber (55).
Kit according to claim 6, wherein the channel is provided with non-return inlet valve means (54) for the chamber (55).
Kit according to one or more of the preceding claims, wherein said chamber is a variable volume chamber (4; 55; 75) with non-return inlet valve means (13; 54; 74) and non-return outlet valve means (23; 56; 76) to permit repeated charge of fluid into said chamber (4; 55; 75) and discharge of fluid from said chamber (4; 55; 75).
Kit according to one or more of the preceding claims, wherein said atomizing means (22; 57; 80) comprises an outlet aperture (104) arranged to form a jet of the fluid (102) and an impingement body (106) which is located in the line of trajectory of the jet of fluid (102) and which is arranged to cause breakup of the jet of fluid (102) into a spray of droplets.
Device for delivering a metered amount of an atomized fluid obtained by dispensing an amount of pressurized liquid through atomizing means (22, 57, 80), wherein the device comprises: a chamber (4, 55, 75) for containing the metered amount of a fluid; a replaceable or collapsible fluid reservoir (10; 16; 51) from which said chamber (4, 55) can be charged with fluid; a spring (6) for retaining a predetermined amount of energy and applying it via a piston (3, 52) to the metered amount of fluid in the chamber (4, 55, 75) so as to subject a metered amount of fluid to a predetermined increase in pressure from a lower pressure to a higher pressure of 5 x 106 Pa (50 bar) or more, so as to permit delivery of said metered amount of fluid from said chamber (4, 55, 75) at said higher pressure; atomizing means (22, 57, 80) for atomizing the fluid delivered from said chamber (4, 55, 75); characterized in that said reservoir contains a methacholine solution or suspension in a concentration from 0.01 mg/ml to 200 mg/ml.
PCT/EP2016/060901 2015-05-14 2016-05-13 Kit for performing a bronchial challenge test with methacholine and device containing methacholine WO2016180975A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109621105A (en) * 2018-05-11 2019-04-16 董连鹏 A kind of Respiratory Medicine nasal spray cleaning device

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5497944A (en) * 1990-03-21 1996-03-12 Dmw (Technology) Limited Atomising devices and methods
WO2001097887A1 (en) * 2000-06-19 2001-12-27 Innovata Biomed Limited Delivery of bronchially provocative agents

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5497944A (en) * 1990-03-21 1996-03-12 Dmw (Technology) Limited Atomising devices and methods
WO2001097887A1 (en) * 2000-06-19 2001-12-27 Innovata Biomed Limited Delivery of bronchially provocative agents

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
METHAPHARM INC.: "POWDER FOR INHALATION NOT FOR INJECTION A BRONCHOCONSTRICTOR AGENT FOR EXPERIENCE BRONCHOCONSTRICTION AT A DOSAGE AS LOW AS 0.025 MG/ML OR VERY LOW BASELINE PULMONARY", 1 January 2008 (2008-01-01), 81 Sinclair Boulevard Brantford, Ontario, Canada N3S 7X6, pages 1 - 2, XP055238533, Retrieved from the Internet <URL:http://www.accessdata.fda.gov/drugsatfda_docs/label/2008/019193s013lbl.pdf> [retrieved on 20160104] *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109621105A (en) * 2018-05-11 2019-04-16 董连鹏 A kind of Respiratory Medicine nasal spray cleaning device

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