NZ572736A

NZ572736A - Improvements in delivery devices

Info

Publication number: NZ572736A
Application number: NZ57273608A
Authority: NZ
Inventors: William Ernest Pomroy; Martin John Whitehead; Wayne Frederick Leech
Original assignee: Bomac Research Ltd; William Ernest Pomroy; Martin John Whitehead; Wayne Frederick Leech
Priority date: 2008-11-11
Filing date: 2008-11-11
Publication date: 2010-03-26

Abstract

An end cap for a bolus housing (15) is disclosed. The end cap includes a sealing portion, which comprises a sleeve (1) and a plug (8), that covers the open end of a bolus housing, and a skirt (5) depending from the circumference of the end cap, the skirt being configured such that the sides of the end cap are substantially parallel to the side of the bolus housing and the interior of the end cap substantially contacts the exterior of the bolus housing. In one embodiment, the end cap includes a collar (12) that surrounds a substantial portion of the bolus housing, and the skirt is configured to engage with the collar. A method of manufacturing an end cap for a bolus housing is also disclosed.

Description

<div class="application article clearfix" id="description"> 10056662869* ;PATENTS FORM NO. 5 ;Appln Fee: $250.00 ;James & Wells ref: 129742/47 SA ;PATENTS ACT 1953 COMPLETE SPECIFICATION ;IMPROVEMENTS IN DELIVERY DEVICES ;l/WE Bomac Research Limited, a New Zealand company of 102 Wiri Station Road & Hobill Avenue, Manukau City, Auckland, New Zealand; William Ernest Pomroy, an Australian citizen of 365 Scotts Road, RD 4, Palmerston North, New Zealand; Martin John Whitehead, a United Kingdom citizen of Lower Crooked Yard Farm, Macclesfield Forest, Macclesfield, Cheshire SK11 OND, Great Britain; Wayne Frederick Leech, a New Zealand citizen of 2 Rochas Place, Manukau City, New Zealand hereby declare the invention for which I/We pray that a patent may be granted to me/us, and the method by which it is to be performed to be particularly described in and by the following statement: ;James & Wells Ref: 129742/47 SA ;IMPROVEMENTS IN DELIVERY DEVICES TECHNICAL FIELD ;This invention has application to delivery devices for delivering medicaments to animals. ;5 In particular, the present invention has application to boluses used to treat health conditions in animals. ;BACKGROUND ART ;It is well known in the veterinary field to use boluses to deliver medicaments to ruminants. Boluses can be used to treat specific ailments or as a preventative for 10 specific conditions. ;A bolus is a delivery device for the long term delivery of medicaments to an animal. Typically, the bolus consists of a housing with at least one open end, often made of plastic or metal alloy which contains a series of tablets. ;The housing of the bolus is usually a tubular or cylindrical hollow member. To 15 close the end of the housing, it is common practice to use an end cap to seal off one of the ends of the housing. ;The key function of the end cap is to prevent rumen fluids or other liquids from entering the housing of the bolus. ;The bolus is specifically designed to ensure that the tablets held by the housing is 20 eroded from one direction only. Failure of the end cap will result in erosion of the tablets from both ends of the housing. This will result in a release of a higher amount of medicament than is desired. ;It is important for the health of the animal that the animal does not receive ;2 ;James & Wells Ref: 129742/47 SA ;particular medicaments which are in excess of a specific threshold. Exceeding this threshold may be harmful to the animal being treated, and may result in the animal developing undesired side effects. ;At present, the end caps in the prior art is moulded as a solid piece of plastics 5 material. To assist in the manufacture of the end cap, the end cap is specifically moulded with tapering sides to assist in the removal of the end cap from the mould. ;As discussed above, bolus housings are typically cylindrical or tubular in shape. The tapering of the sides of the end cap means that a substantial proportion of the sides of the end cap are not in contact with the body of the housing. ;10 This allows rumen fluid to enter into the small space between the sides of the end cap and the body of the bolus. Over time, this can result in leakage of rumen fluid into the end of the bolus housing. ;As can be appreciated, this will ultimately result in undesired erosion of the tablets at both end of the bolus housing. ;15 It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice. ;Ail references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their 20 authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country. ;25 It is acknowledged that the term 'comprise' may, under varying jurisdictions, be ;3 ;James & Wells Ref: 129742/47 SA ;attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term 'comprise' shall have an inclusive meaning - i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components 5 or elements. This rationale will also be used when the term 'comprised' or 'comprising' is used in relation to one or more steps in a method or process. ;Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only. ;DISCLOSURE OF INVENTION ;10 According to one aspect of the present invention, there is provided an end cap for a bolus housing, wherein the end cap includes a sealing portion which covers the open end of a bolus housing, and a skirt depending from the circumference of the end cap, ;characterised in that the skirt is configured such that the sides of the end cap is 15 substantially parallel to the side of the bolus housing, and the interior of the end cap substantially contacts the exterior of the bolus housing. ;In one embodiment the present invention includes a collar which surrounds at least a substantial portion of the bolus housing, ;and the skirt configured to engage with the collar such that the side of the end cap 20 is substantially parallel to the side of the bolus housing, and the interior of the end cap substantially contacts the exterior of the bolus housing. ;According to yet another aspect of the present invention, there is provided a method of manufacturing an end cap for a bolus housing, wherein the end cap includes a skirt configured to contact the exterior of the bolus housing, ;4 ;James & Wells Ref: 129742/47 SA ;characterised by the steps of: ;a) configuring an end cap with a skirt substantially parallel to the exterior of a bolus housing, and b) placing the end cap over one end of the bolus housing. ;5 A preferred embodiment has the additional steps of: ;c) placing a collar about the circumference of a bolus housing, and d) engaging the end cap with the collar such that the sides of the end cap substantially contact the bolus housing. ;The invention broadly relates to a bolus for use in ruminants, the bolus delivering 10 an active agent or agents to an animal. ;The housing of the bolus may be a plastic or alloy casing which is biologically inert. This ensures that there is no harm to the animal, should the bolus housing be retained in the rumen rather than be excreted. ;The end cap should be understood to mean an apparatus configured to cover one 15 end of a bolus housing to ensure that there is no passage of fluid from the external environment of the housing into the interior of the housing except at the open end of the bolus housing. ;The end cap may be made of any suitable material which is biocompatible. For example, the cover may be an alloy, but preferably the cover is manufactured from 20 plastics material. Plastics material is preferred as the material of choice for use in conventional plastic moulding techniques. ;However, persons skilled in the art will appreciate that the end cap may be manufactured from other materials such as an alloy. An alloy end cap may ;5 ;James & Wells Ref: 129742/47 SA ;undergo galvanic corrosion, ensuring complete disintegration of the end cap. ;The end cap should be understood to have a sealing portion to cover the open end of the bolus housing. The sealing portion is the portion of the end cap which is inserted into or otherwise covers the end of the bolus housing, sealing the end of 5 the bolus housing from the external environment. ;Preferably, the sealing portion is a two part assembly, including a sleeve with an aperture passing through one surface, and a plug for the aperture. However, persons skilled in the art will appreciate that the cover may be a single piece construction. ;10 Preferably, the mating surfaces of the plug and sleeve are tapered. This allows for easy removal of these components from a moulding die. ;The skirt should be understood to mean the portion of the end cap which envelops at least a portion of the exterior of the bolus housing. Preferably, at least approximately 25 mm of the length of the bolus housing is covered by the skirt of 15 the end cap, although persons skilled in the art will appreciate that this is not meant to be limiting and end caps of varying lengths may be used. ;The collar should be understood to mean a ring-like member which is placed over the outside of the bolus housing prior to inserting the end cap. ;Preferably, the collar is provided with a recess around the upper inside perimeter of 20 the collar. ;Preferably, the end of the skirt is configured with a projection which may be inserted into the recess of the collar. However, persons skilled in the art will appreciate that the skirt and collar may be engaged in other ways. For example, the skirt may be provided with a recess into which a projection from the collar is 25 inserted. ;6 ;James & Wells Ref: 129742/47 SA ;It should be appreciated that the fitting between the skirt of the end cap and the collar of the end cap is similar to a tongue and groove joint. The surface of the skirt and collar which contacts the bolus housing should be understood to be substantially continuous. ;5 The method of interacting the skirt of the end cap with the skirt collar ensures that the end cap seals the bolus housing not only at its end but along a substantial portion of its sides. ;This reduces the potential for rumen fluid (or other fluids) entering the covered end of the bolus assembly via capillary action between the side of the bolus housing 10 and the interior of the end cap skirt. ;In use, the bolus housing is fitted with a collar. In some embodiments of the present invention, there may be a number of collars which inter-engage with one another to form a plastic coating for the bolus housing. ;The end cap is placed over one end of the bolus housing. The lip of the skirt 15 engages with the recess of the collar, locking the end cap in place, and holding the skirt in contact with the exterior of the bolus housing. This seals the covered end of the bolus housing from the external environment, ensuring that only controlled erosion from the open end of the bolus occurs. ;It should be appreciated that the present invention has a number of advantages 20 over the prior art: ;• It offers superior sealing qualities for boluses relative to end caps in the prior art; ;• It ensures that only controlled erosion of the bolus takes place; ;• It is relatively inexpensive to manufacture; ;7 ;James & Wells Ref: 129742/47 SA ;• Having tapering surfaces allows for the easy removal of moulded components from moulding dies. ;BRIEF DESCRIPTION OF DRAWINGS ;Further aspects of the present invention will become apparent from the following 5 description which is given by way of example only and with reference to the accompanying drawings in which: ;Figure 1 is a perspective view of the sleeve of the present invention; and Figure 2 is a side view of the sleeve; and ;Figure 3 is a perspective view of the plug of the present invention, and 10 Figure 4 is a perspective view of the collar of the present invention, and Figure 5 is a side view of the present invention. ;BEST MODES FOR CARRYING OUT THE INVENTION ;In Figure 1, the sleeve (generally indicated by arrow 1) includes a top (2), with an aperture (3). The sides of the aperture (4) are angled approximately 20° from the 15 vertical, such that the aperture tapers outwards from the top (2) to the underside of the top (not shown). ;The sleeve (1) includes a skirt (5) descending from the circumference of the top (2). At the lowest portion of the skirt (5), a lip (6) is provided. ;In Figure 2, it should be appreciated that the interior surface (7) of the lip (6) is 20 contiguous with the interior surface (7) of the skirt (5). ;8 ;James & Wells Ref: 129742/47 SA ;The plug (8) is illustrated in Figure 3. The plug (8) has an insert (9) which is inserted into the aperture of the sleeve (not shown). The perimeter (10) of the plug (8) bears against the underside of the top (not shown) of the sleeve (not shown). ;The mating surface of the plug (11) has a taper of approximately 20® from the 5 vertical corresponding to the equivalent tapering of the sleeve (not shown). ;A collar (12) engages with the lip (not shown) of the skirt (not shown) of the sleeve (not shown). The interior of the collar (12) includes a recess (13) which mates with the sleeve lip (not shown) to lock the sleeve (not shown) and corresponding plug (not shown) to the collar (12) ;10 A complete bolus assembly (14) including the sleeve (1) and plug (8) is depicted in Figure 5. The sleeve (1) engages with a collar (12) which surrounds the housing (15) of the bolus (14). ;The lip (6) of the sleeve (1) is inserted under the collar (13), locking the skirt (5) of the sleeve (1) against the housing (15). ;15 This provides much better protection for the tablets (16) of the bolus (12) from undesired egression of rumen or other types of fluids (not shown) into the covered end (17) of the bolus (12). ;Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto 20 without departing from the scope thereof as defined in the appended claims. ;9 * </div>

Claims

<div class="application article clearfix printTableText" id="claims"> WHAT l/WE CLAIM IS:

1. An end cap for a bolus housing, wherein the end cap includes a sealing portion which covers the open end of a bolus housing, and a skirt depending from the circumference of the end cap, characterised in that the skirt is configured such that the sides of the end cap is substantially parallel to the side of the bolus housing, and the interior of the end cap substantially contacts the exterior of the bolus housing.

2. An end cap for a bolus housing as claimed in claim 1 which includes a collar which surrounds at least a substantial portion of the bolus housing, and the skirt configured to engage with the collar such that the side of the end cap is substantially parallel to the side of the bolus housing, and interior of the end cap substantially contacts the exterior of the bolus housing.

3. An end cap as claimed in either claim 1 or claim 2 wherein the sealing portion is a disc covering the open end of a bolus housing.

4. An end cap as claimed in either claim 1 or claim 2 wherein the sealing portion is a plug inserted into the open end of a bolus housing.

5. An end cap as claimed in either claim 1 or claim 2 the sealing portion is a plug inserted into an aperture in the end cap.

6. An end cap as claimed in claim 5 wherein the contact surfaces between the plug and the aperture are tapered.

7. An end cap as claimed in any one of claims 1 to 6 wherein the skirt includes a projection about its lower edges.

8. An end cap as claimed in any one of claims 1 to 7 wherein the skirt includes a recess about its lower edges.

9. A collar for use with the end cap as claimed in any one of claims 2 to 7 wherein the collar includes a recess configured to mate with a projection of the skirt of the end cap.

10. A collar for use with the end cap as claimed in claim 8 wherein the collar includes a projection configured to mate with the recess of the skirt of the end cap.

11. A bolus housing incorporating an end cap as claimed in any one of claims 1 to 8.

12. A method of manufacturing an end cap for a bolus housing, wherein the end cap includes a skirt configured to contact the exterior of the bolus housing, characterised by the steps of: a) configuring a end cap with a skirt substantially parallel to the exterior of a bolus housing, and b) placing the end cap over one end of the bolus housing.

13. A method of manufacturing an end cap for a bolus housing as claimed in claim 12 including the further steps of: c) placing a collar about the circumference of a bolus housing, and d) engaging the end cap with the collar such that the sides of the end cap substantially contact the bolus housing. 11 A An end cap substantially as described herein and with reference to the drawings. A collar for use with the end cap substantially as described herein and with reference to the drawings. A bolus housing substantially as described herein and with reference to the drawings. An method of manufacturing an end cap substantially as described herein and with reference to the drawings. BOMAC RESEARCH LIMITED WILLIAM ERNEST POMROY MARTIN JOHN WHITEHEAD WAYNE FREDERICK LEECH By their attorneys JAMES & WELLS </div>