Dose dispenser for substances in powder or granular form

Abstract: The dispenser enables a multiplicity of doses of a substance in powder or granular form contained in a reservoir to be dispensed in succession. To form a dose a shaft must be rotated relative to a part of the dispenser, the shaft having to be substantially vertical while the dose is being formed. Between the shaft and said part of the dispenser there is provided a joint which prevents relative rotation if the shaft is not substantially vertical, or which although allowing relative rotation enables a signal to be emitted which can be sensed by the user. In particular the dispenser can be a multi-dose inhaler for medicaments.

Description: This invention relates to a dispenser for dispensing a multiplicity of doses of a substance in powder or granular form contained in a reservoir forming part of the dispenser, this latter being of the type in which to form a dose a shaft must be rotated relative to a part of the dispenser, the shaft having to be substantially vertical while the dose is being formed. A dispenser of the aforesaid type is described for example in Italian patent application MI96A001448 of the present applicant. Such a dispenser falls within the scope of protection of EP-B-0424970 and in addition is provided with a closure and protection adaptor which has to be removed, or opened, to enable the user to gain access to the individual dose dispensed. The presence of said adaptor is particularly useful if the dispenser is an inhaler for medicaments in powder form, and the individual dose to be administered to the patient is so small that the patient is unable to tell whether the dose has been effectively inhaled or not. In this respect, to be able to inhale the dose the patient has to remove or open the adaptor, this requiring a first part of the actual inhaler unit (ie without the adaptor) to be rotated relative to a second part, this automatically resulting in the formation of a dose of medicament withdrawn from a reservoir. The application or, respectively, the closure of the adaptor restores the initial condition. The accompanying Figures 1 to 5 illustrate, as an example of a dispenser falling within the scope of MI96A001448, a multi-dose inhaler for medicaments in powder form, provided with a removable adaptor. These figures basically reproduce the analogous figures of Italian patent application MI96A001448 (however retaining only the reference numerals of interest herein), and specifically: Figure 1 is a front elevation of said multi-dose inhaler provided with an adaptor, this latter being shown separated from the actual inhaler unit; Figure 2 is a side elevation thereof; Figure 3 is a front elevation thereof but with the adaptor applied; Figure 4 is an exploded perspective view thereof; and Figure 5 is an enlarged vertical section therethrough without the adaptor, taken on the line 5-5 of Figure 1. As can be seen from these figures, the multi-dose inhaler 10 for medicaments in powder form, provided with a removable adaptor 14, comprises a shaft 56 which can rotate (together with the adaptor 14 while this latter is being removed by unscrewing it, or reapplied by screwing it on) relative to the cover 62. In this respect, the upper end or head 70 of the shaft 56 (Figure 5) is received in a recess 68 which does not prevent relative rotation between the cover 62 and the shaft 56. As already stated, removing the adaptor 14 from the actual inhaler unit 12 causes a withdrawal and metering unit (which will not be described in detail herein as it is outside the stated objects) to operate in order to withdraw from the reservoir 48 (Figures 4 and 5) a dose of medicament in powder form and bring it into a position in which, by pressing the cover 62 (which can be moved vertically in the two directions in the manner of a pushbutton by virtue of the helical spring 58) with the fingers, the prepared dose is made to fall into the conduit 30 and deposit on its concave base, from whence it can be removed as a result of the sucking action exerted by the patient through the mouthpiece 24. With reference to the inhaler 10, it has been found that if the inhaler 10 is not maintained substantially vertical while the adaptor 14 is being removed, and if the quantity of powder medicament in the reservoir 48 is small (the powder behaving practically as a liquid), it can happen that the powder does not completely cover that part of the disc 36 (Figures 4 and 5) which closes the base of the reservoir 48, with the risk that the metering hole 38 present in the disc 36 is not completely filled with powder. It follows that the medicament dose formed could be less than that prescribed or in any event not homogeneous. Precisely to avoid this problem, the operating instructions accompanying said inhaler must tell the patient to maintain the inhaler substantially vertical while the adaptor is being removed. There is however the risk that some patients, although having read said instructions, forget to maintain the inhaler vertical, with the result that only small or in any event non-constant doses of medicament are administered to the patient because of the inclination of the inhaler. The object of the present invention is to overcome said drawback of known dispensers of the aforesaid type. This object is attained by the dispenser of the present invention, characterised in that between said shaft and the aforesaid part of the actual dispensing unit relative to which the shaft rotates while the adaptor is being removed or opened (ie while the dose is being formed) there is provided a joint which prevents the shaft from rotating relative to said part if the shaft is not substantially vertical, or a joint which although allowing relative rotation enables a signal to be emitted which can be sensed by the user. In this manner the administration of reduced or unsuitable doses can be prevented. In this respect the user either cannot remove the adaptor or receives a signal (for example the user is warned by a series of clicks that the dose formed may not be as prescribed). The user then has merely to repeat the operation while maintaining the dispenser upright, to complete the prescribed dose for dispensing. The aforesaid joint can for example comprise a recess provided in one end of the shaft and formed from a series of angularly equidistant radial cavities having a common central part, the depth of this recess decreasing in moving radially from its centre to the periphery, a similar recess of identical orientation being provided, coaxially facing the first, in said adjacent part of the actual dispensing unit, between the two recesses there being inserted a ball of diameter not exceeding the maximum depth of each of the two recesses, the sum of the minimum depth of the two recesses not being less than the ball diameter, the minimum depth of each recess being substantially less than the ball diameter. The invention will be more apparent from the following description of a multi-dose inhaler according to the invention. This description makes reference to the further accompanying Figures 6-8, in which: Figure 6 is a perspective view of said shaft taken towards its head; Figure 7 is a perspective view of said cover taken from below; and Figure 8 is a longitudinal section taken along the axis of the shaft and cover, showing the joint between these latter, the inhaler being inclined to the vertical. As can be seen from Figure 6, the head 70' of the shaft 56 comprises a recess indicated overall by 1A (the letter A indicating that the relative reference numeral refers to the shaft). The recess 1A is composed of six angularly equidistant grooves 2A extending radially from a common central region. The overall shape of the recess 1A is similar to that of a daisy. The ribs 2A have a depth which gradually decreases from their common region to the periphery. Within the cover 62 (Figure 7) and bounded by a circular rib 69 there is provided a circular cavity 68', in the base of which there is a recess 1C (the letter C indicating that the relative reference numeral refers to elements of the cover) identical to the recess 1A of the shaft 56. When the inhaler is assembled (Figure 5) the cover must be positioned such that the two daisy recesses 1A and 1C coincide in a matching orientation. Between the two recesses there is inserted a ball 3 (preferably of stainless steel), the diameter of which must not exceed the maximum depth of each recess 1A. As is clear from the aforegoing, when the inhaler 10 is maintained vertical (so that the shaft 56 is also vertical) the ball 3 is in the position shown in Figure 6 and does not project from the head 70' of the shaft 56, so that the shaft 56 and cover 62 can be rotated relative to each other. If instead the inhaler 10 is held inclined (so that the ball 3 is located in the position shown in Figure 8), when the patient attempts to remove the adaptor 14 (which requires relative rotation between the shaft 56 and cover 62) this rotation cannot proceed because of the interference of the ball, provided that the material of construction of the constituent parts of the joint is sufficiently rigid and that these parts are sufficiently robust. Consequently if the patient wishes to remove the adaptor, he is compelled to maintain the inhaler vertical. If however the material is sufficiently elastic, rotation can take place by forcing, but in this case producing a series of clicks (with consequent noise) which warn the patient that the inhaler has not been maintained vertical, so that the dose formed by removal of the adaptor may be not that prescribed but less. In this case the patient can easily remedy the situation by simply repeating the operation, ie by reapplying the adaptor 14 and then again removing it, while maintaining the inhaler vertical. If required, instead of said series of clicks or in addition thereto, a series of light signals could be produced, created for example by an LED powered by electric current produced piezoelectrically. It should be noted that if the mouthpiece 24 and tube 30 are removed from the inhaler 10 or if the tube is upperly open, the inhaler becomes a normal dispenser for successively dispensed doses of any powder or granular substance (for example salt, pepper in powder form or vegetable spices for use in cookery).

Claims: A dispenser for dispensing a multiplicity of doses of a substance in powder or granular form contained in a reservoir forming part of the dispenser, this latter being of the type in which to form a dose a shaft must be rotated relative to a part of the dispenser, the shaft having to be substantially vertical while the dose is being formed, characterised in that between said shaft and the aforesaid part of the actual dispensing unit relative to which the shaft rotates while the adaptor is being removed or opened, ie while the dose is being formed, there is provided a joint which prevents relative rotation between the shaft and said part if the shaft is not substantially vertical, or a joint which although allowing relative rotation enables a signal to be emitted which can be sensed by the user. A dispenser as claimed in claim 1, wherein a closure and protection adaptor is provided which has to be removed, or opened, to enable the user to gain access to the individual dose dispensed. A dispenser as claimed in claim 1, wherein the joint comprises a recess provided in one end of the shaft and formed from a series of angularly equidistant radial cavities having a common central part, the depth of this recess decreasing in moving radially from its centre to the periphery, a similar recess of identical orientation being provided, coaxially facing the first, in said adjacent part of the actual dispensing unit, between the two recesses there being inserted a ball of diameter not exceeding the maximum depth of each of the two recesses, the sum of the minimum depth of the two recesses not being less than the ball diameter, the minimum depth of each recess being substantially less than the ball diameter. A dispenser as claimed in claim 1, wherein the signal produced is an acoustic signal. A dispenser as claimed in claim 1, wherein the signal produced is a light signal. A dispenser as claimed in claim 3, wherein both the recess in the shaft and that in the cover are formed of a material having a certain elastic deformability whereas the ball is of a substantially rigid material, so as not to prevent relative rotation by forcing, but to generate a series of clicks noticeable by the user. A dispenser as claimed in claim 3, wherein both the recess in the shaft and that in the cover are formed of a substantially rigid material, the ball also being of a substantially rigid material, so as to prevent relative rotation if the shaft is not maintained substantially vertical. A dispenser as claimed in claim 5, wherein the joint comprises piezoelectric material which as a result of forced relative rotation produces electric current with which to power at least one LED. A dispenser as claimed in claim 1, characterised by being a multi-dose inhaler for medicaments.

Inventors: MCDERMENT IAIN, MCDERMENT, IAIN
Applicants: MIAT SPA, MIAT S.P.A.
Application year: 1998
Main classification: A61M15
IPC codes: A61J7, A61M15