MXPA99007222A - Applicator for semi-solid medications - Google Patents

Abstract

An applicator for semi-solid medications comprises a tubular body(20) having a rounded dispensing end (21) provided with at least one opening (26) and a grasping end (22), the inner surface of a proximal portion of said tubular body defining a reservoir for the medication, a plunger (30), initially housed inside the tubular body, which plunger is provided with a rod (31) and grasping means (33), a piston (40), positioned in sealing contact with the inner surface of said tubular body providing a closure for the medication reservoir, wherein said piston has a longitudinal hole (45) through which rod (31) of the plunger is disposed, and wherein said piston initially abuts on a stop means (25) when the applicator is received by the user, a coupling means (35, 46) between rod (31) and piston (40), a closure means for sealingly closing off said opening (26) on said dispensing end, wherein the plunger (30) is extractable from the tubular body until the rod (31) becomes engaged with the piston (40) by the coupling means, whereupon the plunger together with the piston is displaceable along the tubular body towards the dispensing end (21) for expelling the medication through opening (26), and wherein the stops means (25) is provided in the form of a projection on the inner surface of the tubular body.

Description

Applicator for semi-solid medications Sector of the technique to which the invention relates The invention relates to a new applicator, and more specifically, to a new pre-filled applicator for the administration of semisolid medications such as creams and similar to the vagina and other body cavities.

Description of the state of the art The use of vaginal applicators for the administration of drugs is already known in the art. Various applicators for the administration of semisolid medications to the vagina are on the market. In general, compliance with vaginal treatments with medications of this type depends to a large extent on the applicator used. That is why it is necessary to use applicators that are as comfortable and easy to use by the user as possible and that do not cause irritation or pain. They must also meet a series of additional requirements, such as simplicity and manufacturing economy. It is also very important that they can be used as a container for medication as well as a device for administration thereof, thus avoiding any manipulation by the user. This manipulation, apart from being uncomfortable and cumbersome, prevents guaranteeing the necessary hygiene conditions for this type of devices as well as the correct dosage of the medication. In order to be used as a container, it is necessary that the device can provide a hermetic closure of the compartment where the medication is stored. In this case, it is also important that the applicator be easy to fill with the medication at the factory.

Most commercial applicators do not meet many of these requirements. They usually consist of a straight and hollow cylindrical body of small diameter and of a driving rod displaceable within the cylinder, and are generally provided for repeated uses. One of the ends of said cylinder is open and generally contains an internal thread with the mission of splicing with a tube containing vaginal medication. To use the applicator, the medication tube must be screwed onto the open end of the applicator. It is then pressed on the opposite end of the tube, thus forcing the entry of medication into the applicator. Then, the tube is unscrewed and the applicator is ready for use. This type of applicators can not be used as a container, ie they can not be preloaded with medication, because they do not provide a hermetic closure, which means that the user must fill the applicator before each use, with the consequent possibility of dosage error, loss of hygiene and discomfort of the filling process for the user. Some applicators apt to be preloaded with medication have been described in the literature. US 2,630,804 describes a pre-filled vaginal applicator where for reasons of compactness the body of the applicator is presented in the form of a telescopic assembly comprising an inner tube and an outer tube. A piston is arranged by closing one end of said inner tube and the other end is closed by means of a plug. A telescopic rod is disposed inside the inner tube, through a hole in the piston. In use, the telescopic rod must extend first, then the telescopic cylinder assembly must be extended to its maximum extent by sliding the outer cylinder along the inner cylinder, and finally it must be pulled from the extended rod until it is assembled with the piston. Although it is a compact device, this applicator is difficult to use, since it takes three operations to assemble the applicator before use, and there is also the risk of disassembling the telescopic cylinders during use if the user pulls too hard during the operation. second operation. In addition, this applicator can cause discomfort during its use because its dispensing end is not rounded. US 4636,202 discloses a vaginal applicator provided with an automatic opening closure for the dispensing end of the body of the applicator. WO 93/21986 describes a vaginal applicator comprising a body with a cylindrical section of large diameter, a section of small diameter and an inclined transition section together with an unscrewable cap and a rubber piston provided with a rod. The unscrewable cap is used to close the dispensing end and also as a rod to push the piston rod and eject the medication. In use, the cap must be unscrewed, then inverted and reinserted into the large diameter section, and pushed to expel the medication. This applicator is difficult to use because it involves the disassembly and reassembly of the cap. For these reasons, it is necessary a new improved vaginal applicator that can solve these and other problems that will be evident throughout the description.

Description of the invention The aim of the present invention is to provide a vaginal applicator which can be used both as a container and as a medication application device, which contains a minimum number of parts, which is economical to manufacture and easy to assemble and fill with medication in the factory as well as making it easy and comfortable to use for the user.

This object is achieved with the device of claim 1. An example according to the invention is explained in more detail with reference to the drawings, where: Fig. 1 is an exploded view of the various elements that make up an applicator according to the present invention, Fig. 2 is a longitudinal section of the hollow tubular body of the applicator, Fig. 3 is a side view of the plunger, Fig. 4 is a front view of the plunger of Fig. 3, Fig. 5 is a partial section of the piston, Fig. 6 is an enlarged view of element A of Fig. 5, Fig. 7 is a longitudinal section of the cap, Fig. 8 is a cross section of the cap of Fig. 7, and Fig. 9 shows the applicator of the invention in different positions during its use: (a) applicator in the initial compact position, as received by a user; (b) applicator showing the plunger and piston in an assembled position, ready to discharge the medication; (c) applicator after use, showing the drive mechanism assembled at the end of its travel. To facilitate the understanding of the drawings, the cap has been omitted.

As shown in Fig. 1, a vaginal applicator 10, in accordance with this invention, consists essentially of four parts: a main tubular body 20, a plunger 30 and a piston 40, which together constitute the driving means for ejecting the contents , and a cap 50. As already mentioned above, this applicator is designed to be used both as a container and device for applying the dose of medication to be administered. To ensure its functionality a rigid material for the main body 20 and a flexible material for the piston 40 must be employed. The main body 20 has a closed dispensing end 21 and an open fastening end 22, as illustrated in Figure 2. This The body serves as a reservoir for the medication and also contains the drive mechanism housed therein. This main body 20 is formed by a hollow essentially cylindrical tube which is differentiated into two parts 23 and 24, formed coaxially and integrally with each other, which are separated by an annular projection 25 formed in the inner wall of the body 20. This projection or protrusion 25 serves to retain the piston in the compact, non-operative initial position of the applicator, as described below. The front part of the main body 23, close to the dispensing end 21, is formed by a cylindrical section of constant diameter. The inner cavity of this section constitutes the medication reservoir. This section ends in a closed free end of rounded shape 21, which facilitates the insertion of the applicator 10 in the vagina, without discomfort or irritation for the user. This rounded end 21 has a plurality of holes 26, preferably located equidistantly, which allow the radial exit of the medication when the piston-piston mechanism is actuated, thus achieving a better distribution of the drug in the area to be treated. As will be apparent to those skilled in the art, it is possible to modify both the number of holes and their shape and dimensions, all of these modifications remaining within the scope of the invention. The rear portion 24 of the main body 20 is also cylindrical, and at its open rear end 22 there is a radially outwardly extending wing 27 formed on the outer surface of the applicator body, which serves as a support to assist the wearer to hold the applicator during use. In a preferred embodiment, the diameter of this rear part 24 widens slightly towards the rear end 22 of the body of the applicator, so that at the end 22 the diameter is slightly greater than the diameter in the central area near the annular projection 25. This arrangement allows evacuate the air contained within the applicator during the assembly thereof, as explained below. Since the diameter of the section 24 is greater than that of the piston, it can move easily and without friction to the anchoring point in the form of an annular projection 25 located in the central area of the applicator, which allows air to escape. If the diameter were constant along the entire body of the applicator, the piston would fit against the wall of the applicator at all times, which would prevent the exit of the air contained therein. This diameter increase of the section 24 may be so small that although sufficient to allow air to escape, it may not be detectable by the naked eye. The drive to eject the medication slides inside the cylindrical tube of the applicator. This mechanism is constituted by a system of piston 30 and piston 40. The piston 30 consists of three parts, molded in a single piece, as shown in Figures 3 and 4; an end 31, which we will call the inner end because it is always housed inside the main body 20, a central part 32 and an outer end 33. The inner end 31 is formed by a cylindrical rod of a diameter much smaller than the body 20, suitable for sliding through the piston as explained below, and having a projection or apical annular projection 34. At a certain distance, which will be a function of the size of the piston, there is a groove or annular channel 35. The projection 34 and the groove 35, respectively, serve to interact with the piston to fix it in the operative or extended position of the plunger-piston system, ready to discharge the medicament. This cylindrical rod 31 is the extension of a cruciform section rod 32, of a width slightly smaller than the internal diameter of the applicator body, but sufficient to make contact with the interior of the applicator and to retain the piston 30 in the initial compact or retracted position of the applicator. Applicator This cruciform design has been used for this piece because it is the one that provides maximum stiffness and stability with a minimum of material. However, as will be apparent to one skilled in the art, other designs for this piece are possible, all of which are encompassed within the scope of the present invention. This cruciform rod 32 is provided at its end with fastening means 33 to facilitate the actuation of the piston-piston system during the use of the applicator, which in the preferred embodiment shown in the drawings is shown in the form of an essentially circular ring 33 with a hole 36 for the insertion of a finger. The junction zone between 32 and 33 is molded in the form of a disk 37, which serves to limit the advance of the piston-piston system within the body 20 during ejection of the medicament. The length of the sections 31 and 32 is such that when the disc 37 is applied against the end 22 of the body 20 in the operative position of the driving mechanism, ie when the piston and plunger are assembled, the piston 40 is located in the dispenser end 21 and practically all the medication has been expelled, as shown in Figure 9c.

The piston 40, shown in Fig. 5, is designed to be assembled with the plunger 30 and to constitute the drive system for ejecting the medicament. The piston 40 fits perfectly within the section 23 of the body of the applicator, thus providing a closure of the compartment where the medicament is housed, and when the applicator is received by the user it rests against the annular projection 25. The piston 40 includes a essentially cylindrical central section 41, which constitutes the piston body, a channel 42 and a sealing or sealing circumferential skirt or skirt 43. In the preferred embodiment, shown in Fig. 5, the central section 41 ends in a rounded projection 44 , which is similar in shape and dimensions to the rounded end of the applicator, so that the maximum possible amount of medication can be expelled. As will be evident to those skilled in the art, it would be possible to use a piston where the central section 41 was flat, but in that case the efficiency of the discharge would be less as some of the contents would be left undone. The central section 41 of the piston is longitudinally traversed by a hole 45, as illustrated in FIG. 5, of slightly greater diameter than that of the rod 31 of the plunger, which allows the assembly and functionality of the plunger-piston drive system. At the lower end of this hole there is an annular projection 46 formed on its wall so that the diameter of the hole 45 at this point is slightly smaller than that of the rod 31, as shown in Fig. 6. The reduction in diameter corresponds approximately to the dimensions of the groove 35 of the rod 31 of the plunger. As shown in Fig. 5, at the upper end of the hole 45, the diameter increases slightly, forming a recess 47, so that the increase in diameter exactly corresponds to the apical annular shoulder 34 of the plunger. In this way, the pairs of elements 46-35 and 47-34 act by retaining the piston in an integral or fixed position at one end of the piston, allowing the discharge of the medication and preventing the accidental disassembly of the piston-piston system during the use of the applicator. . The piston also includes a skirt or sealing flange 43 for the purpose of sealing against the inner walls of the tubular body 20, which completely surrounds the central section 41, leaving a channel 42 therebetween. This flange 43 has on its outer surface an annular projection 48 which fulfills two functions. On the one hand, it interacts with the annular projection 25 of the main body 20, fixing the plunger-piston drive system in the compact initial position of the applicator and defining the medication reservoir. On the other hand, due to its flexibility, conferred by the construction material and the channel 42, it can be dimensioned so that its size is slightly larger than the inner diameter of the section 23 of the body of the applicator, thus providing a more airtight seal of the body. compartment where the medicament is located, and allowing the total evacuation of the medicament in contact with the interior walls of the applicator, without preventing at the same time the easy sliding of the piston within the section 23 during the use of the applicator. When the piston 40 pressed against the cruciform section 32 is inserted into the preloaded tubular body 20, the protrusion 48 of the piston passes over the annular projection 25, so that the lower end of the protrusion 48 in Fig. 5 is supported against the annular projection 25 to hold the piston 40, when the plunger is retracted, as shown in Figure 9b, until the rod 31 is assembled with the piston 40 by means of the groove 35 and the annular projection 46. The distance between the annular projection 25 and the trailing end 22 of the tubular body corresponds essentially to the distance between the disk 37 and the lower end of the projection 48, when the piston abuts against the cruciform section 32 in Figure 9a. In this position the rod 31 extends to the dispensing end 21 of the tubular body. The part 24 of the tubular body is preferably longer than the part 23, so that in the position of Figure 9b the cruciform section 32 is guided within the part 24 over a short distance. The applicator 10 also includes a cap 50 that covers the dispensing end. The function of this cap is to seal the dispensing orifices 26 tightly. As illustrated in Figures 7 and 8, the cap 50 has essentially the same shape as the dispensing end and comprises a cylindrical body that is open at one end 51 and closed by the opposite end 52. In a preferred embodiment, shown in the drawings, protrusions 53 are provided on the inner surface of the cap 50, whose size, shape and number correspond to those of the orifices 26 of the dispensing end. of the applicator, so that they fit perfectly with these holes and provide a hermetic seal that prevents the exit of the medicament contained in the applicator. As shown in the preferred embodiment described in the drawings, one or more internal annular projections 54, parallel to each other, can be optionally arranged on the inner wall of the cap to fit against the outer wall of the applicator body, thus providing a more effective closure. Finally, in order to ensure that the cap 50 is correctly fixed on the dispensing end, longitudinal projections 55, equiangularly distributed and whose number may vary within the scope of the present invention, can be arranged on the inner surface of the cap. By way of example, Figures 7 and 8 show a cap having four of these projections 55. The open end 51 of the cap 50 is flared to form a circular wing extending radially outwardly 56 to assist the user in removing the cap. cap. The assembly of the applicator is carried out by assembling, two by two, the elements described above, as described below. The piston 40 is first fitted with the piston 30. Specifically, the rod 31 of the piston is passed through the hole 45 of the piston until the piston makes contact with the cruciform section 32 of the piston. Because the piston is constructed of a relatively flexible material, it is easily deformed under the pressure exerted by introducing the rod 31, so that it can be passed through the piston, even though the apical annular shoulder 34 of the rod larger diameter than the orifice 45 of the piston. Next, the cap 50 is fixed on the dispensing end 21 of the body of the applicator 20. The body-cap assembly is placed in a vertical position, so that the open end 22 is located at the top and a predetermined quantity of the drug to be administered is dosed. through the open end 22, so that it is housed in the front part 23 of the body of the applicator. The assembled plunger-piston system is then introduced through the open end 22 and pressure is exerted until the protrusion 48 projects past the annular shoulder 25. At this time the disc 37 of the plunger will rest against the end 22 of the applicator. Because the section 24 of the main body 20 is slightly conical, as described above, the piston 40 does not provide a seal of the compartment where the medicament is housed until it rests against the annular projection 25, thereby the air contained within the applicator can be evacuated, thus avoiding overpressures in the medicament reservoir and allowing the storage of the vaginal medication in an airtight and substantially evacuated air environment. At this point, the applicator is already assembled and ready for use. As will be apparent to those skilled in the art, because the drive mechanism is housed inside the body of the applicator, the applicator of the present invention constitutes a truly compact device that occupies a minimum packing space. The device described in this invention is very easy and convenient to use, mainly because its end is rounded, which does not produce irritation or pain during its use, and because it does not require complicated manipulations of the same by the user before using it. The mode of use of the applicator of the present invention, which is preloaded with the desired amount of medicament, can be described in two stages, as illustrated in Fig. 9: 1.- Assembly of the plunger-piston drive system: With the applicator 10 in the compact initial position shown in Fig. 9a held in one hand, the index finger of the other hand is inserted through the ring 33 of the plunger and pulled, gently and slowly out of it, making passing the rod 31 of the plunger through the hole 45 of the piston until the piston is assembled with the plunger. At this point, the groove 35 and the annular shoulder 34 of the plunger will have engaged the annular protrusion 46 and the recess 47 of the piston, respectively, thereby securing the piston at one end of the plunger, as shown in Fig. 9b. 2.- Discharge of the medicament: The cap 50 is removed and, holding the applicator by the end 22 between the thumb and the rest of the fingers and with the index finger passed through the ring 33, the applicator is inserted by its rounded end 21 in the vagina as deeply as possible. In general, the user will have an indication that the applicator has been introduced to an adequate depth when the fingers holding the end 22 contact the area around the vaginal orifice. It should be taken into account, however, that the depth of insertion may vary in some women depending on the size of their vagina, so the insertion of the applicator should always be within the comfort limits for the user. Once the applicator is inserted, the ring 33 is pushed with the index finger toward the dispensing end 21, which causes the piston to exert pressure on the medication, which then emerges through the holes 26 into the vagina. The ring 33 should be pushed as much as possible, i.e. until the disc 37 contacts the end 22 of the body of the applicator, as shown in Fig. 9c. In this way, substantially all of the medication will have been dispensed. At this point, the applicator is removed and discarded. As will be apparent to those skilled in the art, the present invention is not limited to the preferred embodiment shown in the appended figures, it being possible to carry out various modifications and changes, for example of dimensions and materials, within the scope of the invention. Likewise, the applicator of the present invention can be used to administer medicaments to other body cavities other than the vagina, such as the anus, in which case it may be necessary to modify the diameter and / or length of the applicator to adapt it to these uses. .

Claims (16)

1. - Applicator for semisolid medications comprising a tubular body having a rounded closed dispensing end provided with at least one hole and an open fastening end where the rounded dispensing end is formed integrally with the tubular body and where the inner surface of an anterior part of said tubular body defines a reservoir for the medicament, a plunger, initially housed inside the tubular body, which is provided with a rod and means of attachment, a piston located in contact with the inner surface of said tubular body providing a closure of the medicament reservoir, wherein said The piston has a longitudinal hole through which the rod of the piston is disposed, and wherein said piston initially rests against a retaining element in the form of a projection on the inner surface of the tubular body when the applicator is received by the user, elements of interaction between the rod and the piston arranged in the hole or the piston and the inner end of the rod and removable closing means for sealingly closing said hole in said dispensing end, where the plunger is removable from the tubular body until the rod is assembled with the piston through the elements of interaction, after which the plunger together with the piston is movable along the tubular body towards the dispensing end to eject the medicament through the orifice.

2. - An applicator according to claim 1, wherein the retaining element is an annular projection.

3. An applicator according to claim 1, wherein the rear part of the tubular body between the retaining element and the fastening end has a diameter that increases slightly in the direction of the dispensing end to allow air to escape during assembly of the applicator.

4. - An applicator according to claim 1, wherein the removable closure means comprise a removable cap.

5. - An applicator according to claim 1, wherein the plunger, the rod and the fastening means are formed by a single piece.

6. - An applicator according to claim 1, wherein the dispensing end of the tubular body is provided with a plurality of holes, which are covered by a removable cap.

7. - An applicator according to claim 6, wherein the cap has on its inner surface a plurality of projections, which fit into the holes of the dispensing end of the tubular body.

8. An applicator according to claim 1, wherein the retention element in the form of a projection on the inner surface is located towards the middle of the tubular body, and wherein the length of the piston corresponds essentially to the length of the tubular body.

9. An applicator according to claim 1, wherein said piston comprises an essentially cylindrical central body traversed longitudinally by an orifice and a sealed rim, which completely surrounds said central body, leaving a channel between said central body and said sealing rim, and wherein said rim The sealant has an annular projection on its outer face.

10. An applicator according to claim 9, wherein the central body of said piston terminates at its upper end in a rounded projection that is similar in shape to the dispensing end of the applicator to minimize the amount of medicament remaining undispensable.

11. - An applicator according to claim 1, wherein said means for fastening said plunger comprise a ring for operating said plunger.

12. An applicator according to claim 1, wherein the rod has a diameter suitable for sliding through the hole of the piston and contains elements interacting with the piston, said rod being the extension of a cross-sectional rod of width slightly smaller than the inner diameter of the tubular body, and wherein said cruciform rod ends in a ring to facilitate the operation of the plunger.

13. An applicator according to claim 1, wherein the fastening end of the tubular body extends radially outwardly forming a wing to assist the user in holding the applicator.

14. - An applicator according to claim 4, wherein the open end of the cap is flared to form a wing extending radially outward to assist the user in removing said cap.

15. An applicator according to claim 4, wherein said cap is additionally provided with one or more internal annular projections on its inner wall to improve the closure.

16. - An applicator according to claim 12, wherein there is an annular recess provided in the upper end of the longitudinal hole for interacting with an annular projection on the end of the rod and there is an annular projection located at the lower end of the longitudinal hole to interact with a groove on the rod.