WO2011106802A1

WO2011106802A1 - Applicator of semiliquid/semisolid medical and veterinary preparations

Info

Publication number: WO2011106802A1
Application number: PCT/ZA2010/000010
Authority: WO
Inventors: Jacobus Adriaan Wessels
Original assignee: Jacobus Adriaan Wessels
Priority date: 2010-02-23
Filing date: 2010-02-23
Publication date: 2011-09-01

Abstract

An applicator [1] is provided for dispensing a predetermined quantity of semiliquid preparation into a body cavity especially the vagina, but also possibly the rectum, mouth, nose and ear. The applicator comprises a barrel [2] having an open delivery end [3] and an opposite operating end [4], and a plunger [5] movable along the length of the barrel between a charged position in which it is located towards the operating end of the barrel and a discharged position in which it is located towards the delivery end of the barrel. Biasing means [11] have a loaded condition corresponding to the charged position of the plunger and an unloaded position corresponding to the discharged position of the plunger with the biasing means being operative to move the plunger from its charged position to its discharged position upon release thereof. Manually releasable catch means [12] hold the biasing means in the loaded condition. A safety unit [15, 16] prevents operation of the manually releasable catch means unless the plunger is in its charged position. Preferably, an operating stem is provided for moving the plunger from its charged position to its discharged position and the operating stem and plunger are movable to their loaded and charged positions independently of each other so that the biasing means may be charged whilst the plunger remains in its discharged position.

Description

APPLICATOR FOR SEMILIQUID / SEMISOLID MEDICAL AND VETERINARY PREPARATIONS

FIELD OF THE INVENTION

This invention relates to an applicator for semiliquid / semisolid (hereinafter referred to as semiliquid) medical and veterinary preparations such as creams, gels and pastes and, more particularly, the invention relates to an applicator that is particularly suitable for dispensing a predetermined quantity of the semiliquid preparation.

Still more particularly, the invention relates to an applicator that is suitable for dispensing a predetermined quantity of semiliquid preparation into a body cavity especially the vagina, but also the rectum, mouth, nose and ear. It will be quite apparent to those skilled in the art that the applicator can also be used to excellent effect in numerous veterinary applications in which an animal such as a cat or dog can bite onto the hard barrel of an applicator as the veterinary preparation is administered.

BACKGROUND TO THE INVENTION

Vaginal applicators that are presently available on the market are, as far as applicant is aware, either made from plastic or cardboard. In general these applicators consist of a barrel for receiving the medical preparation and a plunger for expelling the preparation from the barrel. The applicators may be pre-filled or user filled and may be designed to be re-usable or disposable single-use products. Numerous different vaginal medical preparations are in common use or are planned for future use and these include contraceptive and microbicidal preparations as well as numerous different medicinal and lubricating preparations.

In many instances, for the medical preparation to be effective, it is important that the clinically tested dose is used. Under-dosing may lead to the preparation not being effective and may even lead to development of a resistance to a particular active ingredient. This can occur if the usual barrel is not properly filled, typically by not forcing the plunger fully to the loaded position when introducing medical preparation into the barrel, for example by squeezing it from a tube. It can also occur by not fully expelling medical preparation from the barrel, typically by exerting insufficient manual force on a stem that causes the plunger to move it to its designed terminal position at the delivery end of the barrel. Overdosing, on the other hand, can occur if the barrel is capable of accommodating more than the recommended dose. Apart from wasting generally costly preparation, this may also result in abnormally high levels of an active ingredient being introduced with possibly undesirable resultant side effects.

It is therefore important, at least in many applications, that an applicator is able to deliver the correct predetermined quantity of a medical preparation. This involves, in the instance of user filled applicators, properly filling the applicator and, in the instance of either prefilled or user filled applicators, ensuring that the entire predetermined quantity is discharged.

Clearly, from a cost perspective, it is desirable to employ a re-usable applicator that can be filled from a multi-dose tube or other container. A reusable applicator must be easy to clean and have some means to prevent contamination. OBJECT OF THE INVENTION

It is an object of this invention to provide an applicator that is more reliable in delivering a predetermined quantity of a medical preparation and that may have various other advantages when compared to the prior art.

SUMMARY OF THE INVENTION

In accordance with this invention there is provided an applicator for a semiliquid medical or veterinary preparation, the applicator comprising a barrel having an open delivery end and an opposite operating end, and a plunger movable along the length of the barrel between a charged position in which it is located towards the operating end of the barrel and a discharged position in which it is located towards the delivery end of the barrel, the applicator being characterised in that it includes biasing means that have a loaded condition corresponding to the charged position of the plunger and an unloaded position corresponding to the discharged position of the plunger with the biasing means being operative to move the plunger from its charged position to its discharged position upon release thereof, manually releasable catch means for holding the biasing means in the loaded condition, and a safety unit preventing operation of the manually releasable catch means unless the plunger is in its charged position.

Further features of the invention provide for the biasing means to be associated with an axially movable operating stem to bias the stem towards a position corresponding to the discharged position of the plunger; for the biasing means to be one or more springs; for the catch means to include a spring biased latch cooperating with a formation in the operating stem; for the safety unit to be a transfer element movable in unison with the plunger so that it enables operation of the manually releasable catch means only when it is in registration with a manually movable component of the releasable catch means; for the barrel to have an external removable and optionally disposable outer sleeve; for the outer sleeve to extend beyond the open discharge end of the barrel to occlude such end of the barrel and isolate it from body fluids, in use; for the outer sleeve to have connector means for. attaching it to a dispensing tube or other container; and for visible indicator means to be provided for indicating when the plunger is in its terminal loaded position.

It will be understood that in the instance that an operating stem is provided for moving the plunger from its charged position to its discharged position, the operating stem and plunger are movable to their loaded and charged positions independently of each other so that the biasing means may be charged whilst the plunger remains in its discharged position. Introduction of medical preparation into the barrel from the open discharge end of the barrel moves the plunger towards the operating end of the barrel such that only once the barrel is full is a transfer element in registration with a manually movable component of the releasable catch means. Accordingly, with a specifically designed barrel and plunger, the releasable catch means cannot be operated unless the plunger has been moved fully to the charged position corresponding to a particular quantity of semiliquid preparation having been introduced into the barrel in order to move the plunger.

In order that the above and other features of the invention may be more fully understood one embodiment thereof as well as variations thereof will now be described with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:-

Figure 1 is a front elevation of one embodiment of the invention;

Figure 2 is a sectional elevation taken along line II - II in Figure 1 ; Figure 3 is an enlarged sectional elevation of the operating end of the applicator when the plunger is between its discharged position and a charged position being a position in which the manually operable release catch cannot be operated;

Figure 4 is the same as Figure 3 but showing the arrangement with the plunger in its fully charged condition and the catch means in a condition in which it is operable; and,

Figure 5 is an elevation illustrating the removable external sleeve and co-operating barrel of the applicator.

DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS In the embodiment of the invention illustrated in Figures 1 to 5 of the drawings, a vaginal applicator (1) for a semiliquid medical preparation comprises a barrel (2) having an open delivery end (3) and an opposite operating end (4). A plunger (5), in this instance of generally spherical shape, is movable along the length of the barrel between a charged position in which it is located towards the operating end of the barrel, as illustrated in Figures 2 and 4, and a discharged position in which it is retained within the barrel at the delivery end by means of an inwardly directed lip (6), as illustrated in dotted lines in Figure 2. A rearwardly extending strip (7) that communicates tangentially with the plunger is formed integral with it. The strip is located at one side of the barrel and serves the purposes of an indicator and of a transfer element for co-operation with the catch mechanism as described hereinafter.

The plunger is, apart from any friction between it and the barrel wall, freely movable within the barrel and is in cooperating relationship relative to an axially extending stem (8) that has an engagement flange (9) at its inner end for contacting the plunger and an operating handle (10) at its outer end. The flange has a cutout for accommodating the strip where it passes the flange.

Biasing means in the form of a compression spring, generally indicated by numeral (1 1 ), encircles the stem between the operating end of the barrel and the flange. The flange and the stem are thus biased, in the loaded condition, towards a position corresponding to the discharged position of the plunger and are able to move the plunger to its discharged position when the plunger is in its charged position.

The stem therefore has a loaded condition corresponding to the charged position of the plunger in which it is retained by a latch (12) against the action of the spring (see Figure 4), and an unloaded position corresponding to the discharged position of the plunger. The latch engages in a notch (13) in the stem to hold it longitudinally against the action of the spring. It will be understood that, once the latch is released, the stem and thus the plunger are moved under the action of the spring from the loaded and charged positions to the unloaded and discharged positions respectively. The latch forms part of a manually releasable catch means that includes a manually operable flexible release button (14) carrying a manually movable component (15) that is to release the latch when the release button is depressed and the plunger is in its charged position. A small frame (16) is interposed between the movable component (15) and latch (12) and is arranged such that the manually movable component simply enters the frame without releasing the catch in the absence of the strip (7) carried by the plunger (5) that serves as the transfer element.

The length of the strip is selected such that when the barrel is full and the plunger is in its charged position, only then is the end region of the strip in registration with the frame such that the movable component carried by the flexible release button can engage the frame by way of the strip so that the frame engages the latch to release it. In this manner operation of the manually releasable catch means is prevented unless the plunger is in its charged position and that only happens when the barrel is full because of the free-floating plunger and attached strip that serves as the transfer element defined above.

As indicated above, the strip that is attached to the plunger also serves the purpose of an indicator by virtue of coloured regions of the strip that are visible through an inspection aperture (17) at the operating end of the barrel. These coloured regions come into registration with the inspection aperture such that a red colour is visible initially and only when the plunger is in its fully charged position is a green colour visible through the inspection aperture. The barrel itself, in this embodiment of the invention, is designed to be maintained out of contact with body fluids by means of an external removable and optionally disposable outer sleeve (18) (see Figure 5) that is a frictional fit over the outer surface of the barrel. The outer sleeve, in its operative position, extends beyond the open discharge end of the barrel, as shown in Figure 2, to occlude the end of the barrel and isolate it from body fluids, in use. The outer sleeve has connector means the form, for example, of an appropriately dimensioned socket (19) for attaching it to a dispensing tube or other container from which medical preparation is to be sourced. In use, the biasing means may be charged whilst the plunger remains in its discharged position. Introduction of medical preparation into the barrel from the open discharge end of the barrel moves the plunger towards the operating end of the barrel such that only when the barrel is full is the strip in registration with the manually movable component of the releasable catch means. Accordingly, with a specifically designed barrel and plunger, the releasable catch means cannot be operated unless the plunger has been moved fully to the charged position corresponding to a particular quantity of semiliquid preparation having been introduced into the barrel in order to move the plunger. This, accordingly, ensures that a user fills the applicator with the correct amount of medical preparation. The sleeve serves firstly to prevent contamination from one use to the next as a small amount of medical preparation stays behind in the delivery end of the sleeve thereby creating a barrier between the outlet of the sleeve and the delivery end of the barrel. This is aimed at preventing body fluids from contacting the barrel itself. Secondly, the applicator cannot be filled if the sleeve is not on the barrel as the sleeve has the socket for connection to a supply tube, for example. Whilst it is generally possible for the sleeves to be reusable, it is preferred that they are disposable.

Numerous variations may be made to the embodiment of the invention described above without departing from the scope hereof. In particular, the transfer element could be a freely movable element located in a transverse hole in a piston rod carried by the plunger. In this arrangement the flexible release button or manually movable element simply needs to be in registration with the freely movable element in order to release the latch which only occurs when the plunger is in its charged position.

It is also possible that an outer part of the stem could be flexible and, especially, longitudinally extensible, such as by being made as a flexible sinuous or zigzag member. As exclusively tensile strength is required of at least the outermost part of the stem, that part of the stem could contract longitudinally once the stem is in its charged position in order to reduce the size of the applicator when charged. This arrangement could also prevent a user from pressing onto the stem in an effort to bypass the trigger button. That part of the stem could alternatively be simply a flexible piece of string.

Of course numerous other variations may be made without departing from the scope of the invention. In particular, the outer sleeve is not entirely necessary and the applicator could be designed for use without a replaceable sleeve. Of course the barrel could also have a removable and replaceable tip. Also, the plunger can assume any configuration, as will be quite apparent to those skilled in the art.

Claims

CLAIMS:

An applicator [1] for a semiliquid medical or veterinary preparation, the applicator comprising a barrel [2] having an open delivery end [3] and an opposite operating end [4], and a plunger [5] movable along the length of the barrel between a charged position in which it is located towards the operating end of the barrel and a discharged position in which it is located towards the delivery end of the barrel, the applicator being characterised in that it includes biasing means [11] that have a loaded condition corresponding to the charged position of the plunger and an unloaded position corresponding to the discharged position of the plunger with the biasing means being operative to move the plunger from its charged position to its discharged position upon release thereof, manually releasable catch means [12] for holding the biasing means in the loaded condition, and a safety unit [15, 16] preventing operation of the manually releasable catch means unless the plunger is in its charged position.

An applicator as claimed in claim 1 in which the biasing means is associated with an axially movable operating stem [8] to bias the stem towards a position corresponding to the discharged position of the plunger.

An applicator as claimed in either one of claims 1 or 2 in which the biasing means is one or more springs [11].

An applicator as claimed in claim 2 in which the catch means includes a spring biased latch [12] cooperating with a formation [13] in the operating stem,

An applicator as claimed in any one of the preceding claims in which the safety unit is a transfer element [7] movable in unison with the plunger so that it enables operation of the manually releasable catch means only when it is in registration with a manually movable component [15] of the releasable catch means.

An applicator as claimed in any one of the preceding claims in which the barrel has an external removable and optionally disposable outer sleeve [18].

An applicator as claimed in claim 6 in which the outer sleeve extends beyond the open discharge end of the barrel to occlude such end of the barrel and isolate it from body fluids, in use.

An applicator as claimed in either one of claims 6 or 7 in which the outer sleeve has connector means [19] for attaching it to a dispensing tube or other container.

An applicator as claimed in any one of the preceding claims in which visible indicator means [7, 17] are provided for indicating when the plunger is in its terminal loaded position.

An applicator as claimed in any one of the preceding claims in which an operating stem is provided for moving the plunger from its charged position to its discharged position and the operating stem and plunger are movable to their loaded and charged positions independently of each other so that the biasing means may be charged whilst the plunger remains in its discharged position.

11. An applicator as claimed in claim 10 in which the plunger is movable towards the operating end of the barrel by the introduction of semiliquid preparation into the barrel such that only once the barrel is full does that the safety unit enable discharge to be initiated.

12. An applicator substantially as herein described and exemplified with reference to the accompanying drawings.