IE850714L - Dosage device. - Google Patents

Abstract

A dosage device for dosing with high accuracy a particulate material containing a pharmacalogically active substance, including a storage chamber (4), a rotatable dosing unit (2) adjacent the storage chamber, an operating unit (1) to cause relative rotation between the dosing unit and the storage chamber, the dosing unit (2) being provided with a plurality of upwardly opening recesses (7) opening into said storage chamber (4), to receive particulate material therefrom. Scrapers (8) are positioned immediately above these recesses to pack and level the particulate material into the recesses (7) and level the material off with the upper surfaces of the recesses as the dosing unit rotates relative to the storage chamber (4) The operating unit (1) causes an indexing of the dosing unit (2) between discrete rotational positions in one of which one of the recesses (7) is in direct communication with a generally 9 upwardly extending dispensing channel (5) so that when the unit is turned upside down that recess will discharge through the channel (5). <IMAGE> [SE8401796D0]

Description

2 The present invention relates to a new dosage device intended to bo used for dosing of micronized or granulated substances or microcapsules (hereinafter referred to collectively as particulate material) ana 5 containing pnarmacologically active substances.

Several preparations of drugs are nowadays administered in micronized or granulated form or in the form of microcapsules. These substances are filled into capsules of hard gelatine, which are intended for oral 10 administration and are swallowed whole by the patient. Children and adults who have difficulties in swallowing a wnole capsule are recommended to open the capsule and spread the contents on a suitable piece of food and to swallow. It is, however, difficult to open the capsule 15 and pour out the contents without any loss of the substance. Capsules of hard gelatine are an expensive, but effective, way to administer pharmacologically active substances to patients, who are able to swallow the capsules unbroKen. It is, nowever, not sensible to use this kO expensive way of dispensing into capsules of nard gelatine, wnen the patient later on, with some difficulty, opens tne capsule and pours out the contents.

It has previously been proposed to provide dosage devices to enable the particulate material to be 25 dispensed accurately. For example DE-A-2 05i: 051 describes a dosage device comprising a control unit and a storage chamber. The control unit is fitted relatively loosely to the casing of the device. Substances having small particles trius easily fall on the sliding surfaces between the two relatively movable units, so that substance being fed jams. With such a dosage device, it is difficult to dose small amounts of micronized or granulated substances witn an accuracy whicn is sufficient for the dispensing of drugs. 30 3 According to the present invention there is provided a dosage device for dosing with high accuracy a particulate material containing a pharmacalogically (active substance, said device comprising e storage chamber, b a rotatable dosing unit adjacent said storage chamber, an operating unit to cause relative rotation between said dosing unit end said storage chamber, a plurality of upwardly opening recesses in saia dosing unit, at least one of which opens into said storage chamber, to 10 receive particulate material tnerefrom, scrapers positioned to pacK and level the particulate material into the recesses and level it off with the upper surface of the dosing uni-fc as tne dosing unit rotates relative to the storage chamber, operating means on said operating unit 13 for causing indexing of the dosing unit between discrete rotational positions, and a generally upwardly extending dispensing channel positioned at one of said discrete positions to communicate with one of said recesses, so tnat saia one recess may be emptied by turning said device 20 upside down.

Kith the construction according to the present invention, the substance is prevented from getting into contact with the sliding surfaces in tne two relatively movable parts of the dosage device and in this way feeding 25 of sach dose can be acnieved without any problems. In tne dosage device according to the invention, the scrapers make it possible to fill tne recesses in the dosing unit in a accurately reproducable way. A high dosage accuracy can thus be obtained by the rotation of the dosing unit. 30 in order that the invention may snore readily be understood, the following description.is given, merely by way of example, reference being made to the accompanying drawings, in which:- Figure 1 is en axial cross-section el one embooi-35 sient of dosage eevice according to the invention; and Figure 2 is a cross-section taken along tne line 21-21 of Figure 1.

Tfte dosage unit of tns present invention can be considered so comprise four separate units &s Zollo&s:- 4 an operating unit 1 at the bottom of the dosage device; a spring loaded dispensing unit 2; a scraping unit 3; and 5 a storage chamber 4 provided with a dispensing channel 5 for the dose to be dispensed.

A further separate part is shown in the drawings and is preferred, but is not essential, this being in the form of a plastic or metal hood 6 wnich can be retained 10 by a peripheral rib (not shown)at the upper part of the i operating unit 1. This rib enables the hood to be removably retained. An alternative way of sealing the device is to provide a plug in the top of the dispensing cnannel 5. 1 5 At. tne lower mid part of tne storage chamber t, tne scraping unit 3 is fixed to tne inner wall of the r-: orage chamber so that it cannot rotate relative thereto. Tne scraping unit in fact includes the lower part of tne dispensing channel 5 which is formed integrally with 20 the storage chamber 4. From Figure 2 it will be seen more clearly tnat the scraping unit 3 includes 5 radially extending arms each of wnich carries a resilient scraper 8 in sliding contact with the upper surface of the dosing unit 2 which, in turn, is provided witn six 25 circumferentially spaced sliyhtly frustoconical recesses 7 positioned immediately under the scrapers 8. In order to guide for rotation che dosing unit 2, tne scraping unit has an outer peripheral skirt engaging tne cylindrical outer surface of tne dosing unit 2 and a 30 short inner annulus engaging the upper surface of the dosing unit inwardly of the recesses 7 in order to prevent jamming at feeding. Tne dosing unit 2 is loaded by a spring 9 in order to press tne dosing unit " against the scraping unit. Between the dispensing 35 unit and the spring there is situated a disc 14 which is keyed to the storage chamber dosing unit and has a toothed ring 13.

The operating unit 1, against which the other end of the spring 9 abuts, carries a resilient arm 12 wnich is 5 engageable with the toothed ring 13. Thus the disc 14, in effect, controls the angular movement of the dosing unit 2 so that one of the recesses 7 will always stop in the correct position that is immediately below the 5 dispensing channel 5 as shown in Figure 1. Furthermore, the disc 14 reduces the friction between the spring and ^ the dosing unit.

In the operating unit 1 there is provided a space 10, as illustrated closed by a porous pad and into t 10 the space 10 can be inserted a drying agent sucn as silica gel in order to protect the contents of the device from the humidity of tne air. The ingress of humidity will also be reduced by the provision of the hooa 6.

The particulate pharmaceutical^ active substance is stored inside the storage chamber 4 ana the actual dosing operation is carried out with the dosing device in the upright position shown in Figure 1, by rotating the operating unit at first counterclockwise and then clockwise. The ratcnet mechanism formed by the tootned 20 ring 13 and the resilient arm 12 will thus index tne dosing unit so that first one and then another recess appear immediately under the dispensing channel. All of the recesses, however open into the storage chamber and can be filled with tne particulate material therein.

Thus, a predetermined amount of particulate pharmaceutical^-active substance can be dosed by tne correct choice of the size of the recess 7. The effect of the scrapers 8 on the scraping unit 3, past which the dosing unit recesses move,is firstly co force and pack the particulate 30 material into cne recess and secondly accurately to level off the particulate material at the top of the recess.

Tnis means that when a recess 7 arrives immediately below 11 tne dispensing channel 5 it will be completely ana accurately full.

, All that is then necessary is to turn the dosage >> device upside down and tne particulate material will flow down the dispensing channel 5. By cnoosing the size of the recess for whichever substance is to be dispensed, 6 one can thus choose the size of a dose which may, for example be varied within wide limits, say from 1 to 5 mg or 5 to 200 mg. The number of recesses in the dosing unit may vary depending on different factors, such as 5 the amount of active substance which snould be administered in each dose, tne physical properties of the active substances and so on. In a preferred embodiment, the dosing unit has six recesses and these recesses are preferably cylindrical or preferably frustoconical as shown and 10 should preferably hold 1 dose of active substance.

The size of the storage chamber may be chosen to suit the reqirements expected for a particular active substance. In a dosage device where the storage chamber cannot be refilled with active substance, the chamber may, ^ for example,contain sufficient active substance for about 100 doses.

In an alternative embodiment the dosage device nas a resilient key which makes it possible to feed the device witn one hand. Each push on the key causes 20 indexing of the dosing device so that a recess filled with the active substance is placed in communication witn the dispensing channel.

The dosage device may be used as container and aid in dispensing of a great number of active substances such as enprophylline, theophylline and terbutaline.

Example In order to demostrate tne dosage accuracy of the dosage device according to the present invention the following tests have been carried out with different 30 sizes of the recesses 7. The container was filled with Theo-Dur sprinkle substance (which is a slow release preparation of theophylline) mixed with 1 and 2% of talcum respectively. When the dosage accuracy of 500 doses was established a maximum deviation of 3.5% was obtained. 35 Cf. the table below. 7 Test with seven different dosage devices containing Theo-Dur sprinkle substance mixed with talcum The figures below are the average values of 500 doses from eacn dosage device. j Dosage Talcum device 1 % 2% mg/dose srel % mg/dose s ■, rel % 1 104. 1 2.15 2.1 104.2 2.45 2.4 2 94.0 2.36 2.5 94.0 2.66 2.8 3 85.4 2.29 2.7 84.8 2.30 2.7 4 73,2 2.45 3.3 75.1 1.73 2.3 5 64.7 1 .68 2.6 64.5 2.02 3.1 6 54.3 1 .33 2.5 53.4 1 .87 3.5 7 45.8 1 .34 2.9 45.9 1 .30 2.8 As a comparison reference is made to Pnarm. Nord, which specifies that 90% of the capsules shall have a weight which does not deviate more than 10% from the stipulated weight. The rest shall not deviate more 20 than 20%. With tne new dosage device according to the invention these requirements are thus met with an ample margin. p

Claims (1)

1. CLAIMS: 1. A dosage device for dosing with high accuracy a particulate material containing a pharmacalogically active substance, said device comprising a storage chamber, a rotatable dosing unit adjacent said 5 storage chamber, an operating unit to cause relative rotation between said dosing unit and said storage chamber, a plurality of upwardly opening recesses in said dosing • unit, at least one of which opens into said storage chamber, to receive particulate material therefrom, 10 scrapers positioned to pack and level tne particulate ' material into the recesses and level it off with the upper surfaces of the recesses as tne dosing unit rotates relative to the storage chamber, operating means on said operating unit for causing indexing of the dosing 15 unit between discrete rotational positions, and a generally upwardly extending dispensing channel positioned at one of said discrete positions to communicate with one of said recesses, so that said one recess may be emptied by turning said device upside down. 20 2. A device according to claim 1 wherein the operating unit is itself rotatable relative to the storage chamber to effect indexing of the dosing unit. 3. A device according to claim 2, wherein the operating unit can be rotated alternately clockwise and 25 counterclockwise about the axis of rotation of the dosing unit and wherein said operating means comprise a ratchet mechanism between the operating unit and tne dosing unit, wnereby the alternate clockwise and counterclockwise rotation of the operating unit will cause indexing of the 30 dosing unit in only one rotational sense. 4. A device according to claim 3, wherein said ratchet mechanism comprisea a resilient arm on the operating unit which engages on annularly spaced teeth on the dosing unit. 35 5. A device according to any preceding claim, } wherein said operating unit is mounted below said dosing unit. 6. A device according to claim 5, when appendent to claim 4, wherein a disc which is keyed to the storage chamber is urged against said dosing unit by a spring engaged between saia disc and said operating claim, wherein the dispensing channel passes through the storage chamber. 8. A device according to any preceding 10claim, wherein the storage chamber has a closable inlet by means of which the storage chamber can be refilled. 9. A device according to any preceding claim, wherein the dosing unit is provided with six circumferentially spaced recesses. 15 10. A device according to any preceding claim wherein said recesses are frustoconically shaped, being wider at the open end communicating with the storage chamber. 20 dosing with high accuracy a particulate material oontaihing a pharmacalogically active substance, said device being substantially as hereinbefore described with reference to and as illustrated in, the accompanying drawings. 5 unit. 7. A device according to any preceding 11. A dosage unit according to claim 1 for Dated this th© 20th day of M&srch, 1985 BY 8 EXECUTIVE 27 Clydg Ro®d„ B&IXsbsrid.ge, Dublin A ACKNTS FOR THE APPIjIC&NTS »