NZ211576A

NZ211576A - Dispenser for metered doses:rotating trap chamber

Info

Publication number: NZ211576A
Application number: NZ211576A
Authority: NZ
Inventors: K I L Wetterlin
Original assignee: Draco Ab
Priority date: 1984-04-02
Filing date: 1985-03-26
Publication date: 1987-03-06
Also published as: CH668639A5; FR2561912A1; PT80205B; KR850007554A; NO160129B; NO851146L; FI851302A0; CA1304327C; IT8547873A1; GB2156783B; DE3511817A1; SE459781B; ES541813A0; PT80205A; IT8547873A0; IE56449B1; SE8401796D0; IT1181953B; GB2156783A; NO160129C

Description

<div class="application article clearfix" id="description"> •jf. (-t . § a y Priority Date(s): irt.'. ....... 1 ? 5?<T' Complete Specification Filed: fr.. . Class: (y.e?J... $PJA?/.P.&.... 8&&P.R$?& \ Publication Date: !???. P.O. Journal/ No: .««.«.*« ;P^aMARW85 ;■-1 ;NEW ZEALAND ;Patents Act 1953 ;N.Z.No. ;COMPLETE SPECIFICATION ;"DOSAGE DEVICE" ;We, AKTIEBOLAGET DRACO, of Box 34, S-221 00 Lund, Sweden, a Swedish Company, ;do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement : - ;- 1 - ;211576 ;The present invention relates to a new dosage device intended to be used for dosing of micronized or granulated substances or microcapsules (hereinafter referred to collectively as particulate material) and containing pharmacologically active substances. ;5 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 administration and are swallowed whole by the patient. Children and adults who have difficulties in swallowing a whole capsule are 10 recommended to open the capsule and spread the contents on a suitable piece of food and to swallow. It is, however, difficult to open tha capsule 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 15 are able to swallow the capsules unbroken. It is, however, not sensible to use this expensive way of dispensing into capsules of hard gelatine, when the patient later on, with some difficulty, ;opens the capsule and pours out the contents. ;20 It has previously been proposed to provide dosage devices to enable the particulate material to be dispensed accurately, one example describes a dosage device comprising an operating unit and a storage chamber. The operating unit is fitted relatively loosely to the casing of the device. Substances having small particles 25 thus easily fall on the sliding surfaces between the two relatively movable units, so that substance being fed jams. With such a dosage device, which does not have a feeding under force it is difficult to dose small amounts of micronized or granulated substances with an accuracy which is sufficient for the dispensing of drugs. ;30 ;According to the present invention there is provided a dosage device for dosing with high accuracy a particulate material containing a pharmacologically active substance, said device comprising a storage ;' < c o-'t1 ;2 ' ;211576 ;chamber, a rotatable dosing unit below said 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 5 chamber, to receive particulate material therefrom, a scraping unit with scrapers positioned to pack and level the particulate material into the recesses and level it off with the upper surface of the dosing unit as the dosing unit rotates relative to the storage chamber, operating means on said operating unit for causing indexing of the 10 dosing unit between discrete rotational positons, 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. ;15 ;With the construction according to the present invention, the substance is prevented from getting into contact with the sliding surfaces in the two relatively movable parts of the dosage device and in this way feeding of each dose can be achieved without any problems. 20 In the dosage device according to the invention, the scrapers make it possible to fill the 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. ;25 In order that the invention may more readily be understood, the following description is given, merely by way of example, reference being made to the accompanying drawing, in which: ;Figure 1 is an axial cross-section of one embodiment of dosage device 30 according to the invention; and ;Figure 2 is a cross-section taken along the line II-II of Figure 1. ;35 The dosage device of the present invention, is preferably produced in plastic and can be considered to comprise four separate uni^s as follows: ,/.v. ^ ;- 3 - ;an operating unit 1 at the bottom of the dosage device; ;a spring loaded dosing unit 2; ;a scraping unit 3; and a storage chamber 4 provided with a dispensing channel 5 for 5 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 which can be retained by a peripheral rib (not shown) at the upper part of the 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 channel 5. ;At the lower mid part of the storage chamber 4, the scraping unit 3 is fixed to the inner wall of the storage chamber so that it cannot rotate relative thereto. The scraping unit in fact includes the lower part of the dispensing channel 5 which is formed integrally with the storage chamber 4. From Figure 2 it will be seen more clearly that the scraping unit 3 includes 5 radially extending arms each 20 of which carries a resilient scraperjMn sliding contact with the upper surface of the dosing unit 2 which, in turn, is provided with six circumferentially spaced slightly frustoconical recesses 7 positioned immediately under the scrapers 8. In order to guide for rotation of the dosing unit 2, the scraping unit has an outer peripheral 25 skirt engaging the cylindrical outer surface of the dosing unit ;2 and a short inner annul us engaging the upper surface of the dosing unit inwardly of the recesses 7 in order to prevent jamming at feeding. The dosing unit 2 is loaded by a spring 9 in order to press the dosing unit Against the scraping unit. Between the dosing unit, 30 which has a toothed ring 13, and the spring there is situated a disc 14 which is keyed to the storage chamber. The operating unit 1, against which the other end of the spring 9 abuts, carries a resilient arm 12 which is engageable with the toothed ring 13. Thus the disc 14, in effect, controls the angular movement of the operating 35 unit 1 and the dosing unit 2 so that one of the recesses 7 will always stop in the correct position that is immediately below the dispensing channel 5 as shown in Figure 1. Furthermore, the disc 14 reduces the friction between the spring and the dosing unit. ;- 4 - ;& i V 51 <° ;In the operating unit 1 there is provided a space-10, as illustrated closed by a porous pad and into the space 10 can be inserted a drying agent such as silica gel in order to protect the contents of the device from the humidity of the air. The ingress of humidity will 5 also be reduced by the provision of the hood 6. ;The particulate pharmaceutically active substance is stored inside the storage chamber 4 and 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 clockwise and then counterclockwise. The ratchet mechanism formed by the toothed ring 13 and • the resilient arm 12 will thus index the dosing unit so that first one and then another recess appear immediately under the dispensing channel. All of the recesses passes successively the storage chamber 15 and can be filled with the particulate material therein. Thus, a predetermined amount of particulate pharmaceuticaHy active substance can be dosed by the correct choice of the size of the recess 7. The effect of the scrapers 8 on the scraping unit 3 is firstly to force and pack the particulate material into the recesses and secondly accurately to level off the particulate material at the top of the 20 recesses. This means that when a recess 7 arrives immediately below the dispensing channel 5 it will be completely and accurately filled. ;All that is then necessary is to turn the dosage device upside down and the particulate material will flow down the dispensing channel 25 5. By choosing the size of the recess for which ever substance is to be dispensed, 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 the amount of active substance 30 which should be administered in each dose, the 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 should preferably hold 1 dose of active substance. ;- 5 - ;^ -. /? 5*® .ft J "i o 7 6 The size of the storage chamber may be chosen to suit the requirements expected for a particular active substance. In the dosage device the chamber may, for example, contain sufficient active substance for about 100 doses. The dosage device has an opening for filling ^ or refilling of active substance in the upper part of the storage chamber. The opening is preferably sealed by a plastic plug 11. In an alternative embodiment the dosage device has a resilient key which makes it possible to feed the device with one hand. Each push 10 on the key causes indexing of the dosing device so that a recess filled with the active substance is placed in communication with the dispensing channel. The dosage device may be used as container and aid in dispensing 15 of a great number of active substances such as enprophylline, theophylline and terbutaline. The best mode of carrying out the invention known at present is illustrated in Figure 1. 20 Example In order to demonstrate the dosage accuracy of the dosage device according to the present invention the following tests have been 25 carried out with different dosing units with different sizes of the recesses A-G. The container was filled with Theo-Dur Sprinkle substance (which is a slow release microencapsulated preparation i of theophylline) mixed with 1 and 2% of talcum respectively. When the dosage accuracy of 500 doses was established a maximum deviation 30 of 3.5% was obtained. Cf. the table below. - 6 Test with seven different dosage units containing Theo-Dur Sprinkle substance mixed with talcum The figures below are the average values of 500 doses from each 5 dosage device. 10 15 Dosage Talcum unit 1% 2% mg/dose srel % mg/dose srel % A 104.1 2.15 2.1 104.2 2.45 2.4 B j 94.0 2.36 2.5 94.0 2.66 2.8 C i 85.4 2.29 2.7 84.8 2.30 2.7 D 73.2 | 2.45 3.3 75.1 1.73 2-3 E i 64.7 1.68 2.6 64.5 2.02 3.1 F j 54.3 1.33 2.5 53.4 1.87 3.5 G I 45.8, i 1.34 2.9 45.9 1.30 2.8 20 As a comparison reference is made to Pharm. 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 25 more than 20%. With the new dosage device according to the invention these requirements are thus met with an ample margin. « The matter contained in each of the following claims is to be read as part of the general description of the present invention. - 7 - </div>

Claims

<div class="application article clearfix printTableText" id="claims"> 211576 What we claim is 1. A dosage device for dosing with high accuracy a particulate material containing a pharmacologically active substance, said device comprising a storage chamber, a rotatable dosing unit £elow said storage chamber, and an operating unit to cause relative rotation between said dosing unit and said storage chamber, characterised: in that said dosing unit is provided with a plurality of upwardly opening recesses at least one of which opens into said storage chamber to receive particulate material therefrom; in that scrapers are positioned to pack and level the particulate material into the recesses and level it off with the upper surface of the dosing unit as the dosing unit rotates relative to the storage chamber; in that the operating unit is capable of indexing the dosing unit between discrete rotational positions; and in that a generally upwardly extending dispensing channel is 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.
2. A device according to claim 1 characterised in that 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, characterised in that the operating unit can be rotated alternately clockwise and counterclockwise about the axis of rotation of the dosing unit, and in that a ratchet mechanism is provided between the operating unit and dosing unit, whereby the alternate clockwise and counterclockwise rotation of the operating unit will cause indexing of the dosing unit in only one rotational sense.
4. A device according to claim 3, characterised in that the ratchet mechanism whereby the dosing is effected, comprises a resilient arm on the operating unit which engages with annularly spaced teeth on the dosing unit- 8
5. A device according to any one of the preceding claims, characterised in that said operating unit is mounted below said dosing unit.
6. A device according to claim 5, characterised in that a disc, which is keyed to the storage chamber, is urged against said dosing unit by a spring engaged between said disc and said operating unit.
7. A device according to any one of the preceding claims, characterised in that the dispensing channel passes through the storage chamber.
8. A device according to any one of the preceding claims, characterised in that the storage chamber has a closable inlet by means of which the storage chamber can be refilled.
9. A device according to any one of the preceding claims, characterised in that the dosing unit is provided with six circumferentially spaced recesses.
10. A device according to any one of the preceding claims, characterised in that said recesses are frusto-conically shaped, being wider at their open end communicating with the storage chamber.
11. A device according to claim 1, substantially as described herein with reference to the embodiment illustrated in the accompanying drawings. 2 3 • ■ ,) AKTIEBOLAGET DRACO By Their Attorneys - 9 - </div>